Synthesis and characterization of organic-inorganic hybrids based on epoxy resin and 3-glycidyloxypropyltrimethoxysilane

Organic-inorganic hybrid materials based on diglycidyl ether of bisphenol A (DGEBA) and 3-glycidyloxypropyltrimethoxysilane (GLYMO) were prepared, using a poly(oxypropylene) diamine Jeffamine D230 as a curing agent. Materials were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), infrared spectroscopy, swelling in tetrahydrofurane (THF), and Soxhlet extraction in THF. A dependence of the final conversion of epoxy groups and the final degree of organic phase crosslinking on inorganic phase content was found. The inorganic phase presents a steric hindrance to full crosslinking of epoxy groups. It also immobilizes the organic chains and improves the temperature stability of hybrid materials. Products of GLYMO hydrolysis together with unreacted organic molecules lower the glass transition temperature of hybrid materials. (C) 2004 Wiley Periodicals, Inc.