摘要
Two commercial ethylene-propylene random copolymers(A and B) for hot water piping of which A has better long term heat stability and slow crack growth resistance performance than B were fractionated with respect to the isotactity distribution by preparative temperature-rising elution fractionation(TREF).The molecular weight and distribution of fractions and the original resins were investigated by gel permeation chromatography.The results indicated that both A and B had broad isotacticity distribution and A had fewer portions of high isotacticity than B.At the same time A had broader and more typical double-peak molecular weight distribution.The fractions of A had higher molecular weight and broader molecular weight distribution than those of B’s.All of these results implied the differences between the catalysts or the polymerization processes for the two copolymers.
Two commercial ethylene-propylene random copolymers （A and B） for hot water piping of which A has better long term heat stability and slow crack growth resistance performance than B were fractionated with respect to the isotactity distribution by distribution of fractions and preparative temperature-rising the original resins were inves elution fractionation （TREF）. The molecular weight and tigated by gel permeation chromatography . The results indicated that both A and B had broad isotacticity distribution and A had fewer portions of high isotacticity than B. At the same time A had broader and more typical double-peak molecular weight distribution. The fractions of A had higher molecular weight and broader molecular weight distribution than those of B＇ s. All of these results implied the differences between the catalysts or the polymerization processes for the two copolymers.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2006年第1期177-179,共3页
Acta Polymerica Sinica
基金
国家重点基础研究发展规划项目(项目号G1999064800-07)
关键词
丙烯-乙烯无规共聚物
热水管材
TREF
GPC
Random ethylene-propylene copolymer, Hot water piping, Preparative temperature-rising elution fractionation （TREF）, GPC, Fractionation
