Characterization of LLDPE/nano-SiO2 composites by solid-state dynamic mechanical spectroscopy

The dynamic mechanical properties of LLDPE/nano-SiO2 composites have been investigated by means of DMTA. The results showed that with the increase of nano-SiO2 content, the storage modulus E' and loss modulus E" of LLDPE composites filled with untreated SiO2 and aminetriethoxysilane treated SiO2 increased and the a transition peaks of the composites shifted to lower temperature. The storage modulus E' of LLDPE composites filled with aminetriethoxysilane treated SiO2 was lower than the corresponding value for LLDPE/untreated SiO2 composites at lower temperatures and this trend was reversed as the temperature increased to room temperature. The introduction of macromolecular compatibilizer into the former system led to the shifting of the a transition peak of the composites to lower temperature and obvious modulus enhancement at -50 to 110 degreesC. When SiO2 was treated with vinytrimethoxysilane, E' and V of the resulting composites were both higher than the corresponding values for LLDPE composites with aminetriethoxysilane treated-SiO2. The interaction between the matrix and the fillers had a remarkable effect on the dynamic mechanical properties of the composites. (C) 2003 Elsevier Ltd. All rights reserved.