聚丙烯粉料乙烯含量测定影响因素研究

Study on influence factors for determination of ethylene content in polypropylene powder

利用外商提供的分析方法和一系列标样样片,建立了无规和抗冲共聚聚丙烯中乙烯含量测定的工作曲线,由于聚丙烯粉料样品结构与性质的不稳定性和不均匀性,决定了实际粉料样品乙烯含量在测试处理上往往不能完全与建立标线处理上的一致。通过选取不同牌号乙丙共聚聚丙烯粉料样品,着重试验分析了热压制样中冷却方式、抗氧剂、样品粒径对粉料乙烯含量测定结果的影响。结果表明,热压制样中冷却方式对粉料乙烯含量的测定结果形成了较为明显的影响;同样粉料样品中是否添加抗氧剂及所加抗氧剂的种类对测定结果也构成了很大程度的影响;另外,粉料样品粒径对乙烯含量的测定结果形成了显著的影响。

A working curve was established for the determination of ethylene content of random and impact copolymerized polypropylene using an analysis methods provided by foreign investors and a series of standard samples. Owing to the instability and heterogeneity in structure and properties of polypropylene powder samples,the ethylene content of actual powder samples is often not completely consistent with the establishment of marking treatment. By selecting different grades of ethylene-propylene copolymer-type polypropylene powder samples,the effects of cooling mode,antioxidant,and particle size of samples on the determination result of ethylene content in hot-pressing sampling were analyzed. The results indicated that the cooling mode generate an obvious effect on the determination of ethylene content in powders during the hot-pressing process. Similarly,there was a significant influence on the determination results resulting from the powder samples with or without antioxidant as well as the antioxidant types. In addition,the particle size of powder samples generated a great effect on the determination results of ethylene content.