Solventless silicone hybrids based on polyhedral oligomeric silsesquioxane and hyperbranched polysiloxane for vacuum pressure impregnation process

A novel kind of solventless silicone hybrids (SSiH) containing branched poly(methylphenylvinylsiloxane) (PMPVSi), end‐capped hydrogen‐functionalized hyperbranched polysiloxane (EHFHPSi), and octavinyl‐polyhedral oligomeric silsesquioxane (OVPOS) was developed through a hydrosilylation reaction. Each of the three basic components was synthesized by harmless and recyclable methods. The new hybrids are considerably suitable for vacuum pressure impregnation process, and can serve as an excellent class C insulating material. The effect of differing stoichiometries of OVPOS and EHFHPSi on the performance of cured hybrids is discussed. Results show that SSiH hybrids possess excellent dielectric and thermal properties as well as low viscosity. The reduction in the dielectric constant and the improvement of thermal property of SSiH hybrids can be explained by the unique structure and morphology of hybrids resulting from the presence of OVPOS and EHFHPSi. The novel silicone hybrids exhibit great potential to be used for many cutting‐edge industries, especially the microelectronic and insulation fields. Copyright © 2010 John Wiley & Sons, Ltd.