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کاتالیزور کاربردی a: عمومی 2012
جزئیات رویداد
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همایش ، رویداد ، ژورنال
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  • functionalized multi-walled carbon nanotubes with stereospecific ziegler-natta catalyst species: towards facile in situ preparation of polypropylene nanocomposites

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    • تاریخ ارائه: 1392/07/24
    • تاریخ انتشار در تی پی بین: 1392/07/24
    • تعداد بازدید: 1030
    • تعداد پرسش و پاسخ ها: 0
    • شماره تماس دبیرخانه رویداد: -
     multi-walled carbon nanotubes (mwcnts) were functionalized with a stereospecific ziegler-natta catalyst species for in situ preparation of polypropylene (pp)/mwcnt nanocomposites. the functionalization process involved initially treating mwcnts containing a few (∼3.0% w/w) surface hydroxyl groups (mwcnt-oh) with an excess amount of grignard reagent followed by further reaction with ticl4. triethylaluminum (tea) and dimethoxydiphenylsilane (dds) were used as co-catalyst and external electron donor, respectively. the resulting mwcnts (mwcnt/mg/ti) only behaved as a fair isospecific ziegler-natta catalyst, promoting propylene polymerization at a moderate rate and resulting in pp with moderate isotacticity indices (76.4–91.0%). to improve the catalytic performance, the electron-donating reagent 9,9-bis(methoxymethyl)fluorine (bmmf) was added into the mwcnt functionalization process, incorporating bmmf into the catalytic material and simultaneously reducing the quantity of ticl4 immobilization. the bmmf-incorporated functionalized mwcnts (mwcnt/mg/bmmf/ti) produced pp with a high isotacticity index (92.0%) without the use of an external electron donor. pp with an isotacticity index greater than 98% was achieved when dds was used as external electron donor during the polymerization process.

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