Silicone graft copolymers with styrene, methylmethacrylate and chloroprene

摘要

We have reacted styrene, methylmethacrylate and chloroprene with siloxane polymers bearing thiol groups using a free radical initiator. One siloxane has a thiol group attached to each silicon atom, the second has thiol groups linked to about 5% of the silicons, and the third, the α,ω-polymer, has a thiol group at each end. At one extreme of the reaction conditions we used - low monomer concentration and high thiol concentration - the monomers were linked singly to the sulfur by the thiol-ene reaction, and at the other extreme, when the thiol group behaved as a chain transfer agent, many became attached to the sulfur atoms, so that graft copolymers formed. The turbidity of cast films and the presence of two glass transitions in the DSC traces will be examined as evidence for two phases in the solid states.