Solution history effect in isotactic polybutene-1

Abstract The crystallization of isotactic polybutene-1 (PB-1) from dilute solutions was studied by Holland and Miller, who observed that the resulting crystal structure was dependent on the temperature of dissolution as well as the temperature of crystallization. Their study has been reexamined and further explored in detail under more general experimental conditions. The effect of using different crystal polymorphs as the starting material and that of keeping the solution for various lengths of time at selected temperatures before crystallization have been studied. The results generally agree with the previous findings of Holland and Miller and provide further information which suggests that PB-1 molecules assume definite helical conformations in solution. With time, the chains tend to transform from their original solid-state conformations to the one which is thermodynamically favored at the solution temperature.