管材专用高密度聚乙烯的热分级研究

摘要

The crystallization and melting behavior of special high density polyethylene (HDPE) resin for PE100 grade pipes were studied with differential scanning calorimetry (DSC) and successive self-nucleation and annealing (SSA) method. Three HDPE grades were marked with and ranked in sample No.l, sample No.2 and sample No.3, a descending order in accordance with the content of 1-hexene comonomer. The results show that the crystallinity and melting temperature ascend in the same ranking of sample No.l, sample No.2 and No.3 and the values get higher after SSA treatment. The short chain branches decrease gradually in the same sequence of sample No.l, sample No.2 and sample No.3. Among the three specimens, sample No.3 exhibits the highest stiffness and lower toughness, whereas sample No.l has the poorest stiffness and the higher toughness.%利用差示扫描量热法和连续自成核退火分级(SSA)法研究了PE100级管材专用高密度聚乙烯(HDPE)树脂的结晶熔融行为,三个牌号HDPE树脂的1-已烯共聚单体含量按试样1、试样2、试样3逐渐降低.结果表明:两种方法得到的结晶度和熔融温度均按试样1、试样2、试样3递增,且SSA处理后试样的结晶度和熔融温度较高；短链支化度按试样1、试样2、试样3逐渐降低；试样3表现出最佳的刚性和较低的韧性,而试样1则相反.