Nitroxide-controlled free radical polymerization of p-tert-butoxystyrene. Kinetics and applications

摘要

The free radical polymerization of p-tert-butoxystyrene (BOS) in the bulk at 125 degrees C "initiated" with the adduct of 2-benzoyloxy-1-phenylethyl and TEMPO (BS-TEMPO) was found to proceed in a "living" fashion, providing low-polydispersity PBOS and block copolymers of the type PBOS-b-PS, where TEMPO is 2,2,6,6-tetramethylpiperidin-1-oxyl and PS is polystyrene. The acidolysis of the polymers gave well-defined poly(p-vinylphenol) (PVP) polymers. The PVP-b-PS block copolymers were observed to exhibit lamellar and cylindrical microdomain morphologies depending on the copolymer composition. The rate of BOS polymerization is independent of the "initiator" (BS-TEMPO) concentration, being essentially equal to the rate of thermal polymerization. The polydispersity of PBOS depends on polymerization time but not on the degree of polymerization, under the studied experimental conditions. References: 37