采用3种市售β晶型成核剂:芳酰胺类β晶型成核剂NJ star NU-100、TMB-5以及稀土类β晶型成核剂GH-100对自制的丙烯-乙烯无规共聚物(PP-R)进行改性,通过差示扫描量热法(DSC)计算了β晶相对结晶度。结果表明,添加TMB-5后,β晶在PP-R中形...采用3种市售β晶型成核剂:芳酰胺类β晶型成核剂NJ star NU-100、TMB-5以及稀土类β晶型成核剂GH-100对自制的丙烯-乙烯无规共聚物(PP-R)进行改性,通过差示扫描量热法(DSC)计算了β晶相对结晶度。结果表明,添加TMB-5后,β晶在PP-R中形成效果十分显著,尤其是当结晶的冷却速率较低和TMB-5的含量较高时;分别用3种β晶型成核剂对PP-R进行改性,通过计算β晶相对结晶度,得出在相同的结晶条件和含有等量β晶型成核剂的情况下,3种成核剂的β晶成核效率为:NJ star NU-100>GH-100>TMB-5。展开更多
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 th...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.展开更多
文摘采用3种市售β晶型成核剂:芳酰胺类β晶型成核剂NJ star NU-100、TMB-5以及稀土类β晶型成核剂GH-100对自制的丙烯-乙烯无规共聚物(PP-R)进行改性,通过差示扫描量热法(DSC)计算了β晶相对结晶度。结果表明,添加TMB-5后,β晶在PP-R中形成效果十分显著,尤其是当结晶的冷却速率较低和TMB-5的含量较高时;分别用3种β晶型成核剂对PP-R进行改性,通过计算β晶相对结晶度,得出在相同的结晶条件和含有等量β晶型成核剂的情况下,3种成核剂的β晶成核效率为:NJ star NU-100>GH-100>TMB-5。
文摘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.
