红外光谱法测定聚丙烯的等规度.pdf

石油化工
20)]4年第43卷第11期
PETROCHEMICAL TECHNOLOGY
红外光谱法测定聚丙烯的等规度
张雅茹,于鲁强,杨芝超
(中国石化北京化工研究院,北京100013)
[摘要」分别在140,160℃:下对聚丙烯试样进行退火预处理,然后基于NMR法得到的聚丙烯等规度,建立了一种用R法快速
测定聚丙烯等规度的方法,并拟合出相关曲线方程,考察了该方法的准确度、精密度和重复性。实验结果表明,在聚丙烯的
IR谱图中,998cm'处的吸光度与973cmr'处的吸光度的比值(Ag4)随退火温度的升高而增大;且试样在160℃下退火后
其AogA4、熔体流动指数的对数与等规度有较好的线性关系。采用R法通过曲线方程得到的等规度与采用NMR法测得的等
规度接近,最大偏差仅为0.4%,重复测定同一试样的最大偏差为0.3%。该方法的准确度和精密度均较高,重复性较好。与采
用索氏萃取法和NMR法相比,采用IR法测定聚丙烯等规度具有分析速度快、操作简便等优点。
关键词!红外光谱法;核磁共振;聚丙烯;等规度;退火预处理
[文章编号]1000-8144(2014)11-1331-05
[中图分类号]TQ320.77
文献标志码]A
Measurement of Polypropylene Isotacticity by Infrared Spectrometry
Zhang Yaru, Yu Lugiang, Yang Zhichao
(SINOPEC Beijing Research Institute of Chemical Industry, Beijing 100013, China
Abstract The polypropylene samples were pretreated by annealing at 140 C and 160 C separately
Based on the isotacticity data observed by NMR method an IR method for polypropylene isotacticit
was established and a curvilinear equation was fitted. The absorbance ratio at the wave numbers
of 998 cm and 973 cm(d/A973)in IR of the polypropylene samples increased with raising the
annealing temperature. It was also indicated that for the samples annealed at 160C, A a/Ag and the
logarithm of melt flow rate showed good linear relationships with the isotacticity. By means of IR, the
isotacticity values calculated by the curvilinear equation were closed to the data obtained by means of
NMR, with the maximum error of 0.4%. When the isotacticity of an identical sample was measured
repeatedly, the maximum error of 0.3% was observed. The IR method showed high accuracy
high precision and good repeatability. Compared with the traditional Soxhlet extraction and NMR
methods, the IR method was rapid and easy to operate
I Keywords J infrared spectrometry; nuclear magnetic resonance; polypropylene; isotacticity;
聚丙烯是一种性能优良的热塑性合成树脂,NMR法。其中,最常用的方法是索氏萃取法?,
广泛应用于电子电器、汽车、建材、医疗、包装但该方法测试周期长,不能迅速反馈到生产环节来
等领域2。聚丙烯的性能与其立构规整度密切相进行参数调整?。NMR法是测试等规度最有效的
关,该立构规整度的评价指标为等规度“。聚丙方法,可检测试样中各个级别的构型序列,但由于
烯的等规度越高,其结晶度越高,产品的硬度、刚
度和模量等机械性能越好,同时熔点、热稳定性和【收稿日期]2014-04-1;に修改稿日期]2014-08-0.
作者简介]张雅茹(1984-),女,山西省长治市人,博十,工
聚丙烯等规度的常用测试方法有索氏萃取法和人:于魯强,电话010-59202618,电邮 yulq jhy@sunapceice2、
耐老化性也相应提高。
程师,电话010-59224932,电邮zhangye.bihy@Sinopec.com。联