丙烯催化聚合产物的X射线衍射分析——Ⅰ.反应过程中形成的结构

用X射线衍射考察了反应条件下形成的聚丙烯的超分子结构,表明均形成α型结晶。从测得的晶胞参数计算晶区密度d_c=0.9127—0.9688g/cm~3,即d_c在一定范围内的变化,证明聚合条件对聚合物结构——分子链在晶区的堆砌密度有重大影响。此外,用DSC考察产物的热性能,表明熔点等同样受分子链堆砌紧密程度的影响。

X-Ray Diffraction of Catalytic Polymerization Product of Propene——Ⅰ. Structure Formed in Reaction Step

The structure of polypropylene crystal formed during catalytic polymerization was investigated using X-ray diffraction, The results indicate that all crystals are ot α-form, and the unit cell parameter varies with conditions of polymerization. Values of crystalline density are calculated from the unit cell parameter, and are found to fall within the range of 0.9172—0.9588g·cm(-3). Thus, crystal structure of copolymer is significantly affected by conditions of copolymerization. Moreover, the results of investigating the thermal properties of the products have shown that melting point and other properties are also affected by how compact the molecular chains are packed together.