Chinese Academy of Sciences

Shihui Li

Dongmei Cui

Dongtao Liu

Xinli Liu

Bo Tong Liu

Lingfang Wang

Chunji Wu

Wei Gao

Zhichao Zhang

The invention provides a metal alkoxide complex of Formula (I), wherein X, M, R1, R2, R3, m, n, y and z are as defined in the Description. The invention also provides a catalyst composition comprising the metal alkoxide complex and a hydroxy-containing compound, wherein the molar ratio of the metal alkoxide complex to the hydroxy-containing compound is 1:0.1-1000. The invention also provides a production method of poly-&#x3b5;-caprolactone or polyactide, wherein an &#x3b5;-caprolactone monomer or a lactide monomer is reacted in the presence of the metal alkoxide complex or catalyst composition to obtain poly-&#x3b5;-caprolactone or polylactide. The metal alkoxide complex and the catalyst composition thereof can be used to catalyze the synthesis of poly-&#x3b5;-caprolactone or polylactide with a high efficiency. The molecular weight of polycaprolactone or polylactide can be controlled by the molar ratio of the metal alkoxide complex and the hydroxy-containing compound, and is adjustable in the range of 1000-600,000, and wherein the molecular weight distribution is from 1.03 to 1.50.[XM(OCRRR)].(organic solvent)&#x2003;&#x2003;(I)

Metal alkoxide complex, catalyst composition, and production method of polycaprolactone or polylactide

An isoprene or butadiene cis 1,4-selective polymerization catalyst system together with its polymerization method is provided. This catalyst system is composed of NCN-imine pincer type rare earth metal complex of formula [2,6-(CH&#x2550;N&#x2014;R)-4-R-1-CH]LnX(THF)and alkylating reagent. In an hydrocarbon solvent or under bulk conditions, at a polymerization temperature in a range of &#x2212;20-120&#xb0; C., the conjugated diene is polymerized by using the catalyst system, to produce polyisoprene and polybutadiene having controllable number-average molecular weight, molecular weight distribution of 3.0 or less than, and cis 1,4-content of 95% or more, even 99% or more. The crude rubber and vulcanized rubber of the polyisoprene have high strength, stretching crystallization capability and transparency.

Bi-component catalyst system for isoprene or butadiene cis 1, 4-polymerization and polymerization process

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Jilin, China

Shihui Li