Highly stretchable or extremely soft silicone elastomers? One reaction to make them all - from easily available materials!

Abstract An easy curing reaction to prepare silicone elastomers is reported, in which a platinum catalyzed reaction of telechelic/multi-hydrosilane (Si-H) functional polydimethylsiloxane (PDMS) in the presence of oxygen and water leads to slow crosslinking. This curing chemistry allows versatile tailoring of elastomer properties, which exceed their intrinsic limitations. Both highly stretchable silicone elastomers and extremely soft silicone elastomers are prepared by creating highly entangled elastomers and bottle-brush elastomers from commercial precursor polymers, respectively. The highly stretchable elastomers can be uniaxially stretched to a maximum strain of 2800% and their areas can be biaxially extended 180-fold. The extremely soft silicone elastomers exhibit shear moduli of 1.2-7.4 kPa, depending on composition, values that are comparable to hydrogels and human soft tissues. The reported curing chemistry can be used to prepare a range of silicone elastomers with carefully tailored mechanical properties.