The three processes of phase II–I transformation of isotactic polybutene-1

Abstract

The spontaneous transformation of the unstable tetragonal phase II to the stable twined hexagonal phase I of isotactic polybutene–1 at room temperature and atmospheric pressure was shown to proceed by one of three different mechanisms with these mechanism being neutral (N), increasing (P) or decreasing (M) the phase transformation rate. The rate was shown to be influenced by environmental effects. The environment can increase or decrease the phase transformation rate and, to a smaller extent, influence the sample crystallinity and the amount of the residual, untransformed phase II. The transformation rate was principially affected by the segmental mobility, increased by solvents or decreased by some chemical compounds or groups (e.g.–CH2-CH2–as a comonomer). The transformation rate of the M process starts after an induction period during which the transformation nuclei are blocked. © 2018 Taylor & Francis Group, LLC.