茂基二价钐配合物高效催化己内酯开环聚合

以茂基二价钐配合物(C5H5)2Sm(THF)作为单组分催化剂催化己内脂开环聚合反应,考察了催化剂用量、聚合反应时间和聚合反应温度对己内酯聚合反应的影响.结果表明,配合物(C5H5)2Sm(THF)对己内酯聚合有极高的催化活性且产物的数均分子量较高,当催化剂与单体摩尔比为1:5000时,聚合产率仍可达到50.3%,数均分子量可高达32.4×104;温度升高,聚合反应的转化率增加,聚合产物数均分子量降低;催化剂用量增加,聚合转化率增加,聚合产物分子量降低,聚合产物的分子量分布较窄;通过凝胶色谱法对聚合产物的分子量及分子量分布进行了表征.

High Effective Ring-open Polymerization of ε-Caprolactone Catalyzed by Bicycolopentadienyl Samarium(Ⅱ) Complex (C5H5)2Sm(THF)

Lanthanide (II) complex (C5H5)2Sm(THF) applied in catalyzing the polymerization of ε-caprolactone was investigated. The results indicated that the complex as single component catalyst showed very high activity and the number-average molecular weight of the polymer gained was also very high. For example, when the molar ratio of catalyst to monomer was 1/5000, the conversion could still reach 50.3% and the number-average molecular weight of the polymer gained was as high as 32.4?104. The conversion of the polymerization and the number-average molecular weight of the polymers were affected by temperature, time of polymerization and use level of catalyst in polymerization process. The number-average molecular weight of the polymer decreased, the molecular weight distribution was slightly wide, but the conversion increased as the polymerization temperature increasing. The conversion increased and the number-average molecular weight decreased as the dosage of catalyst increased. The molecular weight distribution of polycaprolactones gained were narrow. The number-average molecular weight and molecular weight distribution of polycaprolactone were measured by GPC.