The Flame Retardant Cyclic Olefin Copolymer Composites with Boric Acid Modified ZSM-5 Synergists

The Flame Retardant Cyclic Olefin Copolymer Composites with Boric Acid Modified ZSM-5 Synergists | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The Flame Retardant Cyclic Olefin Copolymer Composites with Boric Acid Modified ZSM-5 Synergists Xiaokun Zhai, Jiajia Gu, Qin Ma, Yuwei Jin, Ruiyan Zhang, Faliang Luo This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3915796/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 19 Sep, 2024 Read the published version in Journal of Polymer Research → Version 1 posted 5 You are reading this latest preprint version Abstract Cyclic olefin copolymer exhibits promising alternative of thermal insulation foam in building fields. However, it is challenging to improve COC flame retardant behavior due to macromolecular chain with carbon and hydrogen elements. Herein, we utilize boric acid modified ZSM-5 (BZ5) as synergist in order to achieve the intumescent flame retardant (IFR) COC composite. The surface morphology, distribution of flame retardants, flame retardancy and morphology and structure of carbon residue of the composite were studied by SEM, EDS, LOI, CCT and FTIR characterizations. With adding BZ5 as a synergist, the LOI value can reach up to 28.5%, which is much higher than that of 15.3% for neat COC. Char residue content increased from 0.97% to 19.7% with BZ5 as a synergist in the COC composite. According to SEM and FTIR results, dense microscopic carbon residue structure after boric acid modification. The study shows that the modification of boric acid with appropriate content can improve the flame retardancy of COC. flame retardancy cyclic olefin copolymer ZSM-5 intumescent flame retardant Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 1. Introduction Cyclic olefin copolymer (COC) is a kind of high-valued thermoplastic plastic composed of cyclic olefin and α-olefin portion [ 1 ]. At present, most of the COC structures are ethylene/norbornene (E/NB) copolymers. Different from traditional linear polyolefin, COCs have excellent optical properties with higher transparency, and they exhibit higher glass transition temperature (T g ), excellent moisture resistance, chemical stability, high biocompatibility and strong dielectric electrical characteristics, etc., therefore they are widely used in optical devices, capacitor films and medicine, packaging fields [ 2 – 4 ] In particular, the COC performances depend on their NB content, and the higher NB content, the higher T g and thermal deformation temperature [ 5 ]. Recently, Zhang et al. [ 6 ] produced COC foam with excellent thermal insulated performance, which show great potential in building fields. However, COCs are easy to be ignited by external fire sources due to COC macromolecular chain with carbon and hydrogen elements. When exposed to combustion, COC could release large amount of heat, smoke and even toxic gases, and result in the concern of casualties and property damage. The shortage of high flammability limits the application of COC materials in many important fields, therefore it is urgent and critical to improve COC flame retardant performance. At present, there are two ways to improve flame retardant performance, additive type and reactive type. Among all added flame retardants, halogen flame retardants present the advantages of high flame retardancy efficiency and without compromising mechanical properties. But halogen flame retardancy will release burned and toxic smoke leading into serious damage to the environment and human health [ 7 ]. Nowadays, the flame retardant products are required to show green and environmental protection. The intumescent flame retardant (IFR) with low smoke, low toxicity and high flame retardant efficiency has attracted more attention [ 8 ]. The IFR could delay further combustion and fire spread due to the formation of carbonized layer. According to the fire tetrahedral theory, heat, fuel, oxygen and chain reaction are four key elements for flame combustion, and thus combustion will be prevented from one or more elements separation. IFRs effectively protect the polymer from further combustion by forming carbonized layer on the surface, and prevent the oxygen diffusion and inhibit the mass transfer of combustible gas, and thus delay the degradation of the polymer and reduce smoke generation [ 9 , 10 ]. Moreover, synergist addition could improve the flame-retardant efficiency without attenuating physical and chemical performance. Synergistic effect in flame retardancy is defined as two or more components combined performance is greater than that the sum of each component individual used. The common synergists of IFR includes metal oxides [ 11 , 12 ], organic montmorillonite [ 13 ], sepiolite [ 14 , 15 ] and zeolite molecular sieve [ 16 – 18 ]. Bernardes at al. [ 19 ] found that H-ZSM-5 could act as catalyzer to cause the reaction between ammonium polyphosphate (APP) and pentaerythritol (PER), and thus the high acid center concentration is conductive to the formation of expansion precursors. Wu at al. [ 20 ] studied the effect of boron modification on the acidity of ZSM-5, and the results showed that with the increase of boron content, the acid content of the weak acid site of the molecular sieve increased after boron modification. Herein, we utilize ZSM-5 with various boric acid content as IFR synergistic agents to improve COC flame retardant performance. APP and PER were incorporated to develop COC composite. The boric acid modification was characterized by SEM with EDS scanning. And boric acid contents were analyzed by XPS and FTIR. The subsequent flame-retardant performance of COC composites were characterized by imiting oxygen index (LOI), vertical burning (UL-94) and cone calorimeter test (CCT). The results showed that boron modified ZSM-5 is an efficient IFR synergistic agent, which can improve the flame retardancy of COC composites. 2. Experimental Section 2.1. Materials COC (CAS:26007-43-2) was derived from TOPAS Advanced Polymers GmbH. ZSM-5 (SiO2/Al2O3 = 25) employed in this investigation was purchased from Nankai University Catalyst Co., Ltd. Boric acid (H 3 BO 3 , CAS:10043-35-3) and pentaerythritol (PER, CAS:115-77-5) were procured from Sinophosphate Chemical Reagent Co., Ltd. Ammonium polyphosphate (APP, CAS:68333-79-9) was obtained from Hangzhou Jelsi Flame Retardant Chemical Co., Ltd. 2.2. Preparation of B modified ZSM-5 (BZ5) Firstly, 15 g of ZSM-5 was added into 100 mL of deionized water, and then evenly stirred into the ultrasonic instrument, and the power was set to 50%. After 10 minutes of ultrasonication 0.789 g of H 3 BO 3 was added, and then ultrasound for 30 min. After centrifugation and overnight drying at 110 ℃, the molecular sieve sample obtained was recorded as 5BZ5. The rest remained unchanged, and the samples obtained by changing the addition amount of B(OH)3 to 1.667 g, 2.647 g, 3.750g, 5.000g, 6.429g and 15.000g were recorded as 10BZ5, 15BZ5, 20BZ5, 25BZ5, 30BZ5 and 50BZ5, respectively. 2.3. Fabrication of COC and COC composites Firstly, COC was vacuum-dried at 50 ° C for 12 hours, and APP, PER, ZSM-5 and a series of BZ5 samples were dried under the vacuum at 80°C for 12 hours. PLA and PLA composites were fabricated via a twin-screw extruder (SJZS-10 A, China) in the temperature ranged from 185°C to 200°C with a screw speed of 30 rpm. The formula composition and labeling of PLA and PLA composites are shown in Table 1 . Table 1 Composition of COC and composites Sample Composition (wt.