聚乙烯/聚丙烃催化合金的组成分析

Analysis of PE/PP in-reactor alloy composition

采用温度梯度萃取分级法(TGEF)将PE/PP催化合金分成5个级分.样品用正辛烷溶解,然后缓慢冷却至室温,溶液经减压浓缩后,用乙醇沉淀得室温级分.将沉淀物用滤纸包好后放入控温萃取仪中,将温度分别控制在100℃,113℃和120℃,各萃取12 h,萃取后的溶液经减压浓缩,用乙醇沉淀过滤,真空干燥至恒重.各级分经红外光谱(FTIR),13C-NMR,DSC,WAXD等分析测试表征,结果显示PE/PP催化合金主要由PE,PP两种均聚物组成,同时还有相当量的乙丙嵌段共聚物.初步分析认为,嵌段共聚物起到PE与PP间相容剂的作用,实现了两种主要组分间性能互补、使得合金具有优异的刚性与韧性.

PE/PP in-reactor alloy were fractionated into five fractions through TGEF（tempera- ture-gradient extraction fractionation）, N-Octane was used as the solvent to successively extract the sample at different controlled temperatures, from room temperature to 120 ℃. Five fractions were collected by extracting 2 g of PE/PP in-reactor alloy at 20 ℃, 100 ℃, 113 ℃, 120 ℃ and〉 120 ℃, respectively. Purified fractions were obtained after concentrating the extract solutions by precipitating, filtering, washing and drying the fractions in vacuum. The fractions were analyzed by FT-IR, ^13C-NMR, DSC, WAXD. According to the above analysis, a conclusion was reached that the PE/PP in-reactor alloy were mainly composed of PE and PP, in addition, a little of dif- ferent sequence length ethylene-propylene blocks. The PP-b-PE as compatibilizer lead to the PE/ PP in-reactor alloy possess high rigid and high toughness.