等规聚丙烯无定形相和中间相向α晶的等温转变机理研究

Mechanism of Isothermal Transformation from Amorphous Phase and Mesophase to Alpha Crystal of Isotatic PP

用宽角X射线衍射和傅立叶变换红外光谱仪研究了等规聚丙烯的低温等温结晶。结果表明,在快速淬冷过程中中间相与α晶的生成动力学之间存在竞争,而在恒温结晶的过程中晶型的转化则是由热力学稳定性来决定的。淬冷到40℃至55℃的聚丙烯可以同时形成中间相和α晶,在恒温过程中α晶有增加,但是转化来源会因温度不同而不同。

The isothermal crystallization of isotactic polypropylene （iPP） was studied by means of WAXD and at different temperatures. In the quenching process, the occurrence of mesophase and α crystal competed with each other, while during the isothermal crystallization transformation of phase, it was decided by the thermodynamic stability of each phase. For isotactic PP quenched to different temperatures from 40 to 55 ℃, both mesophase and α crystal occurred. In the isothermal process at all temperatures, the content of α crystal increased with time, while the origins of transformation were different at different temperatures.