%) COC APP: PER (3:1) ZSM-5 5BZ5 10BZ5 15BZ5 20BZ5 25BZ5 30BZ5 50BZ5 COC 100 COCs 75 25 COCs/ZSM-5 75 24 1 COCs/5BZ5 75 24 1 COCs/10BZ5 75 24 1 COCs/15BZ5 75 24 1 COCs/20BZ5 75 24 1 COCs/25BZ5 75 24 1 COCs/30BZ5 75 24 1 COCs/50BZ5 75 24 1 2.4. Characterizations Fourier transform infrared spectra (FTIR) (Spectrum Two, Perkin Elmer Instruments Co., Ltd., USA) were performed within the wavenumber range of 4000-400cm − 1 by Attenuated Total Reflectance (ATR) technique at room temperature. X-ray photoelectron spectrometer (XPS) (AXIS SUPRA+, Shimadzu Corporation Co., Ltd., Japan) was used to perform elemental analysis of B/Z5. The fire behavior for all samples were evaluated by limiting oxygen index (LOI), vertical burning (UL-94) and cone calorimeter test (CCT). The LOI was tested with a Digital Oxygen Index Tester (5801A, Suzhou Yangyi Vouch Testing Technology Co., Ltd., China) with dimensions of 130 × 6.5 × 3 mm 3 according to ASTM D2863-97. The UL-94 test was performed on a Horizontal-vertical Burning Tester (5402, Suzhou Yangyi Vouch Testing Technology Co., Ltd., China) with the dimension of 130 × 13 × 3 mm 3 according to ASTM D3801. The CCT was carried out on cone calorimeter (6810, Suzhou Yangyi Vouch Testing Technology Co., Ltd., China) with dimensions of 100 × 100 × 3 mm 3 according to ISO 5660 with a heat flux of 35 kW/m 2 . X-ray diffraction (XRD) was carried out using a powder diffractometer (D8 ADVANCEA25, Bruker AXS Co., Ltd., Germany) at Cu K α radiation with the wavelength of 1.54 Å (λ = 1.54 Å) at room temperature. All the samples were dried in vacuum at 130°C for two hours before XRD test to remove moisture. Morphology was observed by Scanning Electron Microscopy (SEM) (ZEISS EVO18, Carl Zeiss AG Co., Ltd., Germany) equipped with energy dispersive X-ray spectroscopy (EDS) at 15.00 kV. To investigate the thermal stability of samples, thermogravimetric analysis (TGA) was performed on TA Instrument (Pyris 1, Perkin Elmer Instruments Co., Ltd., USA), all of the specimens were heated from 50 to 790°C at a heating rate of 10°C/min under N 2 atmosphere with flow rate of 50 mL/min. Temperature programmed desorption of NH 3 (NH 3 -TPD) was tested on a chemisorbed instrument (Model: AutoChem1Ⅱ2920, USA). All samples were heated at a heating rate of 10 ℃/min to 300 ℃ under a helium flow rate of 30 ml/min, pre-treated for 1 hour, then cooled to 120 ℃, and a mixture of NH 3 /He (volume ratio = 15/85) was introduced for adsorption. For gas desorption, after helium purge, all samples were heated from 120 ° C to 650 ° C at a rate of 10 ° C /min. 3. Results and discussions 3.1 Characterization of boric acid modified ZSM-5 samples In order to observe the boric acid modified ZSM-5 molecular sieve, ZSM-5 partilces were observed by SEM with EDS analysis. As shown in Fig. 3 a, the boric acid modified ZSM-5 have particles of ~ 2 µm, which is similar to unmodified ZSM-5 molecular sieve. It is indicated that boric acid modification could not change microscopic morphology of ZSM-5. According to EDS analysis, the boron, aluminum and silicon elements are uniformly dispersed on ZSM-5 molecular sieve. In order to analyze the boric acid content on ZSM-5 molecular sieve, both FTIR and XPS tests were performed on ZSM-5 and results were shown in Fig. 4 . The full-reflection infrared spectra of ZSM-5 with and without boric acid modification was shown in Fig. 4 a. The strong absorption peak at 1393 cm − 1 correlated to the B-O interaction [ 21 ], and B-O interaction gradually increased with increasement of absorption peak intensity (Fig. 4 b). In order to further quantitatively analyze boric acid content on ZSM-5, boric acid modified ZSM-5 with various content were characterized by XPS spectra, which is shown in Fig. 4 c. As shown in Fig. 3 d (b), the peak at 193.4eV related to B1s can be clearly observed. One can find that the peak intensity of spectrum increased, indicated that the boric acid content gradually increased. Accordingly, the loading of boric acid were 2.17%, 7.48%, 7.11%, 8.95%, 9.23%, 12.79%, 16.64%, respectively. 3.2 Distribution of flame retardants and BZ5 To observe the dispersion of modified ZSM particles in the COCs/25BZ5 composite, scanning electron microscope with EDS analysis was carried out and results are shown in Fig. 5 . The distribution of corresponding additive particles can be seen from each element, where phosphorus element (P) is the characteristic element of APP, oxygen element (O) is the characteristic element of PER, and silicon (Si) corresponding to ZSM-5 molecular sieve. It can be seen that the particles are uniformly dispersed in the COCs/25BZ5 composite. 3.3 Flame retardancy of COC and COC composites The LOI and UL-94 were used to study the flame retardancy of COC and its composites. The detailed data are shown in Table 2 . The LOI of neat COC was only 15.3%, and it does not have grade according to UL-94 test. After adding the IFR in COC composite, the LOI value gradually increase to 20.5%, and LOI value of the COC slightly increased to 23.8% with further incorporation of unmodified ZSM-5, and UL-94 level reached to V-2 level. With further adding boric acid modified ZSM-5 from 2.2% (5BZ5 sample) to 16.6% (25BZ5 sample), the LOI value first increased to 28.5% and then decreased down 24%. It indicated that there was an optimized boric acid content modification on ZSM-5. In the UL-94 test, although the ignition time of the material was improved, the COCs/25BZ5 sample did not reach V-0 level due to the obvious droplet phenomenon of the material, which always ignited the cotton pad. Table 2 LOI, UL-94 and CCT data of COC and COC composites Sample name LOI (%) UL-94 PHRR (kW/m 2 ) THR (MJ/m 2 ) Char yield (%) Av-EHC (MJ/kg) TSR (m 2 /m 2 ) AFTa(s) t1/t2 dripping rating COC 15.3 21.8/6.2 Y N.R. 1368.71 152.95 0.97 32.40 2443.63 COCs 20.5 2.8 /9.4 Y V-2 344.46 131.67 15.52 33.18 2801.23 COCs/ZSM-5 23.8 1.0/13.1 Y V-2 368.15 127.68 15.72 33.23 2372.78 COCs/5BZ5 22.5 25.7/11.1 Y N.R. 471.34 173.18 16.71 41.06 3957.27 COCs/10BZ5 23.2 19.3/3.44 Y V-2 405.97 183.09 18.02 47.50 3242.06 COCs/15BZ5 22.8 26.1/4.5 Y N.R. 436.79 176.54 17.52 48.10 3639.02 COCs/20BZ5 26.3 2.2 /12.8 Y V-2 374.08 174.87 19.37 36.24 3717.74 COCs/25BZ5 28.5 1.5/9.6 Y V-2 331.61 165.15 16.25 38.13 3733.48 COCs/30BZ5 25.2 19.3/5.4 Y V-2 412.36 169.88 15.69 42.02 3695.25 COCs/50BZ5 24.0 25.6/2.1 Y V-2 496.91 172.45 14.35 45.73 3844.81 Cone calorimetric test (CCT) analysis could simulate the real combustion situation according to the oxygen consumption, and analyze the combustion behavior of materials reflecting the real combustion situation of materials. The heat release rate (HRR), mass loss (MLR) and total heat release rate (THR) of the COC materials during combustion are shown in Fig. 6 . HRR is used to assess fire intensity and spread rate, and effective fire retardant systems often have low HRR values. Unlike the HRR behavior of neat COC, the HRR curves of all composites with IFR additives exhibit a special "M" behavior, which is resulted from the rupture of the carbon layer formation in the early stage leads to the rapid release of heat in the second stage. The beginning time of HRR in COCs/25BZ5 and COCs/50BZ5 materials increased dramatically due to the catalytic action in the decomposition of the base material. Compared with neat COC, the heat release time of all composites dramatically increased, which greatly reduces the fire risk of the material. Peak heat release rate (pHRR) can be obtained from the heat release rate curve (Fig. 6 a, Table 2 ). The pHRR value decreased from 1368.71 kW/m 2 for neat COC to 331.61 kW/m 2 for COCs/25BZ5, 75% lower than that for neat