Studies on Miscibility, Crystallization Behavior and Morphology in Binary Crystalline Polymer Blends PBT/PAr(I27-T73)

• Main Authors: Shih-Huang Tung, 童世煌纷
• Other Authors: Wen-Bin Liau
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/00859738259564030460

碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 88 === The miscibility, crystallization behavior and morphology of binary crystalline blends of poly(butylenes terephthalate) [PBT] and polyarylate based on Bisphenol A and a 27/73 mole ratio of isophthalic and terephthalic acids [PAr(I27-T73)] have been investigated by differential scanning calorimetry (DSC) and polarizing optical microscope (POM). The results of DSC revealed that the blend system exhibited a single composition-dependent glass-transition temperature over the entire composition range. The equilibrium melting point depression of PBT was observed, and Flory interaction parameter c12=-0.96 was obtained. This indicated that the blends were thermodynamically miscible in the melt. The crystallization rate of PBT decreased as amounts of PAr increased and a contrary trend was found when PAr crystallized with increasing amounts of PBT. The addition of high-Tg PAr would suppress the segmental mobility of PBT while low-Tg PBT would have promotional effect toward PAr. From the observation of POM, it could be supposed that owing to effect of crystallization rate, amorphous PAr was trapped in PBT spherulites when PBT crystallized and amorphous PBT was excluded out of the PAr spherulites when PAr crystallized. The crystallization rate and melting point of PBT was significant decreased when PAr crystal was previously formed. It is due to the constraint of the PAr crystal phase.