Mechanical, thermal properties and curing kinetics of liquid silicone rubber filled with cellulose nanocrystal

To prepare liquid silicone rubber (LSR)/cellulose nanocrystal (CNC) nanocomposite, 3-aminopropyltriethoxysilane (APTES) was used to modify the surface of CNC to improve the interfacial interaction between the hydrophilic CNC and the hydrophobic LSR. Fourier transform infrared spectroscopy and energy dispersive spectrometer results demonstrated that APTES modified CNC successfully. It was found that small amount of modified CNC (M-CNC) had better reinforcement than SiO2 in LSR nanocomposites, the tensile strength and the strain at break of LSR increased over 85% and 44% by adding 1.5 wt% M-CNC. However, DSC and rheology tests indicated that APTES modified CNC increased the curing temperature of LSR and limited the addition of CNC, which was attributed to poisoning of Pt catalyst by APTES. Furthermore, small amount of M-CNC improved the thermal stability of LSR, the TGA results showed that the 10% weight loss temperature (T10%) of LSR increased 56 °C with 1.0 wt% addition of M-CNC.