COC. The mass variation can be used to confirm the decomposition of COCs/25BZ5 and COCs/50BZ5, as shown in Fig. 6 b. When 1wt% ZSM-5 was added as IFR synergist, the THR of the material started to reduce from 152.95 MJ/m 2 of pure COC to 127.68 MJ/m 2 . HRR and MLR of all BZ5-containing COC samples were lower than that of neat COC. 3.4 Analysis of char residue In order to further understand the changes of the composite materials during the CCT test, SEM analysis was conducted on the carbon residue for COC composite, as shown in Fig. 7 . Figure 7 a 1 -d 1 and a 2 -d 2 are the side and front images of the carbon residue after the CCT test, respectively. From the SEM observation, the front photos of COCs and COCs/25BZ5 composites exhibit a smooth and completed carbon residue without apparently cracks inside. In addition, the height of the residual carbon is higher than that of neat indicating higher the expansion of IFR additive. As shown in Fig. 7 , the microscopic carbon layer of COCs composite material is more broken and has poor integrity, while the microscopic carbon layer of the composite material with BZ5 as a synergist is more continuous and dense, which indicates that the addition of BZ5 has a positive influence on the formation of carbon layer, making the microscopic carbon layer completed and dense during the formation. In order to analyze the chemical structure of the carbon residue, infrared analysis was performed on the carbon residue after cone calorimetric test, as shown in Fig. 8 . The characteristic peaks at 1750 cm − 1 , 1607 cm − 1 , 1132 cm − 1 and 998 cm − 1 correspond to C = O, C = C bond, C-O-C and P-O-C in the structure of aromatic compounds, respectively [ 22 , 23 ]. This indicates that APP is decomposed into phosphoric acid, pyrophosphate or polyphosphate at high temperature and cross-linked with PER, while small olefin molecules generated by pyrolysis are produced into aromatic compounds under the catalysis of ZSM-5 and BZ5 [ 24 ]. This cross-linked carbon layer can effectively slow down the transfer of heat and combustible materials between the gas phase and the condensed phase, thus inhibiting the combustion reaction of the substrate. The characteristic peak at 752 cm − 1 corresponds to the stretching vibration of Si-O in ZSM-5 molecular sieve [ 25 ], which indicates that ZSM-5 molecular sieve is finally embedded in the carbon layer structure, which is conducive to improving the toughness of the carbon layer. The weak absorption peak at 1403 cm − 1 corresponds to B-O-C[ 26 ], indicating that boric acid loaded on ZSM-5 molecular siolites also chemically reacted with adsorbed flame retardants. 3.5 Flame-retardant mechanism In order to explore the synergistic mechanism between BZ5 acid strength and acid content and IFR, and whether the synergistic effect is related to the acid site strength of BZ5, NH3-TPD tests were conducted on ZSM-5 and BZ5. It can be observed from Fig. 9 that each ammonia desorption curve has two peaks, among which the peak at 150–400 ℃ belongs to the weak acid acidic site of ammonia desorption, while the peak at 400–600 ℃ corresponds to the strong acid acidic site of ammonia desorption [ 27 ]. All BZ5 samples showed an increase in acid content compared to ZSM-5. Among them, 5BZ5 and 10BZ5 had only weak acid sites but no strong acid sites, indicating that a small amount of boric acid modification introduced a new weak acid site to ZSM-5, and covered or eliminated the strong acid site [ 20 ]. When more boric acid was used to modify ZSM-5, the acidity concentration of the weak acid site of BZ5 sample gradually increased from 15BZ5, and the strong acid site reappeared and strengthened. From the point of view of corresponding temperature of acid site, the corresponding temperature of weak acid acidic site of BZ5 sample first increased and then decreased with the increase of boric acid modification amount, and the highest temperature was 299.2℃ of 20BZ5 sample. It is worth noting that 25BZ5 corresponds to the weak acid acidic site temperature of 273.2℃, which is consistent with the initial decomposition temperature of APP, which may be related to the better flame retardant performance of COCs/25BZ5 composite. In addition, 50BZ5 has the most acidic sites, but the flame retardant performance is not improved, which indicates that the synergistic effect of molecular sieve and IFR is not determined by the amount of acid in the molecular sieve, but may be more related to the temperature corresponding to the acidic site. 4. Conclusions By modifying ZSM-5 with different boric acid content, a series of BZ5 supported by different boric acid content were obtained, and then COC flame retardant composites were prepared with IFR and BZ5. The surface morphology, distribution of flame retardants, flame retardancy and morphology and structure of carbon residue of the composite were studied. Characteristic elements were used in EDS tests to determine the uniform dispersion of APP, PER and BZ5 in the composite. In the LOI test, with the loading of boric acid of BZ5, the LOI value of the composite material increases first and then decreases, reaching the highest 28.5% of COCs/25BZ5 composite material, reaching the inflammability level. In CCT, the PHRR, THR and TSR of composites with BZ5 as synergist increased compared with that with unmodified ZSM-5, except for COCs/25BZ5 composites, which indicated that boric acid modification with appropriate content was helpful to improve the flame retardant property. The microscopic morphology and chemical structure of carbon residue after CCT test were studied by SEM and FTIR. The results show that BZ5 helps to form continuous and dense microscopic carbon residue structure and enhance the toughness of carbon layer by catalytic esterification crosslinking and catalytic pyrolysis of small olefin molecules to generate aromatic compounds. NH3-TPD showed the acidic sites and concentrations of different BZ5, indicating that the synergistic effect of BZ5 and IFR may be related to the corresponding temperature of the weak acid acidic site of BZ5. Declarations Acknowledgements The authors thank Natural Science Foundation of China (52303041, U22A20144), Natural Science Foundation of Ningxia (2023AAC03105) and the Research Project of the Ningxia Education Department for there help during this research. Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. References Sereni J G R (2016). "Reference module in materials science and materials engineering." Khanarian G (2001). "Optical properties of cyclic olefin copolymers." Optical Engineering 40(6).https://doi.org/10.1117/1.1369411 Nunes P S, Ohlsson, P D,Kutter, O O P (2010). 