Influence of methylaluminoxane and alkylaluminiums on propylene polymerization at high temperature with TiCl_4/MgCl_2/diether catalysts

摘要

A study of the effect of methylaluminoxane and alkylaluminiums on propylene polymerization at high temperature in the use of a TiCl_4/MgCl_2/9,9-bis(methoxymethyl)fluorine catalyst has shown that,the catalyst showed a high isospecificity and high activity with the commercial methylaluminoxane (MAO) at 100degC.However,the catalyst was inactive with the "TMA-depleted" MAO (MMAO) that contained no or very little free TMA.It showed a high isospecificity and high activity after addition small amounts of alkylaluminiums to MMAO.The results implied the addition of small amounts of alkylaluminiums would disrupt the strong interaction between MAO and titanium species and form separated ion pairs active for olefin insertion.