Crystallization kinetics of poly(ethylene oxide) diluted with xylene

Abstract

The crystallization kinetics of poly(ethylene oxide)-xylene mixtures with volume fractions of solvent v 1 = 0.52, 0.93 and 0.99 has been investigated by means of dilatometry. At low extents of crystallinity, isotherms are well expressed by the free growth approximation with exponent n = 3 for the concentrated systems ( v 1 = 0.52 and 0.93) and n = 4 for the more dilute solution ( v 1 = 0.99). The overall rate temperature coefficient was analysed using the theory pertinent to polymer-diluent mixtures. Assuming that the product σ′ e σ u , where σ′ e is the apparent basal free energy and σ u is the lateral free energy of the critical nucleus, is independent of concentration, the dissolution temperature for different dilutions as well as the interaction parameter χ 1 have been estimated.