Effects of polytrimethylene terephthalate on crystallization and melting behavior of beta-polypropylene in the blends

It has been observed that the formation of beta-crystal is suppressed when beta-polypropylene (beta-PP) is blended with crystalline polymers, but the reason is still uncertain. In this study, we investigated the influence of the crystallization conditions of polytrimethylene terephthalate (PTT), such as melt crystallization, cold crystallization, isothermal crystallization temperature, and crystallization time on the beta-nucleation behavior of PP phase in the beta-PP/PTT blends. The results showed that the beta-crystal content of PP phase in the blends decreases with increasing of PTF content. Cold crystallization of PTT would mainly induce the formation of alpha-crystal in PP component, whereas melt crystallization would induce the formation of beta-crystal PP in their blends. The degree of crystallinity of PTT increases by improving the crystallization temperature or extending the time of crystallization, which leads to the production of more at-crystal in PP component. This means that the second component could inhibit the formation of beta-crystal in PP. (C) 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.