Synergistic effects of silica nanoparticles and reactive compatibilizer on the compatibilization of polystyrene/polyamide 6 blends

This study examines the selective dispersion of nano-SiO 2 in polystyrene (PS) and polyamide 6 (PA6) blends. With the coupling assistance of 3-methacryloylpropyl trimethoxysilane (MPS), nano-SiO 2 surfaces are grafted with PS chains of different molecular weights (SiO 2 –MPS–PS) or reactive random copolymer of styrene (St) and 3-isopropenyl-α,α′-dimethylbenzene isocyanate (TMI) to produce SiO 2 –MPS–P(St–co–TMI). The isocyanate groups of the reactive copolymer can react with the terminal group of the PA6 to form a graft copolymer, which helps in controlling the location of nano-SiO 2 between the PS and PA6 phases. Field-emission scanning electron microscopy imaging combined with the rheological method was used to investigate the location and dispersion of nano-SiO 2 , as well as the morphology of the PS/PA6 blends, at low nano-SiO 2 loading. Compared with pristine SiO 2 , the modified SiO 2 with different chain lengths adjusted the PA6 phase with refined size and narrow size distribution because of the strong interaction with both phases. The SiO 2 –MPS–PS with appropriate length is the most effective. The use of nano-SiO 2 along with the reactive compatibilizer provides synergistic effects for improving the compatibilization of PS/PA6 blends. POLYM. ENG. SCI., 57:1301–1310, 2017. © 2017 Society of Plastics Engineers