CAJ | 학술논문

通过介孔分子筛SBA-15负载半夹心结构有机金属钛(IV)催化剂在一定的反应温度(20～80℃)和1013 kPa乙烯压力下合成了纳米聚乙烯纤维.讨论并比较了负载剂和聚合条件对催化活性、聚合物分子量及聚合物形态的影响.相对于均相催化剂而言,催化活性有所降低,但聚合物分子量明显增大,达到106数量级.在相同压力下,从低温到高温,聚乙烯形态也从细小纤维束逐渐变粗,更高温度熔成片状,80℃以上纤维状形态消失.这些表明,通过外部条件的选择可以得到合适的聚乙烯纤维.
통과개공분자사SBA-15부재반협심결구유궤금속태(IV)최화제재일정적반응온도(20～80℃)화1013 kPa을희압력하합성료납미취을희섬유.토론병비교료부재제화취합조건대최화활성、취합물분자량급취합물형태적영향.상대우균상최화제이언,최화활성유소강저,단취합물분자량명현증대,체도106수량급.재상동압력하,종저온도고온,취을희형태야종세소섬유속축점변조,경고온도용성편상,80℃이상섬유상형태소실.저사표명,통과외부조건적선택가이득도합괄적취을희섬유.
Nanofibrous polyethylene (PE) was prepared via in situ ethylene extrusion polymerization on SBA-15supported titanium(Ⅳ) cyclopentadienyl-aryloxy catalyst under appropriate reaction temperature (20～80 ℃) and ethylene pressure (1013 kPa). The effects of catalyst support and polymerization conditions on catalyst activity,molecular weight and morphology of polymer were investigated. Compared with homogeneous counterpart, the supported catalyst gave a little lower activity, but very high molecular weight (106) polymers were obtained. At lower temperature, the fine PE fibers were displayed. As the polymerization temperature rose, the resultant fiber bundles got thicker,and then gradually congregated into sheet polymers at higher temperature. Above approximate 80 ℃, the fiber morphologies of the polymers disappeared. These changes indicate that morphology of polymers can be regulated by extrinsic factors.