Kinetically controlled phase transitions in LC polymers. I. Isokinetic range crossover for the Sm B-Sm H transition in a side-chain polysiloxane

The kinetics of smectic-phase formation in a siloxane copolymer, as compare d with the crystallization of the relating homopolymer, was studied by the AVrami analysis of DSC data. A crossover from the diffusion-controlled kine tics (the Avrami exponent kappa similar to0.35) to the two-dimensional free -growth mode (kappa similar to1.5) with increasing temperature was detected . The influence of the annealing temperature on the sequence of mesophases, transition temperatures, and enthalpies of the polymers was also investiga ted. (C) 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 1055-10 60, 2001.