Polymerization of 1,2‐epoxypropane and copolymerization with carbon dioxide catalyzed by metalloporphyrins
Polymerization of 1,2‐epoxypropane and copolymerization with carbon dioxide catalyzed by metalloporphyrins
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DOI：
10.1002/macp.1978.021790529
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发表时间：
1978-05
影响因子：
2.5
通讯作者：
N. Takeda;S. Inoue
中科院分区：
文献类型：
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作者：
N. Takeda;S. Inoue
均聚反应在氩气氛下、20℃、无溶剂下进行。共聚在相同条件下在1巴(CO2鼓泡)或8.1巴CO2压力下进行。除去挥发性物质后，将部分反应混合物溶解在四氢呋喃中，然后通过聚四氟乙烯过滤器滤除金属卟啉。将滤液进行凝胶渗透色谱法测定聚合物的平均分子量和分子量分布，以聚丙二醇为标准。使用氯仿/己烷作为洗脱液，使产物的苯溶液通过填充有硅胶的柱3次，进行聚合物的分离。共聚物3中氧羰基单元的含量通过'H NMR3)测定，聚(1，2-环氧丙烷)的立构规整度通过13C NMR4'测定。在所检测的金属卟啉中(表I)，四苯基卟啉(4)/二乙基氯化铝(1:1)催化剂体系6表现出特别高的活性。通过该体系，38％的2在20℃下20分钟内聚合，而二乙基氯化铝需要1440分钟才能聚合7、3％的2。在20℃的CO 2 大气压下，催化剂体系1b或5得到共聚物3，尽管氧羰基单元的含量较低(表2)。当共聚在较高CO 2 压力(8，1巴)下进行时，氧羰基单元的含量增加(从15摩尔％至40摩尔％)。对于系统6，即使在CO 2 存在下也仅进行2的均聚(1，0巴和8，1巴)。当N-甲基四苯基卟吩(7)/二乙基-
Homopolymerization was carried out in an argon atmosphere at 20 C without solvent. Copolymerization was carried out under 1 bar (bubbling of COz) or 8, l bar pressure of COz under the same conditions. After the removal of volatile materials, a part of the reaction mixture was dissolved in tetrahydrofuran and then filtered off from metalloporphyrin by a Teflon filter. The filtrate was subjected to gel permeation chromatography for the determination of the average molecular weight and the distribution of molecular weight of polymer, using poly (propy1ene glycol) as standard. Isolation of the polymer was carried out by passing the benzene solution of the products through the column packed with silica gel three times using chloroform/hexane as eluent. The content of the oxycarbonyl units in the copolymer 3 was determined by'H NMR3), the tacticity of poly (l, 2-epoxypropane) by I3C NMR4'. Among the metalloporphyrins examined (Tab. I), the tetraphenylporphine (4)/diethylalu-minium chloride (1: l) catalyst system 6 exhibits a particularly high activity. By this system, 38% of 2 polymerized in 20min at 20 C, whereas diethylaluminium chloride required 1440min to polymerize 7, 3% of 2.Under atmospheric pressure of C02 at 20 C, the catalyst systems lb or 5 gave copolymer 3, though the content of oxycarbonyl units was low (Tab. 2). When the copolymerization was carried out under a higher C02 pressure (8, l bar), the content of oxycarbonyl units increased (from 15 to 40 mole-%). With the system 6 only homopolymerization of 2 proceeded even in the presence of C02 (1, O bar and 8, l bar). When N-methyltetraphenylporphine (7)/diethyl-