Preparation of a block copolymer by hydrolysis and subsequent oxidative coupling of the chain ends of poly(methyl methacrylate) and polystyrene, containing amidinothio end groups

Abstract

Polymers with an amidinothio end group (-S-eNH are easily obtained1v2) by polymerization of a vinyl monomer with redox initiators involving thiourea (TU) as the reductant. Such end groups are reported to hydrolyse readily under alkaline conditions forming mercapto end groups. In the presence of air, intermolecular oxidative coupling of these chain ends takes place leading to an appreciable increase in intrinsic viscosity or molecular weight I). This sequence of reactions was employed in the pesent work with the objective of preparing block copolymers from a mixture of poly(methy1 methacrylate) and polystyrene, prepared separately from the respective monomers by Fei3-TU as redox initiator. NH, Nn CH3 NH II

Kinetic and ESR studies on radical polymerization of methyl methacrylate in the presence of fullerene

“…These fractions are considered to be homopoly(St), homopoly(MMA), and the copolymer of St and MMA, respectively. [27][28][29] The results observed are summarized in Table II. Thus the polymer yield was almost independent of the presence or the absence of C 60 -containing poly(MMA) although the molecular weight of polymer formed in the presence of the poly(MMA) was somewhat lower than that of polymer in the absence of the poly(MMA).…”