Abstract: This invention is directed to thiol containing compounds having no hydrolytically sensitive groupings which are useful as polymerization transfer agents or as curing agents in curable polymer systems containing polyenes and a free radical initiator. The thiol containing compounds are formed by reacting a polyol with an allylic halide to form a poly(unsaturated ether) whose double bonds are converted to thioesters by free radical catalyzed addition of SH groups from a thiolcarboxylic acid, e.g. thioacetic acid and the like. Hydrolysis of the thioester yields the desired thiol or polythiol derivative. Alternatively the poly(unsaturated ether) is reacted with H.sub.2 S to give the desired thiol or polythiol directly in a single step. The polythiols can be chain extended by any difunctional compound that reacts with the hydroxy groups on the polythiol.

Abstract: The novel urethane polythiols of this invention are prepared by reacting: (a) a mono-, di-, or trihydric polythiol with a polymeric isocyanate; or (b) a di- or trihydric polythiol with a diisocyanate.

Abstract: A urethane polythiol, which can be a dithiol, is prepared by reacting a hydroxypolythiol, which can be a dithiol, with an isocyanate such as phenyl isocyanate, toluene diisocyanate, and the like.

Abstract: A urethane polythiol, which can be a dithiol, is prepared by reacting a hydroxypolythiol, which can be dithiol, with an isocyanate such as a phenyl isocyanate, toluene diisocyanate, and the like.

Abstract: A urethane polythiol, which can be a dithiol, is prepared by reacting a hydroxypolythiol, which can be a dithiol, with an isocyanate such as phenyl isocyanate, toluene diisocyanate, and the like.