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3915796","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":275734412,"identity":"ca32eb11-f392-4587-8631-cd215f438fc3","order_by":0,"name":"Xiaokun Zhai","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xiaokun","middleName":"","lastName":"Zhai","suffix":""},{"id":275734413,"identity":"b93fc69d-0365-49bb-992f-f272a893edb8","order_by":1,"name":"Jiajia Gu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Jiajia","middleName":"","lastName":"Gu","suffix":""},{"id":275734414,"identity":"f7ec4589-8acf-439c-89c1-a7cfcc4b3e23","order_by":2,"name":"Qin Ma","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Qin","middleName":"","lastName":"Ma","suffix":""},{"id":275734415,"identity":"3a6364f5-043b-4c46-bcc4-4e0dada7f911","order_by":3,"name":"Yuwei Jin","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yuwei","middleName":"","lastName":"Jin","suffix":""},{"id":275734416,"identity":"f8d35385-3954-477f-b3dc-81c88bf5155d","order_by":4,"name":"Ruiyan Zhang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9klEQVRIiWNgGAWjYFACxgYwZQAiPjAg2MRpYZxBnBYGhDJmHmK0mM9IbpP4uYPB3pz97OHXtjsOJzawN2+TYKi5g1OLzI3ENsneMwzMlj15ada5Z9ISG3iOlUkwHHuGU4uERGKbBG8bA5vBgRwz49w2m8QGiRwzCcaGw3i1SP5tY+AxOP/GzNiyTSKxQf4NYS3SQFskDG7kGD9mBNvCQ0ALz8Nma9k2CQODG2/MGHvb0ozbeNKKLRKO4dHCnv7w5ts2G3uD8znGH362HZbtZz+88caHGtxagIBFAqgTxGCDkCAiAZ8GYAR+QGeMglEwCkbBKEABAOBPTeTBrDYdAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-0561-1025","institution":"Ningxia University; University of Toronto","correspondingAuthor":true,"prefix":"","firstName":"Ruiyan","middleName":"","lastName":"Zhang","suffix":""},{"id":275734417,"identity":"4a0ae5bf-e294-45f1-8dc7-b2660cf265ee","order_by":5,"name":"Faliang Luo","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Faliang","middleName":"","lastName":"Luo","suffix":""}],"badges":[],"createdAt":"2024-02-01 03:09:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3915796/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3915796/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10965-024-04090-5","type":"published","date":"2024-09-19T15:58:04+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":52006726,"identity":"339b79a7-3d3c-4927-84a5-1656f2a989b6","added_by":"auto","created_at":"2024-03-05 09:21:18","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":16790,"visible":true,"origin":"","legend":"\u003cp\u003eThe structure of E/NB copolymer\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/2a62cdfe2b206f9981991e7b.png"},{"id":52006729,"identity":"42b77e32-27de-493d-8cc9-6d7b7de50629","added_by":"auto","created_at":"2024-03-05 09:21:18","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":69381,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of the synthetic route of BZ5\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/5e11997c087e904fc3efb903.png"},{"id":52006725,"identity":"a4abda3d-166d-42ec-ac6f-380b9b5c62b0","added_by":"auto","created_at":"2024-03-05 09:21:18","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":483850,"visible":true,"origin":"","legend":"\u003cp\u003eSEM (a) of 25BZ5 and its element distribution (b) (c) (d)\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/ec199af0b7ee36a8db9917b7.png"},{"id":52006728,"identity":"c3b05823-68b9-47b2-878a-cdffaafe21ac","added_by":"auto","created_at":"2024-03-05 09:21:18","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":144908,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of ZSM-5, 5BZ5, 10BZ5, 15BZ5, 20BZ5, 25BZ5, 30BZ5, and 50BZ5 (a) locally amplified FTIR spectra (b) XPS spectra (c) and B1s spectra of 5BZ5, 10BZ5, 15BZ5, 20BZ5, 25BZ5, 30BZ5, and 50BZ5\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/aebace44f5b7f53d0bc48d84.png"},{"id":52007028,"identity":"d0277a8c-4627-4909-b651-b14f4dca4379","added_by":"auto","created_at":"2024-03-05 09:29:18","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":484704,"visible":true,"origin":"","legend":"\u003cp\u003eSEM of COCs/25BZ5 (a) and its element distribution (b) (c) (d)\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/23b9da9fd5548c63ef68f48d.png"},{"id":52006731,"identity":"66addaad-05fd-4ada-a054-99dcbb368cf6","added_by":"auto","created_at":"2024-03-05 09:21:18","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":197604,"visible":true,"origin":"","legend":"\u003cp\u003eHRR (a), Mass (b),TSR (c) and THR(d) of COC and its composites\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/ecb127d5f59d0ea09a72bfe5.png"},{"id":52007029,"identity":"98f3e6a2-8c00-4ee0-a025-8ac3b6e8e0e8","added_by":"auto","created_at":"2024-03-05 09:29:18","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":381430,"visible":true,"origin":"","legend":"\u003cp\u003eChar residue side, front and SEM photographs of COCs (a), COCs/5BZ5 (b), COCs/25BZ5 (c) and COCs/50BZ5 (d)\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/35be8b7816dc9766534ad1a5.png"},{"id":52006730,"identity":"453f620c-45cf-42be-a099-165f5f3899da","added_by":"auto","created_at":"2024-03-05 09:21:18","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":116735,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of char residue for COCs, COCs/ZSM-5, COCs/5BZ5, COCs/25BZ5 and COCs/50BZ5\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/e36ba8e1eaaaa708832a8b4a.png"},{"id":52006732,"identity":"35d8a184-9ece-41c0-b536-b14063f415ae","added_by":"auto","created_at":"2024-03-05 09:21:18","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":74511,"visible":true,"origin":"","legend":"\u003cp\u003eNH\u003csub\u003e3\u003c/sub\u003e-TPD of ZSM-5, 5BZ5, 10BZ5, 15BZ5, 20BZ5, 25BZ5, 30BZ5, and 50BZ5\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/e6412017087ea104ce4d6244.png"},{"id":65104118,"identity":"4a0cfa0e-934c-4207-910e-fffeb32414a4","added_by":"auto","created_at":"2024-09-23 16:11:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2404236,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3915796/v1/3093abe9-fe45-4b87-96b4-834fbd77693a.pdf"}],"financialInterests":"","formattedTitle":"The Flame Retardant Cyclic Olefin Copolymer Composites with Boric Acid Modified ZSM-5 Synergists","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eCyclic olefin copolymer (COC) is a kind of high-valued thermoplastic plastic composed of cyclic olefin and α-olefin portion [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. At present, most of the COC structures are ethylene/norbornene (E/NB) copolymers. Different from traditional linear polyolefin, COCs have excellent optical properties with higher transparency, and they exhibit higher glass transition temperature (T\u003csub\u003eg\u003c/sub\u003e), excellent moisture resistance, chemical stability, high biocompatibility and strong dielectric electrical characteristics, etc., therefore they are widely used in optical devices, capacitor films and medicine, packaging fields [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] In particular, the COC performances depend on their NB content, and the higher NB content, the higher T\u003csub\u003eg\u003c/sub\u003e and thermal deformation temperature [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Recently, Zhang et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] produced COC foam with excellent thermal insulated performance, which show great potential in building fields.\u003c/p\u003e \u003cp\u003eHowever, COCs are easy to be ignited by external fire sources due to COC macromolecular chain with carbon and hydrogen elements. When exposed to combustion, COC could release large amount of heat, smoke and even toxic gases, and result in the concern of casualties and property damage. The shortage of high flammability limits the application of COC materials in many important fields, therefore it is urgent and critical to improve COC flame retardant performance.