The Effect of Surface Modification of TiO2with Diblock Copolymers on the Properties of Epoxy Nanocomposites

The TiO2 nanoparticles were modified by diblock copolymers, poly(methyl methacrylate)-b-polystyrene (PMMA-b-PS), via reversible addition-fragmentation chain transfer (RAFT) polymerization, and the epoxy nanocomposites containing different TiO2 and with different contents were prepared. Subsequently, the effects of TiO2 content on the mechanical and thermal properties of nanocomposites were investigated. The results indicated that after grafting copolymers onto TiO2, the dispersion of TiO2 and interaction with epoxy matrix could be significantly increased, therefore, the mechanical properties of the nanocomposites were improved greatly. When the TiO2-PMMA-b-PS content was 1 wt%, the impact strength and flexural strength reached their the best, and increased up to 96% and 43%, respectively. Furthermore, the thermal stability of the nanocomposites was also distinctly improved.