Synthesis and modification of spherical SiO2 nanoparticles with different particle sizes and morphologies and their effects on the properties of thermoplastic polyurethane urea elastomers

摘要

Abstract A thermoplastic polyurethane urea (TPUU) elastomer with superior mechanical and thermal properties was recently reported from our group and synthesized by asymmetric aliphatic diisocyanate and diamine. In order to enhance its performance, this TPUU was further modified with spherical SiO2 nanoparticles in this work, and the influence of the size and morphology of spherical SiO2 nanoparticles on mechanical, thermal, and thermomechanical properties of TPUU was investigated. The results showed that spherical SiO2 nanoparticles could significantly improve the mechanical, thermal, and thermomechanical properties of TPUU, which increased, with the decrease of the particle size of SiO2 nanoparticles. Especially, compared with solid spherical SiO2 nanoparticles, TPUU nanocomposites filled with hollow spherical SiO2 (HSSiO2) particles showed abnormal but unique stress–strain behavior, and their elongations at break increased with the decrease of particle size of HSSiO2 nanoparticles.