Characterization and properties of a novel organic-inorganic hybrid based on hyperbranched aliphatic polyester prepared via sol-gel process

A series of organic-inorganic hybrids, as a kind of composite material, were prepared based upon hyperbranched aliphatic polyester (Boltorn™ H20), which reacted with succinic anhydride and glycidoxy-propyltrimethoxysilane as a coupling agent, then condensed with pre-hydrolyzed product of tetraethoxysilane via a sol-gel process. Solid 29Si nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy were used to characterize the condensation degree and Si-2p core-level valence of the hybrids. Both the results have shown that the condensation degree of the hybrids increased with the addition of tetraethoxysilane. The morphological analysis performed by scanning electronic microscopy has shown that the silica particles dispersed homogeneously in the polymer matrix as nanoparticles with the size of 6-9 nm. The Tg of hybrids measured by differential scanning calorimetry increased with the increasing silica content, whereas the thermal stability showed not big different except for more residue formed at high silica content. The refractive indices and abrasion resistance of the composite materials increased with the increasing silica contents, as well as the baking temperature.