High impact poly(urethane urea) polysulfides

摘要

The present invention relates to a sulfur-containing polyureaurethane and a method of preparing the polyureaurethane. The sulfur-containing polyureaurethane has a refractive index of at least 1.57, an Abbe number of at least 32 and a density of less than 1.3 grams/cm3 when cured. The sulfur-containing polyureaurethane is prepared by the reaction of: (a) a sulfur-containing, isocyanate functional polyurethane prepolymer derived from: (i) a polyisocyanate; and (ii) a polythiol oligomer produced by the reaction of at least two or more different dienes with one or more dithiols and in certain embodiments at least one trifunctional or higher-functional polythiol; and (b) an amine-containing curing agent.