摘要
对TiCl_3及TiCl_4/MgCl_2-Al(C_2H_5)_3(或Al(i-C_4H_9)_3、Al(C_2H_5)_2Cl)催化体系合成的聚辛烯的分子量分布用SchulzeFlory“最可几分布”函数作拟合处理,将各种聚合条件下的实测分布分成了3～5个“最可几分布”的叠加,催化剂结构及聚合条件对这些“最可几分布”峰的位置、大小的影响较有规律,表明每个峰对应于一种活性中心。还测定了聚辛烯各级分的活性中心浓度。对各活性中心的差异作了分析。
The molecular-weight distribution (MWD) graphs of polyoctene-1 synthesized by TiCl3 or TiCl4/MgCl2 with A1(C2H5)3, A1G-C4H9)3 or A1(C2H5)2C1 were accurately fitted with 3-5 Schulz-Flory 'the most probable' distributions of different position and area, and the position and area of the theoretical distributions change regularly with the catalyst and polymerization conditions, showing that each of the 'the most probable' peaks corresponds to a certain kind of active center, and the broad MWD (Mw/Mn=3-12) of the studied polymer is the results of 3-5 kinds of active centers. The plurality of active centers was also evidenced by measuring thenumber of active centers in the polymer fractions of different molecular-weight. The characteristics of different active centers as well as the polymerization mechanism are discussed based on the results of MWD fitting.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第12期1681-1685,共5页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
关键词
催化剂
活性中心
多分散性
分子量
Ziegler-Natta catalyst, Active center, Plurality, Molecular-weight distribution
