干冷技术制样在聚丙烯T30S等规指数测定中的应用

Application of Dry-cooling Technique in Sample Preparation of Polypropylene T30S Isotactic Index Measurement

按GB/T 2412—2008方法测定聚丙烯T30S等规指数,制样时需要使用液氮,操作不当易致人冻伤;并且粉碎后的样品极易黏附在粉碎机的内壁上,易造成样品损失,很难得到代表性很好的试样。采用干冷技术制样,可以消除这些问题,且不影响分析结果的准确性,两种制样方法得到的试样所测得的等规指数偏差均小于1%。利用t检验法比较两种制样方法的差异性,结果表明,两种制样方法之间不存在显著性差异。

According to measurement method in GB/T 2412-2008, the measurement of polypropyl ene T30S isotactie index has to use liquid nitrogen for sample preparation. But liquid nitrogen may cause cold injury if it is not properly handled, furthermore, by this method the ground sample is very easy to adhere to the inside wall of grinding machine to cause sample lose and bad representative ness. The application of drycooling technique in the sample preparation has eliminated these prob lems and ensured the accuracy of the analysis. The result showed the deviation in polypropylene T30S isotactic index measurement between two methods is less than 1%. Ttest was applied to com pare the difference of the two methods and no significant difference was observed by two methods of using different sample making techniques