\u003c/p\u003e \u003cp\u003eAt present, there are two ways to improve flame retardant performance, additive type and reactive type. Among all added flame retardants, halogen flame retardants present the advantages of high flame retardancy efficiency and without compromising mechanical properties. But halogen flame retardancy will release burned and toxic smoke leading into serious damage to the environment and human health [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Nowadays, the flame retardant products are required to show green and environmental protection. The intumescent flame retardant (IFR) with low smoke, low toxicity and high flame retardant efficiency has attracted more attention [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe IFR could delay further combustion and fire spread due to the formation of carbonized layer. According to the fire tetrahedral theory, heat, fuel, oxygen and chain reaction are four key elements for flame combustion, and thus combustion will be prevented from one or more elements separation. IFRs effectively protect the polymer from further combustion by forming carbonized layer on the surface, and prevent the oxygen diffusion and inhibit the mass transfer of combustible gas, and thus delay the degradation of the polymer and reduce smoke generation [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Moreover, synergist addition could improve the flame-retardant efficiency without attenuating physical and chemical performance.\u003c/p\u003e \u003cp\u003eSynergistic effect in flame retardancy is defined as two or more components combined performance is greater than that the sum of each component individual used. The common synergists of IFR includes metal oxides [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], organic montmorillonite [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], sepiolite [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] and zeolite molecular sieve [\u003cspan additionalcitationids=\"CR17\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. \u003cem\u003eBernardes\u003c/em\u003e at al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] found that H-ZSM-5 could act as catalyzer to cause the reaction between ammonium polyphosphate (APP) and pentaerythritol (PER), and thus the high acid center concentration is conductive to the formation of expansion precursors. \u003cem\u003eWu\u003c/em\u003e at al. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] studied the effect of boron modification on the acidity of ZSM-5, and the results showed that with the increase of boron content, the acid content of the weak acid site of the molecular sieve increased after boron modification.\u003c/p\u003e \u003cp\u003eHerein, we utilize ZSM-5 with various boric acid content as IFR synergistic agents to improve COC flame retardant performance. APP and PER were incorporated to develop COC composite. The boric acid modification was characterized by SEM with EDS scanning. And boric acid contents were analyzed by XPS and FTIR. The subsequent flame-retardant performance of COC composites were characterized by imiting oxygen index (LOI), vertical burning (UL-94) and cone calorimeter test (CCT). The results showed that boron modified ZSM-5 is an efficient IFR synergistic agent, which can improve the flame retardancy of COC composites.\u003c/p\u003e"},{"header":"2. Experimental Section","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Materials\u003c/h2\u003e \u003cp\u003eCOC (CAS:26007-43-2) was derived from TOPAS Advanced Polymers GmbH. ZSM-5 (SiO2/Al2O3\u0026thinsp;=\u0026thinsp;25) employed in this investigation was purchased from Nankai University Catalyst Co., Ltd. Boric acid (H\u003csub\u003e3\u003c/sub\u003eBO\u003csub\u003e3\u003c/sub\u003e, CAS:10043-35-3) and pentaerythritol (PER, CAS:115-77-5) were procured from Sinophosphate Chemical Reagent Co., Ltd. Ammonium polyphosphate (APP, CAS:68333-79-9) was obtained from Hangzhou Jelsi Flame Retardant Chemical Co., Ltd.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Preparation of B modified ZSM-5 (BZ5)\u003c/h2\u003e \u003cp\u003eFirstly, 15 g of ZSM-5 was added into 100 mL of deionized water, and then evenly stirred into the ultrasonic instrument, and the power was set to 50%. After 10 minutes of ultrasonication 0.789 g of H\u003csub\u003e3\u003c/sub\u003eBO\u003csub\u003e3\u003c/sub\u003e was added, and then ultrasound for 30 min. After centrifugation and overnight drying at 110 ℃, the molecular sieve sample obtained was recorded as 5BZ5. The rest remained unchanged, and the samples obtained by changing the addition amount of B(OH)3 to 1.667 g, 2.647 g, 3.750g, 5.000g, 6.429g and 15.000g were recorded as 10BZ5, 15BZ5, 20BZ5, 25BZ5, 30BZ5 and 50BZ5, respectively.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Fabrication of COC and COC composites\u003c/h2\u003e \u003cp\u003eFirstly, COC was vacuum-dried at 50 \u0026deg; C for 12 hours, and APP, PER, ZSM-5 and a series of BZ5 samples were dried under the vacuum at 80\u0026deg;C for 12 hours. PLA and PLA composites were fabricated via a twin-screw extruder (SJZS-10 A, China) in the temperature ranged from 185\u0026deg;C to 200\u0026deg;C with a screw speed of 30 rpm. The formula composition and labeling of PLA and PLA composites are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComposition of COC and composites\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"10\" nameend=\"c11\" namest=\"c2\"\u003e \u003cp\u003eComposition (wt.%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCOC\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAPP: PER\u003c/p\u003e \u003cp\u003e(3:1)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eZSM-5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5BZ5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10BZ5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e15BZ5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e20BZ5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e25BZ5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e30BZ5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003e50BZ5\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/ZSM-5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/5BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/10BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/15BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/20BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/25BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/30BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/50BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Characterizations\u003c/h2\u003e \u003cp\u003eFourier transform infrared spectra (FTIR) (Spectrum Two, Perkin Elmer Instruments Co., Ltd., USA) were performed within the wavenumber range of 4000-400cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e by Attenuated Total Reflectance (ATR) technique at room temperature.\u003c/p\u003e \u003cp\u003eX-ray photoelectron spectrometer (XPS) (AXIS SUPRA+, Shimadzu Corporation Co., Ltd., Japan) was used to perform elemental analysis of B/Z5.\u003c/p\u003e \u003cp\u003eThe fire behavior for all samples were evaluated by limiting oxygen index (LOI), vertical burning (UL-94) and cone calorimeter test (CCT). The LOI was tested with a Digital Oxygen Index Tester (5801A, Suzhou Yangyi Vouch Testing Technology Co., Ltd., China) with dimensions of 130 \u0026times; 6.5 \u0026times; 3 mm\u003csup\u003e3\u003c/sup\u003e according to ASTM D2863-97. The UL-94 test was performed on a Horizontal-vertical Burning Tester (5402, Suzhou Yangyi Vouch Testing Technology Co., Ltd., China) with the dimension of 130 \u0026times; 13 \u0026times; 3 mm\u003csup\u003e3\u003c/sup\u003e according to ASTM D3801. The CCT was carried out on cone calorimeter (6810, Suzhou Yangyi Vouch Testing Technology Co., Ltd., China) with dimensions of 100 \u0026times; 100 \u0026times; 3 mm\u003csup\u003e3\u003c/sup\u003e according to ISO 5660 with a heat flux of 35 kW/m\u003csup\u003e2\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eX-ray diffraction (XRD) was carried out using a powder diffractometer (D8 ADVANCEA25, Bruker AXS Co., Ltd., Germany) at Cu K\u003csub\u003eα\u003c/sub\u003e radiation with the wavelength of 1.54 \u0026Aring; (λ\u0026thinsp;=\u0026thinsp;1.54 \u0026Aring;) at room temperature. All the samples were dried in vacuum at 130\u0026deg;C for two hours before XRD test to remove moisture.