摘要
Ethylene-propylene copolymers were synthesized using a TiCl4/MgCl2/SiO2/diester type supported Ziegler-Natta catalyst with or without the presence of hydrogen in a slurry polymerization process.The copolymer was inhomogeneous in composition and can be fractionated into two parts, fractions soluble and insoluble in n-octane at room temperature, respectively.The soluble part is a nearly random copolymer,while the insoluble part is a kind of segmented copolymer,as revealed by 13 C-NMR and DSC analyses.Adding H2 in the reaction system caused an increase of copolymer yield and a decrease of the insoluble part,but the propylene content and average length of propylene segments of the insoluble part were markedly increased,meanwhile the average length of ethylene segments of the insoluble part was markedly decreased.Copolymer sequence distribution of the soluble part was only slightly changed by H2. The segmented copolymer fraction present in this ethylene-propylene copolymer has the similar structure as the segmented copolymer fractions found in polypropylene/poly（ethylene-co-propylene） reactor alloy.Mechanism of the hydrogen effect on copolymer structure is discussed.
Ethylene-propylene copolymers were synthesized using a TiC14/MgCl2/SiO2/diester type supported Ziegler-Natta catalyst with or without the presence of hydrogen in a slurry polymerization process. The copolymer was inhomogeneous in composition and can be fractionated into two parts, fractions soluble and insoluble in n-octane at room temperature, respectively .The soluble part is a nearly random copolymer, while the insoluble part is a kind of segmented copolymer, as revealed by ^13 C-NMR and DSC analyses. Adding H2 in the reaction system caused an increase of copolymer yield and a decrease of the insoluble part, but the propylene content and average length of propylene segments of the insoluble part were markedly increased, meanwhile the average length of ethylene segments of the insoluble part was markedly decreased. Copolymer sequence distribution of the soluble part was only slightly changed by H2. The segmented copolymer fraction present in this ethylene-propylene copolymer has the similar structure as the segmented copolymer fractions found in polypropylene/poly（ethylene-co-propylene） reactor alloy. Mechanism of the hydrogen effect on copolymer structure is discussed.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2006年第4期632-635,共4页
Acta Polymerica Sinica
基金
国家重点基础研究专项经费(基金号2005CB623804)资助项目
关键词
乙丙共聚物
负载型Z-N催化剂
氢气
链结构
Ethylene-propylene copolymer, Supported Z-N catalyst, Hydrogen, Chain structure
