摘要
研究了助催化剂种类(三甲基铝、三异丁基铝、三正己基铝、三乙基铝和甲基铝氧烷)及其含量对无内、外给电子体的TiCl4/MgCl2催化剂催化丙烯高温(100℃)聚合性能的影响,并用结晶分级分析、示差扫描量热和凝胶渗透色谱等方法分析了所得聚丙烯的结晶熔融行为和微观结构。实验结果表明,聚合温度从70℃升至100℃时,TiCl4/MgCl2催化剂的定向能力基本不变;100℃聚合时,以烷基化能力较弱的三异丁基铝为助催化剂时TiCl4/MgCl2催化剂的活性最高,而采用烷基化能力最强的三甲基铝为助催化剂时TiCl4/MgCl2催化剂的活性最低;100℃聚合时,助催化剂的种类对TiCl4/MgCl2催化剂的定向能力影响很小。
Effects of various cocatalysts, namely trimethylaluminium （ Me3Al ）, tdethylaluminium （ Et3 Al）, tdisobutylaluminium （ i-Bu3 Al）, trihexylaluminium （ Hex3 Al） and methylaluminoxane （ MAO ） on performance of donor-free TiCl4/MgCl2 catalyst for propylene polymerization at 100℃ were studied. The obtained polymers were characterized by means of crystallization fractionation, DSC and GPC. Activity of TiCl4/MgCl2 catalyst is the highest with i-Bu3Al as eocatalyst and lowest with Me3Al. Isotacticity of obtained polypropylene keeps constant basically as polymerization temperature increases from 70℃ to 100v with TiCl4/MgCl2-Et3Al catalyst system. The mole ratio of high isotactic fraction of obtained polymer to moderate isotactic fraction varies from 3.7 to 5.6 when different tfialkylaluminiums are used as cocatalysts. Effect of various cocatalysts on isospecificity of TiCl4/MgCl2 catalyst can be neglected when propylene polymefizes at 100℃.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2007年第1期31-34,共4页
Petrochemical Technology
关键词
聚丙烯
丙烯
氯化镁
氯化钛
烷基铝
助催化剂
聚合
催化
polypropylene
propylene
magnesium chloride
titanium chloride
alkylalurninum
cocatalyst
polymerization
catalysis
