铁体系催化丁二烯聚合动力学研究——(Ⅱ)聚合度与链转移

Kinetic Studies on the Polymerization of Butadiene with Iron Catalyst System Part B——Degree of Polymerization vs·Chain Transfer

本文研究了 Fe(naph)_2-Al(i-Bu)_3—氯化物体系催化丁二烯聚合时的链转移反应。得出只向单体和氯化物链转移的结论,并导出了此体系所特有的聚合度表达式。估算出向单体转移的活化能较低,为41.4KJ/Mol(AlEt_2Cl),12.5KJ/Mol(C_3H_5Cl)。用所得活性链平均寿命τ值的变化,解释了链转移值随温度的升高而加剧。

Chain transfers in the plymerization of butadiene by Fe(naph)_2—Al(i-Bu)_3—Chlorides catalyst system have been investigated.It wasfound that there only exist transfers to monomer and to chloride,and theexpression of degree of plymerization this system possesses was derived.The low activation energy of the transfer to monomer was calculated tobe 41.4 KJ/mol for A1Et_2CI and 52.3 KJ/mol for C_3H_5C1,respectively.Variations of mean life-time of active chain of the system implied thatchain transfers increase with temperature.