Formation and Stabilization of Crystal Nuclei in Isotactic Polybutene-1 Aged below Glass Transition Temperature

Publication date: Available online 14 February 2020Source: PolymerAuthor(s): Peiru Liu, Yanhu Xue, Yongfeng MenAbstractAging of glassy isotactic polybutene-1 (iPB-1) below the glass transition temperature (Tg) leads to remarkable acceleration of the subsequent isothermal crystallization due to the promotion of crystal nuclei. The formation and development of crystal nuclei during aging below Tg and during heating to the crystallization temperature have been probed by fast scanning chip calorimetry. The size and stability of the crystal nuclei change with the aging time. A short aging below Tg can only induce nuclei with small sizes which can grow into bigger stable one during the heating process above Tg if the heating rate is not high enough. With a prolonged aging time below Tg, bigger stable nuclei can also be developed, and its number increases till reaches a maximum value. These results suggest that noncooperative local motions rather than cooperative segmental motions in glassy iPB-1 are responsible to the formation of crystal nuclei during aging below Tg.

Source: Polymer - February 15, 2020 Category: Chemistry Source Type: research