\u003c/p\u003e \u003cp\u003eMorphology was observed by Scanning Electron Microscopy (SEM) (ZEISS EVO18, Carl Zeiss AG Co., Ltd., Germany) equipped with energy dispersive X-ray spectroscopy (EDS) at 15.00 kV.\u003c/p\u003e \u003cp\u003eTo investigate the thermal stability of samples, thermogravimetric analysis (TGA) was performed on TA Instrument (Pyris 1, Perkin Elmer Instruments Co., Ltd., USA), all of the specimens were heated from 50 to 790\u0026deg;C at a heating rate of 10\u0026deg;C/min under N\u003csub\u003e2\u003c/sub\u003e atmosphere with flow rate of 50 mL/min.\u003c/p\u003e \u003cp\u003eTemperature programmed desorption of NH\u003csub\u003e3\u003c/sub\u003e (NH\u003csub\u003e3\u003c/sub\u003e-TPD) was tested on a chemisorbed instrument (Model: AutoChem1Ⅱ2920, USA). All samples were heated at a heating rate of 10 ℃/min to 300 ℃ under a helium flow rate of 30 ml/min, pre-treated for 1 hour, then cooled to 120 ℃, and a mixture of NH\u003csub\u003e3\u003c/sub\u003e/He (volume ratio\u0026thinsp;=\u0026thinsp;15/85) was introduced for adsorption. For gas desorption, after helium purge, all samples were heated from 120 \u0026deg; C to 650 \u0026deg; C at a rate of 10 \u0026deg; C /min.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and discussions","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Characterization of boric acid modified ZSM-5 samples\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn order to observe the boric acid modified ZSM-5 molecular sieve, ZSM-5 partilces were observed by SEM with EDS analysis. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea, the boric acid modified ZSM-5 have particles of ~\u0026thinsp;2 \u0026micro;m, which is similar to unmodified ZSM-5 molecular sieve. It is indicated that boric acid modification could not change microscopic morphology of ZSM-5. According to EDS analysis, the boron, aluminum and silicon elements are uniformly dispersed on ZSM-5 molecular sieve.\u003c/p\u003e \u003cp\u003eIn order to analyze the boric acid content on ZSM-5 molecular sieve, both FTIR and XPS tests were performed on ZSM-5 and results were shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. The full-reflection infrared spectra of ZSM-5 with and without boric acid modification was shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea. The strong absorption peak at 1393 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e correlated to the B-O interaction [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], and B-O interaction gradually increased with increasement of absorption peak intensity (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). In order to further quantitatively analyze boric acid content on ZSM-5, boric acid modified ZSM-5 with various content were characterized by XPS spectra, which is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed (b), the peak at 193.4eV related to B1s can be clearly observed. One can find that the peak intensity of spectrum increased, indicated that the boric acid content gradually increased. Accordingly, the loading of boric acid were 2.17%, 7.48%, 7.11%, 8.95%, 9.23%, 12.79%, 16.64%, respectively.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Distribution of flame retardants and BZ5\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo observe the dispersion of modified ZSM particles in the COCs/25BZ5 composite, scanning electron microscope with EDS analysis was carried out and results are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. The distribution of corresponding additive particles can be seen from each element, where phosphorus element (P) is the characteristic element of APP, oxygen element (O) is the characteristic element of PER, and silicon (Si) corresponding to ZSM-5 molecular sieve. It can be seen that the particles are uniformly dispersed in the COCs/25BZ5 composite.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e3.3 Flame retardancy of COC and COC composites\u003c/h2\u003e \u003cp\u003eThe LOI and UL-94 were used to study the flame retardancy of COC and its composites. The detailed data are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The LOI of neat COC was only 15.3%, and it does not have grade according to UL-94 test. After adding the IFR in COC composite, the LOI value gradually increase to 20.5%, and LOI value of the COC slightly increased to 23.8% with further incorporation of unmodified ZSM-5, and UL-94 level reached to V-2 level. With further adding boric acid modified ZSM-5 from 2.2% (5BZ5 sample) to 16.6% (25BZ5 sample), the LOI value first increased to 28.5% and then decreased down 24%. It indicated that there was an optimized boric acid content modification on ZSM-5. In the UL-94 test, although the ignition time of the material was improved, the COCs/25BZ5 sample did not reach V-0 level due to the obvious droplet phenomenon of the material, which always ignited the cotton pad.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eLOI, UL-94 and CCT data of COC and COC composites\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSample name\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eLOI (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eUL-94\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePHRR\u003c/p\u003e \u003cp\u003e(kW/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTHR\u003c/p\u003e \u003cp\u003e(MJ/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eChar\u003c/p\u003e \u003cp\u003eyield\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAv-EHC\u003c/p\u003e \u003cp\u003e(MJ/kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTSR\u003c/p\u003e \u003cp\u003e(m\u003csup\u003e2\u003c/sup\u003e/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAFTa(s)\u003c/p\u003e \u003cp\u003et1/t2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003edripping\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003erating\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21.8/6.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eN.R.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1368.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e152.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e32.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e2443.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.8 /9.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eV-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e344.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e131.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e15.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e33.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e2801.23\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/ZSM-5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e23.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.0/13.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eV-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e368.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e127.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e15.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e33.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e2372.78\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/5BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25.7/11.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eN.R.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e471.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e173.