Preparation of diamine-POSS/Ag hybrid microspheres and its application in epoxy resin

The synthesis of polyhedral oligomeric silsesquioxane (POSS) via hydrolytic co-condensation of phenyltriethoxysilane (PTES) and ã-aminopropyltrieth- oxysilane (APS) was presented in this paper. The microspheres with mean diameter of 1.83 ìm were precipitated from solvent phase through self-assembly when solvent phase was changed. After the reduction of hydrazine hydrate, POSS/ Ag hybrid microspheres were obtained based on the chelation of external amino-groups to silver ions. The hybrid microspheres modified epoxy resin was also studied in the work. The structure and particle size distribution of POSS, feature and silver content of the POSS/Ag core/shell microspheres, heat resistance, thermal conductivity and comprehensive mechanical properties of the epoxy resin modified by diamine-POSS/Ag were characterized by NMR, FTIR, SEM, Laser Particle Sizer, TGA and Flat Heat Conduction Coefficient, Universal Testing Machine. It was found that POSS was cage-like structures with two amino-groups, amino group content was 2.12 mmol/g and the silver conten was 47.96 %, respectively. When Ag addition reached 5 %, thermal conductivity of the modified epoxy resin has increased fourfold four times greater than pure, and the heat resistance increased by 35 °C. Moreover, the bending strength and impact strength of the modified resin were 127 MPa and 11.94 KJ/m², respectively, compared with pure epoxy resin, both of which have improved.