丙酮诱导聚碳酸酯的结晶行为

在298 K, 采用液相丙酮或26.5 kPa蒸气压的气相丙酮, 对双酚A聚碳酸酯(BAPC)的液相或气相诱导结晶行为进行研究. 实验结果表明, 在诱导结晶的起始阶段, 非晶态BAPC结晶能力得到极大的提高. 气相诱导BAPC结晶的结晶速度和结晶度均低于液相诱导结晶的结果. 广角X射线衍射(WAXD)测试结果表明, 与BAPC热结晶样品相比, 丙酮液相或气相诱导BAPC结晶生成的晶体具有完善度低、晶粒尺寸小、熔点低, 而结晶度高的结构特点. 采用扫描电子显微镜(SEM)分别对液相或气相丙酮诱导BAPC结晶样品表面形态进行了观察, 研究了不同诱导机制下BAPC的结晶生成球晶的形态与机制.

Acetone-induced Crystallization Behavior of Polycarbonate

Acetone liquid-induced and vapor-induced (26.5 kPa) crystallization behavior of bisphenol-A polycarbonate (BAPC) at 298 K was studied and compared. The results showed that in the initial stage of the induced crystallization, the ability of the amorphous BAPC to crystallize had been greatly enhanced with a rapid increase of crystallinity. Compared with liquid-induced crystallization, the crystallization rate and crystallinity of vapor induced crystallization were much lower. Wide-angle X-ray diffraction spectra displayed that liquid induced or vapor induced crystallization of BAPC samples enjoyed such characters as smaller and less perfect crystal grains and a higher crystallinity in comparison with a melting crystallization process. The morphology of BAPC samples after liquid induced or vapor induced crystallization was examined by means of a scanning electron microscope and the different spherulite morphologies as well as formation of spherulites of crystallized samples prepared by the two inducing methods were studied.