摘要
研究了取代茚基二价稀土配合物(1-C5H9C9H6)2Yb(THF)2催化甲基丙烯酸-N,N-二甲胺乙酯的聚合。结果表明,配合物(1-C5H9C9H6)2Yb(THF)2作为单组分催化剂对甲基丙烯酸-N,N-二甲胺乙酯的聚合显示出较高的催化活性,反应温度、时间、催化剂用量及溶剂性质对聚合反应转化率和产物分子量有较大影响,在以甲苯为溶剂的催化体系中加入少量的极性溶剂THF,聚合活性有明显提高。其他几种取代茚基稀土配合物也显示出高的催化活性,其活性有下列次序:(1-C5H9C9H6)2Sm(THF)≈(1-C2H5C9H6)2Sm(THF)2>(1-C5H9C9H6)2Yb(THF)2>(1-PhCH2C9H6)2Sm(THF)2,二价钐配合物较二价镱的相应配合物具有较高的催化活性。聚合产物的分子量及分子量分布通过凝胶渗透色谱法表征,立构规整性由1H NMR谱表征,所得聚合物以间同立构为主。
The polymerization of dimethylaminoethyl methacrylate （DMAEMA） catalyzed by 1-cyclopentylindenyl lanthanide （Ⅱ） complex （1-C5H9C9H6 ）2Yb （THF）2 was investigated. The results indicated that the complex （1-C5H9C9H6）2Yb （THF）2 as single component catalyst showed high activity, the conversion of the polymerization and the molecular weight of the polymer were affected by temperature, time, amount of catalyst and solvent in polymerization process. The catalytic activity of （1-C5H9C9H6）2Yb （THF）2 would be enhanced significantly when a little of polar solvent THF was added into polymerization system in which toluene was selected as solvent. The optimal temperature of polymerization was about 0 ℃. Other modified substituted indenyl lanthanide （Ⅱ） complexes also showed good catalytic activity. The order of catalytic activity of the complexes was as follows： （1-C5H9C9H6）2Sm（THF） （ 1- C2HsC9H6）2Sm （THF）2 〉 （ 1-CsHgCgH6 ）2Yb （THF）2 〉 （ 1-PhCH2C9H6）2Sm （ THF ）2. The steric regularity of poly （dimethylaminoethyl methacrylate） （PDMAEMA） was characterized by 1^ H NMR spectra. The polymerization gave syndiotacticity-rich PDMAEMA. The molecular weight and molecular weight distribution of PDMAEMA were measured by GPC.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2007年第6期688-691,共4页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金资助项目(20072027)
茂名学院博士基金项目
