Confined Growth of Poly(butylene succinate) in Its Miscible Blends with Poly(vinylidene fluoride): Morphology and Growth Kinetics

详细信息    查看全文

• 作者：Tianchang Wang ; Huihui Li ; Feng Wang ; Shouke Yan ; Jerold M. Schultz
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：June 23, 2011
• 年：2011
• 卷：115
• 期：24
• 页码：7814-7822
• 全文大小：1216K
• 年卷期：v.115,no.24(June 23, 2011)
• ISSN：1520-5207

文摘

The morphology and confined crystallization behavior of poly(butylene succinate) (PBS) in miscible poly(vinylidene fluoride) (PVDF)/PBS blends has been studied using differential scanning calorimetry (DSC) and optical and atomic force microscopy (OM and AFM). It was found that PBS crystal lamellae nucleated and grew confined inside the matrix of PVDF spherulites. Crystallized PBS domains grow with an ellipsoidal outline within PVDF spherulites formed at a relatively high PVDF crystallization temperature (T_c,PVDF), while circular domains, engulfing several PVDF spherulites, are seen when growing in the PVDF spherulites created at lower T_c,PVDF. The growth kinetics of PBS confined in the PVDF matrix was investigated under various conditions. The growth rate of PBS (G_PBS) increases with decreasing crystallization temperature and increasing PBS content under a given PVDF crystallization temperature (T_c,VDF). For T_c,PVDF above 145 掳C, G_PBS decreases with T_c,PVDF for both 50:50 and 30:70 PVDF/PBS blends. However, for T_c,PVDF below 145 掳C, 50:50 and 30:70 PVDF/PBS blends exhibit the opposite G_PBS trend; that is, G_PBS for the 50:50 blend decreases with decreasing T_c,PVDF, while for the 30:70 PVDF/PBS blend G_PBS increases with decreasing T_c,PVDF. It is shown that this behavior cannot be associated with the effect of crossing the boundary of smaller PVDF spherulites formed at a lower temperature. Rather, the behavior appears to be related to the interleaving growth of PBS lamellae among PVDF lamellae or between bundles of PVDF lamellae (fibrils), as in situ AFM observation shows. It is found that the interconnectedness of the molten pockets within the PVDF spherulites, which depends on the PVDF crystallization temperature, is an important factor determining the growth kinetics of PBS confined within the PVDF scaffold.