Effect of styrene–butadiene–styrene triblock copolymer on non-isothermal crystallization kinetics and melting behavior of syndiotactic 1, 2-polybutadiene

Abstract

Syndiotactic 1,2-polybutadiene (s-PB), as a semi-crystalline polymer, has many excellent properties, such as thermal stability and processability. Meanwhile, styrene–butadiene–styrene triblock copolymer (SBS) is an amorphous thermoplastic elastomer. Therefore, modifying s-PB with SBS will affect the crystallization and melting behavior of s-PB/SBS blends. In this work, differential scanning calorimetry technique was used to investigate the effect of the introduction of SBS on non-isothermal crystallization and melting behavior of s-PB. Non-isothermal crystallization kinetics was analyzed by Jeziorny, Ozawa and Mo’s methods. Jeziorny method indicates that the crystallization process can be divided into two stages as primary crystallization and secondary crystallization. Mo’s method gives a better description of the non-isothermal crystallization kinetics of s-PB/SBS blends (the mass ratios are 100/0, 95/5, 90/10, and 80/20). These two methods both indicate that the crystal process becomes difficult with increasing SBS content, but the introduction plays little or no effect on the nucleation mechanism and crystal growth type of s-PB in the bends. Comparatively, Ozawa method is not suitable for this system. The effective energy barriers during the non-isothermal crystallization process are also analyzed via Friedman method.