Stereospecific polymerization considered as copolymerization

Abstract

Abstract Polymerization of an unsymmetrically substituted olefin can be considered as an example of copolymerization of two stereoisomers with four typical propagation rates k ** and probabilities P ** . Stereospecific catalysts which operate only by increasing the probability of P dd over P dl and P ll over P ld produce isotactic polymers of the same sequence length distribution as typical copolymers with like propagation probabilities. Stereospecific catalysts with stereoisomeric sites at which P dd ≠ P dl should be capable of producing isotactic polymers in which sequences of a single configuration on each polymer chain are greatly preferred.