HE－1型催化剂异相聚合乙烯结晶性能研究　Ⅱ．超高分子量PE结晶行为

STUDIES ON CRYSTALLIZATION BEHAVIOR OF POLYETHYLENE POLYMERIZED WITH HE-1 TYPE CATALYST Ⅱ. CRYSTALLIZATION OF ULTRAHICH MOLECULAR WEIGHT POLYETHYLENE

用小角Ｘ－射线散射，广角Ｘ－射线衍射，差示扫描量热法，研究了ＨＥ－１型钛系催化剂异相聚合超高分子量聚乙烯的稀溶液的结晶和熔融结晶的熔点，熔化热，结晶度，长周期，晶区厚度和非昌区厚度随分子量与结晶温度的关系．并着重讨论了熔融结晶和初生态结晶的不同过程机理．结果表明：ＵＨＭＷＰＥ稀溶液结晶的结晶度（Ｘｃ％），长周期（Ｌ）和晶区厚度（Ｌｃ）与分子量Ｍｗ无关，随结晶温度升高而增加，非晶区厚度（Ｌａ）与分子量和结晶温度均无关，熔点Ｔｍ随分子量增大稍有升高．熔融结晶样品长周期与分子量无关，却和结晶温度和时间有关．其结晶度和晶区厚度随分子量增大而下降，非昌区厚度和熔点均随分子量增大而增大，初生态粉末中没发现长周期，却发现有较高熔点．

rystallization behavior of ultrahigh molecular weight polyethylene polymerized with HE--1 type catalyst has been studied by means of small angle X--rayscattering (SAXS), wide angle X--ray diffraction(WAXD) and differential scanningcalorimetry(DSC). It was found that crystallinity, long periods, crystallite regionthickness and amorphous region thickness formed in dilute solution are independentof molecular weight and are related with crystallization temperature. If crystalswere obstained from melt crystallization. .its long periods are independent of molecular weight, but related with crystallization temperature and time. Clystallinityand crystallite region thickness decrease with molecular weight increase. Amorphousregions increase with molecular weight and the melting temperature increases withmolecular weight. The nascent crystals have higher melting points than those frommelt, but the long period of nascent crystals has not been found.