无规共聚聚丙烯管材树脂的结构与生产工艺分析

Structure and Process Analysis of Random Copolymer Polypropylene Pipe Resin

采用升温淋洗仪(A-TREF/P-TREF)、核磁共振仪、高温凝胶色谱等研究了某牌号无规共聚聚丙烯(PPR)管材树脂及其异常料和市售料的结构。结果表明,制备型升温淋洗分级(P-TREF)得到6个组分,且都为典型的乙烯-丙烯无规共聚结构,随着淋洗温度的升高,乙烯摩尔分数由26.25%降至2.63%,平均乙烯序列长度变化不大为1.00～1.46,平均丙烯序列长度由4.10增长至38.50,丙烯链段结晶能力不断提高,相对分子质量呈现增加趋势。异常料含有较多低相对分子质量组分。生产工序优化后,消除了异常料,优化后树脂相对分子质量与市售料相近。

The structure of a grade of random copolymer polypropylene pipe resin(PPR), its anomalous materials and one commercially available material was studied by TREF(A-TREF/P-TREF), nuclear magnetic resonance spectrometer, and high-temperature gel chromatography. The results show that the P-TREF shows six components, and all of them have typical ethylene-propylene random copolymerization structures. With the increasing temperature, the ethylene mole fraction decreases from 26.25% to 2.63%.The average ethylene sequence length change is not much,1.00~1.46, and the average propylene sequence length increased from 4.10 to 38.50, and the propylene segment crystallization capacity continues to increase, and the relative molecular mass shows an increasing trend. Abnormal materials contain more components of low molecular weight. After the optimization of the production process, the abnormal materials are eliminated, and its relative molecular mass is similar to that of the commercially available materials.