利用拉曼光谱检测丙烯共聚物的性质

采用拉曼光谱检测了7个丙烯共聚物样品，并详细分析了谱图中所有特征峰来源;最终选择2 700～3 100 cm-1作为特征谱段，采用偏最小二乘(PLS)回归的方法分别建立了样品中二甲苯可溶物、乙烯含量及可溶物中乙烯含量与拉曼特征峰相对强度的关联模型。通过预测模型求得的预测含量与真实含量的相关系数(r)均大于0.94，平均相对误差(ARE)均小于5%。还对2 700～3 100 cm-1区域拉曼光谱的第二项PLS成分进行了研究，发现采用PLS回归能够准确、有效地提取出样品的原有信息。为采用拉曼光谱在线检测共聚聚丙烯中的二甲苯可溶物量、乙烯含量及可溶物中的乙烯含量提供了可能性。

Measurement of Properties of Polypropylene Copolymers by Raman Spectrum

Fourier-transform (FT) Raman spectra were measured for 7 kinds of different polypropylene copolymers and the assignments of all Raman bands were made through a detailed analysis. Ultimately, by choosing 2 700~3 100 cm-1 as the characteristic spectral, partial least squares (PLS) regression models were set up for xylene solubles content, ethylene content and ethylene content of xylene solubles in polypropylene copolymers. The values of correlation coefficient (r) between predicted results and actual values were all greater than 0.94, and the values of average relative error (ARE) were all less than 5%. The second PLS factor was also analyzed in this paper, and it was concluded that the original information of the sample was accurately extracted by using PLS regression. This paper offered a kind of possibility for on-line measurement of xylene solubles content, ethylene content and ethylene content of xylene solubles in polypropylene copolymers.