摘要
The polymerization of dimethylaminoethyl methacrylate （DMAEMA） catalyzed by the 1-cyclopentylindenyl lanthanide （Ⅱ） complex （1-C5H9C9H6）2Yb （THF）2 was investigated. The results indicated that the complex （1- C5H9C9H6）2Yb （THF）2 as a 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 the polymerization process. The catalytic activity of （1-C5H9C9H6）2Yb （THF）2 enhanced significantly when a small amount of polar solvent THF was added into the polymerization system in which toluene was selected as the 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- C2 H5 C9H6 ）2 Sm（THF）2 〉 （1 -C5 H9 C9 H6 ）2 Yb（THF）2 〉 （1 -PhCH2 C9 H6 ）2 Sm（THF）2. The steric regularity of p oly （dimeth- ylaminoethyl methacrylate） （PDM AEM A） was characterized by 1H NM R spectra. The polymerization provided syndio- tacticity-rich PDM AEM A. The molecular weight and the molecular weight distribution of PDM AEM A were measured by gel permeation chromatography.
The polymerization of dimethylaminoethyl methacrylate （DMAEMA） catalyzed by the 1-cyclopentylindenyl lanthanide （Ⅱ） complex （1-C5H9C9H6）2Yb （THF）2 was investigated. The results indicated that the complex （1- C5H9C9H6）2Yb （THF）2 as a 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 the polymerization process. The catalytic activity of （1-C5H9C9H6）2Yb （THF）2 enhanced significantly when a small amount of polar solvent THF was added into the polymerization system in which toluene was selected as the 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- C2 H5 C9H6 ）2 Sm（THF）2 〉 （1 -C5 H9 C9 H6 ）2 Yb（THF）2 〉 （1 -PhCH2 C9 H6 ）2 Sm（THF）2. The steric regularity of p oly （dimeth- ylaminoethyl methacrylate） （PDM AEM A） was characterized by 1H NM R spectra. The polymerization provided syndio- tacticity-rich PDM AEM A. The molecular weight and the molecular weight distribution of PDM AEM A were measured by gel permeation chromatography.
基金
Project supported by the National Natural Science Foundation of China (20072027)