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e16.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e41.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e3957.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/10BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e23.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19.3/3.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eV-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e405.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e183.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e18.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e47.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e3242.06\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/15BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e26.1/4.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eN.R.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e436.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e176.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e17.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e48.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e3639.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/20BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.2 /12.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eV-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e374.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e174.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e19.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e36.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e3717.74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/25BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e28.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.5/9.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eV-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e331.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e165.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e16.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e38.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e3733.48\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/30BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19.3/5.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eV-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e412.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e169.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e15.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e42.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e3695.25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOCs/50BZ5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25.6/2.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eV-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e496.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e172.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e14.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e45.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e3844.81\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eCone calorimetric test (CCT) analysis could simulate the real combustion situation according to the oxygen consumption, and analyze the combustion behavior of materials reflecting the real combustion situation of materials. The heat release rate (HRR), mass loss (MLR) and total heat release rate (THR) of the COC materials during combustion are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e. HRR is used to assess fire intensity and spread rate, and effective fire retardant systems often have low HRR values. Unlike the HRR behavior of neat COC, the HRR curves of all composites with IFR additives exhibit a special \"M\" behavior, which is resulted from the rupture of the carbon layer formation in the early stage leads to the rapid release of heat in the second stage. The beginning time of HRR in COCs/25BZ5 and COCs/50BZ5 materials increased dramatically due to the catalytic action in the decomposition of the base material. Compared with neat COC, the heat release time of all composites dramatically increased, which greatly reduces the fire risk of the material. Peak heat release rate (pHRR) can be obtained from the heat release rate curve (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ea, Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The pHRR value decreased from 1368.71 kW/m\u003csup\u003e2\u003c/sup\u003e for neat COC to 331.61 kW/m\u003csup\u003e2\u003c/sup\u003e for COCs/25BZ5, 75% lower than that for neat COC. The mass variation can be used to confirm the decomposition of COCs/25BZ5 and COCs/50BZ5, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eb. When 1wt% ZSM-5 was added as IFR synergist, the THR of the material started to reduce from 152.95 MJ/m\u003csup\u003e2\u003c/sup\u003e of pure COC to 127.68 MJ/m\u003csup\u003e2\u003c/sup\u003e. HRR and MLR of all BZ5-containing COC samples were lower than that of neat COC.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.4 Analysis of char residue\u003c/h2\u003e \u003cp\u003eIn order to further understand the changes of the composite materials during the CCT test, SEM analysis was conducted on the carbon residue for COC composite, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e. Figure\u0026nbsp;7 a\u003csub\u003e1\u003c/sub\u003e-d\u003csub\u003e1\u003c/sub\u003e and a\u003csub\u003e2\u003c/sub\u003e-d\u003csub\u003e2\u003c/sub\u003e are the side and front images of the carbon residue after the CCT test, respectively. From the SEM observation, the front photos of COCs and COCs/25BZ5 composites exhibit a smooth and completed carbon residue without apparently cracks inside. In addition, the height of the residual carbon is higher than that of neat indicating higher the expansion of IFR additive. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e, the microscopic carbon layer of COCs composite material is more broken and has poor integrity, while the microscopic carbon layer of the composite material with BZ5 as a synergist is more continuous and dense, which indicates that the addition of BZ5 has a positive influence on the formation of carbon layer, making the microscopic carbon layer completed and dense during the formation.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn order to analyze the chemical structure of the carbon residue, infrared analysis was performed on the carbon residue after cone calorimetric test, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e. The characteristic peaks at 1750 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1607 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1132 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 998 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e correspond to C\u0026thinsp;=\u0026thinsp;O, C\u0026thinsp;=\u0026thinsp;C bond, C-O-C and P-O-C in the structure of aromatic compounds, respectively [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. This indicates that APP is decomposed into phosphoric acid, pyrophosphate or polyphosphate at high temperature and cross-linked with PER, while small olefin molecules generated by pyrolysis are produced into aromatic compounds under the catalysis of ZSM-5 and BZ5 [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. This cross-linked carbon layer can effectively slow down the transfer of heat and combustible materials between the gas phase and the condensed phase, thus inhibiting the combustion reaction of the substrate. The characteristic peak at 752 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e corresponds to the stretching vibration of Si-O in ZSM-5 molecular sieve [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e], which indicates that ZSM-5 molecular sieve is finally embedded in the carbon layer structure, which is conducive to improving the toughness of the carbon layer. The weak absorption peak at 1403 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e corresponds to B-O-C[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], indicating that boric acid loaded on ZSM-5 molecular siolites also chemically reacted with adsorbed flame retardants.