【摘要】 <正> 在高聚物结晶动力学的研究中,分子量对结晶速率的影响是一个有实际意义和理论兴趣的研究课题,由于聚烯烃可以得到分子量变化范围相当宽(MW从10~3到10~6)的试样,因而它是研究结晶速率分子量依赖性较合适的对象,其中研究最多的是聚乙烯和聚丙烯。从前入的研究报道看来,影响聚丙烯结晶速率的因素比聚乙烯要复杂。除了聚丙烯可生成多种晶型结构,会影响其结晶速率以外,用不同聚合方法制备的试样,由于其链结更多还原

【Abstract】 The effect of molecular weight (MW) on the isothermal crystallization of polypropylene (PP) has been studied using a differential scanning calorimeter (DSC). PP samples with Mw ranging from 7×104 to 30×104 were prepared with controlled oxidative degradation. Based on the experimental data of crystallization peak time, it is obvious that the isothermal crystallization rate of PP decreases with decreasing MW. This result is consistent with the phenomena of smec-tic structure formation in fiber spinning process and injection moulding.更多还原