MODELING CARBOCATIONIC POLYMERIZATIONS - KINETICS OF THE REACTIONS OFCARBOCATIONS WITH ALKENES

Reactions of carbocations with olefins and related x-nucleophiles foll ow second order kinetics, first order with respect to carbocation and first order with respect to olefin. The rate constants are equal for p aired and non-paired ions and independent of the nature of the negativ e counter-ions. Rate constants k < 10(7)-10(8) L mol(-1) s(-1) can be calculated by lg k(20 degrees C) = s (N+E), where E represents the str engths of the electrophiles, while nucleophiles are characterized by t he slope parameter s and the nucleophilicity parameter N. These parame ters can be used for selecting initiators for carbocationic polymeriza tions and for designing copolymers.