Studies on the synthesis and reaction of silicone oxirane dendrimer and their thermal and rheological properties

Abstract

A series of silicone core dendrimers bearing SiH terminal group was synthesized by the reaction of tetraethoxysilane and diorganochlorosilane in high yields, which on reacting with allylglycidylether in presence of Speier’s catalyst yielded oxirane terminated dendrimers. These dendrimers were characterized using physico-chemical techniques viz; elemental analysis, Fourier transforms infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (1H NMR spectroscopy). Molecular weight was determined by vapour pressure osmometry (VPO). The rheological studies were performed to study the curing behavior of oxirane dendrimer with triethylenetetraamine. Thermal properties of cured dendrimers were evaluated using thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). Change in thermal properties of epoxy resin (LY556) on addition of dendrimers was also studied by TGA and DSC.