不同软段聚氨酯的红外光谱定量分析

Quantitative Analysis of Polyurethane with Different Soft Segments

以异佛尔酮二异氰酸酯(IPDI)为硬段,聚环氧丙烷醚二醇(PPG)和聚己内酯二醇(PCLD)、聚碳酸酯二醇(PCD)、聚四氢呋喃醚二醇(PTMG)为软段,通过改变软段组分及相对含量,合成了系列水性聚氨酯乳液。采用傅立叶自解卷积方法,对合成试样红外光谱的重叠谱带进行分峰处理,结果有效增强了红外谱图的表观分辨率,不仅可以辨认低含量组分的特征吸收,而且当软段含量为4%时仍可检出。采用积分面积法和峰高法进行定量计算并作线性回归分析,发现积分面积法的相关系数r大于0.95。积分面积法优于峰高法。氢键作用对定量结果有一定影响。核磁共振氢谱验证数据与定量分析结果一致。

A series of waterborne polyurethane [ isophorone diisocyanate （IPDI） as hard segment, polypropylene glycol （PPG） and polycaprolactonediol （PCLD） polycarbonatediol （ PCD）, polytetramethylene ether glycol （PTMG） as soft segment] were synthesized through changing the structure and the relative composition of soft segment. Fourier self-deconvolution （FSD） was applied to treat the overlapped peaks in spectra. The results show that FSD can enhance the apparent spectrum resolution and distinguish the content of low composition efficiently. Integrated intensities and peak heights were used for quantitative analysis. Linear regression was applied to get some standard relations to describe the change of soft segment concentration quantitatively. The method of integrated intensity is better than that of peak height. The correlation coefficient of linear rehydrogen is greater than 0.95 and the lowest detectable limit for soft segment is about 4%. It is found that the bond exerts some influences to the accuracy of quantitative analysis. The data are consistent with ^1H NMR analysis results.