聚乙烯/聚丙烯和聚乙烯/聚酰胺复合纤维定性鉴别方法研究

Qualitative identification methods of polyethylene/polypropylene and polyethylene/polyamide composite fibers

采用燃烧法、溶解法、显微镜法、差示扫描量热法(DSC法)以及红外光谱法(FTIR法)对聚乙烯/聚丙烯(PE/PP)复合纤维和聚乙烯/聚酰胺6(PE/PA 6)复合纤维进行了定性鉴别。结果表明:燃烧法中,PE/PA 6复合纤维在燃烧过程中有氨基味,且残留物呈硬淡棕色透明圆珠状,而PE/PP复合纤维燃烧过程中有石蜡味,残留物呈灰白色蜡片状;溶解法较难区分出PE/PP复合纤维和PE/PA 6复合纤维;显微镜法中,两种复合纤维的横截面薄片上,滴加碘-碘化钾溶液,PE/PA 6复合纤维的芯层变深褐色,PE/PP复合纤维的芯层不显色;DSC法和FTIR法中,可根据DSC曲线中的的熔融温度PE(约132℃)、PP(约162℃)、PA 6(约216℃)和FTIR中PE,PP,PA 6的红外特征峰来鉴别PE/PP复合纤维和PE/PA 6复合纤维。

Polyethylene/polypropylene(PE/PP)composite fiber and polyethylene/polyamide 6(PE/PA 6)composite fiber were qualitatively identified by combustion,dissolution,microscopy,differential scanning calorimetry(DSC)and Fourier transform infrared spectroscopy(FTIR).The results showed that the PE/PA 6 composite fiber released amino smell in the combustion process and the residue was of hard light brown transparent bead shape,while the PE/PP composite fiber had paraffin smell and the residue was gray white wax flake;it was difficult to distinguish PE/PP and PE/PA 6 composite fibers by dissolution method;the core layer of PE/PA 6 composite fiber turned dark brown,but that of PE/PP composite fiber did not show color when iodine-potassium iodide solution was added on the cross-section sheet of the two composite fibers in the microscope method;and PE/PP composite fiber and PE/PA 6 composite fiber can be identified based on the melting temperature of PE(about 132℃),PP(about 162℃),PA 6(about 216℃)in DSC curves and the infrared characteristic peaks of PE,PP,and PA 6 in FTIR.