Polyurethane composites based on silsesquioxane derivatives of different structures

Abstract

A series of siloxane–silsesquioxane resins with Q8 structures, as network nodes containing reactive Si–H groups in the siloxane backbone, connecting silsesquioxane moieties, were prepared in a hydrolytic condensation process and successfully functionalized by hydrosilylation of allyl alcohol. The proposed material being an alternative to the well-defined silsesquioxanes has been characterized and used for preparation of a series of polyurethane (PU)-based composites by simple reaction of 3-hydroxypropyl groups of siloxane–silsesquioxane resin with 1,6-diisocyanatohexane and subsequently with 1,6-hexanediol to get polyurethane composite. A series of composites based on PU and octakis(3-hydroxypropyldimethylsiloxy)octasilsesquioxane were prepared in the same manner to investigate the influence of the filler amount (1, 3 or 5%) and its structure on thermal properties of the obtained materials.