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e3.5 Flame-retardant mechanism\u003c/h2\u003e \u003cp\u003eIn order to explore the synergistic mechanism between BZ5 acid strength and acid content and IFR, and whether the synergistic effect is related to the acid site strength of BZ5, NH3-TPD tests were conducted on ZSM-5 and BZ5. It can be observed from Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e that each ammonia desorption curve has two peaks, among which the peak at 150\u0026ndash;400 ℃ belongs to the weak acid acidic site of ammonia desorption, while the peak at 400\u0026ndash;600 ℃ corresponds to the strong acid acidic site of ammonia desorption [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. All BZ5 samples showed an increase in acid content compared to ZSM-5. Among them, 5BZ5 and 10BZ5 had only weak acid sites but no strong acid sites, indicating that a small amount of boric acid modification introduced a new weak acid site to ZSM-5, and covered or eliminated the strong acid site [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. When more boric acid was used to modify ZSM-5, the acidity concentration of the weak acid site of BZ5 sample gradually increased from 15BZ5, and the strong acid site reappeared and strengthened. From the point of view of corresponding temperature of acid site, the corresponding temperature of weak acid acidic site of BZ5 sample first increased and then decreased with the increase of boric acid modification amount, and the highest temperature was 299.2℃ of 20BZ5 sample. It is worth noting that 25BZ5 corresponds to the weak acid acidic site temperature of 273.2℃, which is consistent with the initial decomposition temperature of APP, which may be related to the better flame retardant performance of COCs/25BZ5 composite. In addition, 50BZ5 has the most acidic sites, but the flame retardant performance is not improved, which indicates that the synergistic effect of molecular sieve and IFR is not determined by the amount of acid in the molecular sieve, but may be more related to the temperature corresponding to the acidic site.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eBy modifying ZSM-5 with different boric acid content, a series of BZ5 supported by different boric acid content were obtained, and then COC flame retardant composites were prepared with IFR and BZ5. The surface morphology, distribution of flame retardants, flame retardancy and morphology and structure of carbon residue of the composite were studied.\u003c/p\u003e \u003cp\u003eCharacteristic elements were used in EDS tests to determine the uniform dispersion of APP, PER and BZ5 in the composite. In the LOI test, with the loading of boric acid of BZ5, the LOI value of the composite material increases first and then decreases, reaching the highest 28.5% of COCs/25BZ5 composite material, reaching the inflammability level. In CCT, the PHRR, THR and TSR of composites with BZ5 as synergist increased compared with that with unmodified ZSM-5, except for COCs/25BZ5 composites, which indicated that boric acid modification with appropriate content was helpful to improve the flame retardant property. The microscopic morphology and chemical structure of carbon residue after CCT test were studied by SEM and FTIR. The results show that BZ5 helps to form continuous and dense microscopic carbon residue structure and enhance the toughness of carbon layer by catalytic esterification crosslinking and catalytic pyrolysis of small olefin molecules to generate aromatic compounds. NH3-TPD showed the acidic sites and concentrations of different BZ5, indicating that the synergistic effect of BZ5 and IFR may be related to the corresponding temperature of the weak acid acidic site of BZ5.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003eThe authors thank Natural Science Foundation of China (52303041, U22A20144), Natural Science Foundation of Ningxia (2023AAC03105) and the Research Project of the Ningxia Education Department for there help during this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eSereni J G R (2016). \u0026quot;Reference module in materials science and materials engineering.\u0026quot;\u003c/li\u003e\n \u003cli\u003eKhanarian G (2001). \u0026quot;Optical properties of cyclic olefin copolymers.\u0026quot; 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However, it is challenging to improve COC flame retardant behavior due to macromolecular chain with carbon and hydrogen elements. Herein, we utilize boric acid modified ZSM-5 (BZ5) as synergist in order to achieve the intumescent flame retardant (IFR) COC composite. The surface morphology, distribution of flame retardants, flame retardancy and morphology and structure of carbon residue of the composite were studied by SEM, EDS, LOI, CCT and FTIR characterizations. With adding BZ5 as a synergist, the LOI value can reach up to 28.5%, which is much higher than that of 15.3% for neat COC. Char residue content increased from 0.97% to 19.7% with BZ5 as a synergist in the COC composite. According to SEM and FTIR results, dense microscopic carbon residue structure after boric acid modification. The study shows that the modification of boric acid with appropriate content can improve the flame retardancy of COC.\u003c/p\u003e","manuscriptTitle":"The Flame Retardant Cyclic Olefin Copolymer Composites with Boric Acid Modified ZSM-5 Synergists","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-05 09:21:13","doi":"10.21203/rs.3.rs-3915796/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2024-02-29T09:55:02+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-02-29T04:56:57+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Journal of Polymer Research","date":"2024-02-15T19:09:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-02-02T05:16:08+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Polymer Research","date":"2024-02-01T21:02:42+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-polymer-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jpol","sideBox":"Learn more about [Journal of Polymer Research](https://www.springer.com/journal/10965)","snPcode":"10965","submissionUrl":"https://www.editorialmanager.com/jpol/","title":"Journal of Polymer Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"a3e32d51-b415-4a56-80cf-76e75fd12126","owner":[],"postedDate":"March 5th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-09-23T16:05:32+00:00","versionOfRecord":{"articleIdentity":"rs-3915796","link":"https://doi.org/10.1007/s10965-024-04090-5","journal":{"identity":"journal-of-polymer-research","isVorOnly":false,"title":"Journal of Polymer Research"},"publishedOn":"2024-09-19 15:58:04","publishedOnDateReadable":"September 19th, 2024"},"versionCreatedAt":"2024-03-05 09:21:13","video":"","vorDoi":"10.1007/s10965-024-04090-5","vorDoiUrl":"https://doi.org/10.1007/s10965-024-04090-5","workflowStages":[]},"version":"v1","identity":"rs-3915796","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3915796","identity":"rs-3915796","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}