Nd-AI双金属活性体的活性部位及其对共轭双烯烃聚合机理的研究

ACTIVE SPECIES COMPOSITION AND DIENE POLYMERIZATION MECHANISM OF Nd-Al BIMETALLIC COMPLEX

稀土催化剂活性体对双烯烃配位聚合的研究已有很多报道,使用催化剂活性体对双烯烃聚合机理的研究比以前所用的多组分混合物的催化体系显然具有很大的优越性。本文利用NdCl_3·3TBP和Ndel_3·3P_(350)配合物与Al(i-Bu)_3体系所得活性体合成了共轭双烯烃低聚物,用IR、^(13)C-NMR光谱研究了这些低聚物分子的链端结构,从而推测活性体的活性部位组成和聚合机理。

Low molecular weight polydienes were obtained with Nd-Al bimetallic complex isolated from the NdCl3 3P350 (or TBP)-Al(i-Bu)3 system. IR and 13C-NMR data show that there is-CH2CH (CH3)2 group at the molecular end of the polydiene. Based on the results, it was proposed that the activce species composition of the Nd-Al bimetallic complex is Nd-CH2CH(CH3)2. The diene polymerization may be in accordance with the process that the monomer inserts into Nd-C bond. A possible diene polymerization mechanism was proposed.