水溶性單體在水相中以鈷金屬錯合物催化之活性自由基聚合

Living Radical Polymerization (LRP) of Water-Soluble Monomers Mediated by Cobalt Catalyst in Aqueous Phase

杜宗翰(Tsung-Han Tu)

指導教授 ： 彭之皓

國立清華大學/理學院/化學系/碩士(2013年)

摘要

我們成功合成出具水溶性的Co(salen*)並用於調控丙烯酸的活性自由基聚合反應，在聚合反應中觀察到分子量隨單體轉化率上升而線性增加且分子量分布相對集中 (PDI = 1.3 ~ 1.5)，並且在聚合反應中加入不同量的起始劑，發現起始劑量越多聚合物分子量越趨近理論值，藉由計算推測知在聚合反應時的機制以可逆終止反應 (reversible termination) 機制為主且其平衡常數應為Kd = 2.4 x10-9。最後使用了(salophene) CoIII-PAA (Mn = 42100 g mol-1, PDI = 1.46) 做為高分子起始劑成功合成出PAA-b-PMA嵌段共聚物(Mn = 70900 g mol-1, PDI = 1.71)。
Di(pyridin-2-yl)methyl acrylate (DPyMA) 被成功的合成出來，並成功地經由傳統自由基聚合反應合成出poly(DPyMA)，此聚合物因側邊含有吡啶而具有與金屬配位的能力，將poly(DPyMA)與CuBr2反應後發現溶解度大幅下降，藉由DPyMA與CuII配位的晶體結構推測在聚合物中可能有交聯的現象導致溶解度下降。

關鍵字

活性自由基聚合 ； 鈷調控自由基聚合 ； 丙烯酸甲酯 ； 丙烯酸 ； 功能性高分子

並列摘要

Acrylic acid polymerization has been mediated by water soluble (salen*)CoII complexes. The living characters of linear increased molecular weight with conversion, relatively low polydispersity values, and the synthesis of block copolymer were approached. The kinetic study with different amount of azo-initiator indicated that the control process is mainly based on reversible termination pathway and the equilibrium constant was estimated as 2.4 x10-9.
Functional monomer, “Di(pyridin-2-yl)methyl acrylate” (DPyMA), which can coordinate with metal ions, was synthesized successfully. Poly(DPyMA) and DPyMA coordinated copper complex were also obtained. However, the reaction of the CuBr2 and poly(DPyMA) led to the precipitation which was proposed as the crosslinked product of poly(DPyMA) and Cu ions. Living radical polymerization of DPyMA is still being processed.

並列關鍵字

Living radical polymerization ； Cobalt-mediated radical polymerization ； Cobalt salen ； Acrylic acid ； Di(pyridin-2-yl)methyl acrylate ； Functional polymers

參考文獻

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