Oligomeric Silsesquioxane–Siloxane Modifiers for Polymer Dental Compounds

Abstract

Methacrylate-containing silsesquioxane–siloxane oligomers with Mw = (2–20) × 103 determined by gel permeation chromatography (GPC) are synthesized by acidohydrolytic copolycondensation of γ‑methacryloxypropyltrimethoxysilane and diorganodialkoxysilanes. According to the data of 29Si NMR spectro-scopy, the molecules of these oligomers contain silsesquioxane units (RSiO1.5)n, where R is a γ-methacryloxypropyl radical, and mixed cyclic structures of the (RSiO1.5)m(R'R''SiO)p type, where R' is CH3 and R'' is CH3 or C6H5, with linear diorganosiloxane fragments added to them. The introduction of 6 wt % silsesquioxane–siloxane oligomers into a filled base dental compound based on a mixture of bismethacrylates increases its mechanical characteristics by more than a factor of 1.25–1.75 with a simultaneous substantial decrease in the polymerization shrinkage, water uptake, and water solubility.