铁系化合物催化脂肪族环酯聚合反应

Polymerization of Aliphatic Cyclic Ester using Iron Compounds as Catalysts

以常见铁系化合物为催化剂对L-丙交酯(L-LA)及与ε-己内酯(ε-CL)的开环聚合反应进行了研究,探讨了体系反应温度、反应时间和催化剂用量等因素对聚合反应的影响,以及L-丙交酯在以铁系化合物作为催化剂时的开环聚合反应机理。用凝胶渗透色谱(GPC)、核磁共振氢谱(1H-NMR)、电感耦合-等离子发射光谱(ICP-AES)等方法对产物进行了表征,并对聚合物的热性能进行了检测。结果表明:在所用4种常见铁化合物中,乙酰丙酮亚铁Fe(acac)2和乙酰丙酮铁Fe(acac)3是较高效的催化剂,其对L-LA的催化反应可使单体转化率达90%以上,数均分子量达1.2×105,分子量分布约1.4。Fe(acac)3同时也是L-LA与ε-CL共聚反应的有效催化剂。

Ring-opening polymerization of L-Lactide（L-LA） and copolymerization of L-LA and ε-caprolactone（ε-CL） using iron complexes as catalysts were investigated.The effects of temperature,time and catalyst amount etc.were studied.The polymeric products were characterized by GPC,1H-NMR,ICP-AES and DSC.The polymerization mechanism was explored.Results show that iron（Ⅲ） acetylacetonate（Fe（acac）3） and iron（Ⅱ） acetylacetonate（Fe（acac）2） are the more efficient catalysts,since the monomer conversion was up to 90%;the number average molecular weight of the product is 1.2×105 and the molecular weight distribution（Mw/Mn） is 1.4.Fe（acac）3 is also an effective catalyst for copolymerization of L-LA and ε-CL.