February 2006
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27 Reads
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5 Citations
Activity, hydrogen response, stereospecificity and kinetic behavior of catalysts with 1, 3-diol dibenzoate as internal donor for propylene polymerization were studied. 1, 3-diol diester-based catalyst ( ND-01) possessed high activity with slow decaying in propylene polymerization. Polypropylene obtained over the catalyst was controllable in stereospecificity with broad relative molecular mass distribution(MWD). Even without any external donors, the isotacticity of polypropylene obtained on 1, 3-diol diester based ND-01 catalyst could reach 94. 2%. The performance of ND-01 catalyst with various external donors were quite different from currently used catalyst A with n-butyl phthalate (DNBP)as internal donor. The hydrogen response behavior of ND-01 catalyst in polymerization with diisopropyl dimethoxy silane (DIPDMS) as external donor was excellent. Because 1, 3-diol diester was more difficult to be extracted from catalyst by triethyl aluminum or triethyl aluminum/cyclohexylmethyl dimethoxy silane (AlEt3/CHMDMS) than di-n-butyl phthalate (DNBP) therefore the loss lessened. The activity of ND-01 catalyst dropped with increasing of precontacting time with AlEt3/CHMDMS.