SYNTHESIS OF THE SILICA PARTICLES GRAFTED WITH POLY(IONIC LIQUID) AND ITS APPLICATION IN FOAMING OF POLYSTYRENE

摘要

Poly[2-(methacryloyloxy)ethyl]trimethylammonium tetrafluoroborate (P[MATMA][BF_4]), as a novel poly(ionic liquid) for the strong absorption of carbon dioxide (CO_2), is grafted to silica particles by using a surface-initiated atom transfer radical polymerization (ATRP). Silica particles modified by P[MATMA][BF_4] (SiO_2-P[MATMA][BF_4]) play as nucleating agents to produce polystyrene (PS) foams using supercritical CO_2 as a blowing agent. Compared with amino-functionalized silica particles (SiO_2-NH_2), SiO_2-P[MATMA][BF_4] exhibits higher heterogeneous nucleation efficiency in the foaming process. The morphology characterization indicates that PS/SiO_2-P[MATMA][BF_4] composite foams have higher cell density and smaller cell size than those of pure PS and PS/SiO_2-NH_2 composite foams.