Coupling Reaction of Polystyryl Anion with Chloromethylated Polystyrene in the Presence of Styrene

Abstract

Chloromethylated polystyrerte reacts with polystyryl anion in the presence of styrene at -78 C in THF. The decrease in the concentration of living end was measured photometrically by using an apparatus equipped with an optical cell capable of working at low temperatures. The coupling reaction was completed within about 20 min. The number of branches per backbone polymer molecule of graft copolymer obtained in the presence of styrene is greater than that in the. absence of styrene, . Coupling proceeds again in the presence of styrene. In the absence, . of styrene, steric factors are important for determining e the exten4t of coupling in some cases, especially when the molecular weight of polystyryI anion is large. However, these factors have no great influence on the formation of the graft copolymer (i. e., the extent of coupling) in the presence of styrene.