Kinetic Studies of the Alternating Copolymerization of Cyclic Acid Anhydrides and Epoxides, and the Terpolymerization of Cyclic Acid Anhydrides, Epoxides, and CO2 Catalyzed by (salen)CrIIICl
Kinetic Studies of the Alternating Copolymerization of Cyclic Acid Anhydrides and Epoxides, and the Terpolymerization of Cyclic Acid Anhydrides, Epoxides, and CO2 Catalyzed by (salen)CrIIICl
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DOI：
10.1021/ma2026385
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发表时间：
2012-03-13
期刊：
影响因子：
5.5
通讯作者：
Escobedo, Christina
中科院分区：
文献类型：
--
作者：
Darensbourg, Donald J.;Poland, Ross R.;Escobedo, Christina
使用(salen)CrCl/鎓盐催化剂，一系列环状酸酐与几种环氧化物进行共聚，得到了具有高分子量和窄分子量分布的聚酯。 (salen)CrCl 催化剂在式 PPNX (X = Cl-, N-3(-)) 的鎓盐存在下用于酸酐、马来酸 (MA)、琥珀酸 (SA)、邻苯二甲酸 (PA)、环己烯 (CHE) 和环己烷 (CHA) 与环氧化物、环己烯氧化物 (CHO)、环氧丙烷的共聚 (PO) 和氧化苯乙烯 (SO) 导致单体完全交替链化，从而提供纯聚酯。对邻苯二甲酸酐和环氧环己烷单体在甲苯溶液中开环共聚的温度依赖性研究得出了 Delta H-double dagger = 67.5 kJ mol(-1) 和 Delta S-double dagger = -95.3 J mol(-1) 的活化参数，其中限速步骤是链酸酐对环氧化物的开环。对于环状酸酐(CHA)，与环氧化物的反应活性的相对顺序为PO > CHO >= SO，对于环氧化物(CHO)，共聚的相对速率为CHA > PA > CHE。 (salen)CrCl/PPNN3 催化剂体系还被证明可以有效地将 CHO/邻苯二甲酸酐/CO2 三元聚合，得到二嵌段共聚物，从而一锅合成聚(酯-共-碳酸酯)。合成聚酯的 T-g 值显示温度范围超过 130 摄氏度，从 +95 摄氏度到 -39 摄氏度。
Copolymerization of a series of cyclic acid anhydrides with several epoxides using (salen)CrCl/onium salt catalysts has afforded polyesters with high molecular weights and narrow molecular weight distributions. The (salen)CrCl catalyst in the presence of the onium salts with formula PPNX (X = Cl-, N-3(-)) for the copolymerization of the anhydrides, maleic (MA), succinic (SA), phthalic (PA), cyclohexene (CHE), and cyclohexane (CHA) with the epoxides, cyclohexene oxide (CHO), propylene oxide (PO), and styrene oxide (SO) resulted in completely alternating enchainment of monomers to provide pure polyesters. Temperature dependent studies of the ring-opening copolymerization of phthalic anhydride and cyclohexene oxide monomers in toluene solution have yielded activation parameters of Delta H-double dagger = 67.5 kJ mol(-1) and Delta S-double dagger = -95.3 J mol(-1), where the rate limiting step was ring-opening of the epoxide by the enchained anhydride. For the cyclic acid anhydride (CHA), the relative order of reactivity with epoxides decreased PO > CHO >= SO, and for the epoxide (CHO) the relative rate of copolymerization was CHA > PA > CHE. The (salen)CrCl/PPNN3 catalyst system was also shown to effectively terpolymerize CHO/phthalic anhydride/CO2 to afford diblock copolymers, thereby producing in a one pot synthesis poly(ester-co-carbonate). T-g values of the synthesized polyesters displayed a temperature range over 130 degrees C, from +95 degrees C to -39 degrees C.