Grafting Nanocellulose With Diethylenetriaminepentaacetic Acid and Chitosan As Additive for Enhancing Recycled OCC Pulp Fibres

Abstract This paper is to develop a novel paper additive for effectively recycling old corrugated container (OCC) by functionalizing nanocellulose (NC) with diethylenetriaminepentaacetic acid (DTPA) and chitosan (CS), and investigate the reinforcing mechanisms and effect of the developed additive on the physical properties of recycled OCC pulp handsheets. The tensile, tear and bursting strength, whiteness, air permeability, tensile energy absorption of the recycled OCC handsheets are examined. Fourier transform infrared FTIR) spectroscopy, thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM) are used for the chemical and microstructure characterization of both NC based additives and recycled OCC pulp paper. The results show that the functional groups, such as carboxyl, amino and hydroxyl groups on the NC based additives, can combine with the hydroxyl groups on the recycled OCC fibres to generate chemical bonds, which increase the crosslinks between fibres as well as the bonding area, thus enhancing their tensile strength and improving their recycling rate. SEM shows that the paper with NC based additives had tighter inter-fibre bonds and smaller paper pore structure. Addition of 0.2% NC-DTPA-CS additive results in optimal properties of the recycled OCC paper with an increase by 32%, 188%, 19% and 35% of tensile strength, tearing degree, breaking resistance and air permeability respectively.