PVC塑料中碳酸钙填料含量的分析方法

Analysis Method of Calcium Carbonate Filler Content in PVC Plastics

建立一种分析聚氯乙烯(PVC)塑料中碳酸钙填料含量的方法。通过扫描电镜(SEM)-能谱(EDS)法和红外光谱(FT-IR)法分别对不同含量碳酸钙的PVC/碳酸钙样品进行分析。采用EDS软件的半定量分析模块得到Ca、Cl元素相对比例,计算其均值、标准偏差和相对标准偏差,采用Origin软件绘制Ca、Cl元素相对比例与碳酸钙-PVC质量比的点线图,并进行线性拟合,得到校准曲线方程和线性相关系数;采用FT-IR软件定量分析模块建立碳酸钙含量的定量分析方法,得到碳酸钙含量与积分区域峰面积的线性方程。结果表明:通过SEM-EDS法建立的校准曲线呈现良好的线性关系,满足定量分析要求;相比FT-IR法,SEM-EDS法所需样品量少,更适合微量和痕量PVC塑料物证中碳酸钙含量的分析。

An analytical method for the content of calcium carbonate filler in polyvinyl chloride(PVC)plastics was established.PVC/calcium carbonate samples with different contents of calcium carbonate were analyzed by scanning electron microscopy(SEM)-energy dispersive spectroscopy(EDS)and Fourier transform infrared spectroscopy(FT-IR).The relative proportion of Ca and Cl elements was obtained by the semi-quantitative analysis module of EDS software,and the mean value,standard deviation and relative standard deviation were calculated.The dotted line diagram of the relative proportion of Ca and Cl elements and the mass ratio of calcium carbonate to PVC was drawn by Origin software,and linear fitting was performed to obtain the calibration curve equation and linear correlation coefficient.The quantitative analysis method of calcium carbonate content was established by using the quantitative analysis module of FT-IR software,and the linear equation between calcium carbonate content and peak area of the integral region was obtained.The results show that the calibration curve established by SEM-EDS method shows a good linear relationship and meets the requirements of quantitative analysis.Compared with FT-IR method,SEM-EDS method requires less samples and is more suitable for the analysis of calcium carbonate content in trace PVC plastic evidence.