干燥方式对高相对分子质量聚丙烯腈结构和性能的影响

The effect of drying methods on the structure and properties of high relative molecular weight polyacrylonitrile

为提高聚丙烯腈(PAN)的性能,获得性能优异的PAN原丝,将^(60)Coγ射线辐照聚合制备的高相对分子质量PAN分别进行真空冷冻干燥、鼓风干燥和真空干燥,通过傅里叶变换红外光谱仪、X射线衍射仪、扫描电子显微镜和热重分析仪对样品进行表征。结果表明:真空干燥会影响PAN的化学结构;升高温度会降低PAN的结晶能力;真空干燥和鼓风干燥使得PAN发生团聚或交联;真空冷冻干燥的PAN粉末热分解性能最稳定,同时溶解性能也最好;真空冷冻干燥为最佳干燥方式。

In order to improve the properties of polyacrylonitrile(PAN)and obtain excellent PAN precursor fibers,high relative molecular weight PAN prepared by ^(60)Co gamma ray irradiation polymerization was subjected to vacuum freeze-drying,blast drying,and vacuum drying,respectively.The samples were characterized by Fourier transform infrared spectroscopy,X-ray diffraction,scanning electron microscopy,and thermogravimetric analysis.The results indicated that vacuum drying could affect the chemical structure of PAN,increasing the temperature reduced the crystallization ability of PAN,and vacuum drying and blast drying caused aggregation or cross-linking of PAN.The thermal decomposition performance of PAN powder obtained through vacuum freeze-drying was the most stable,and the solubility performance was also the best.Therefore,vacuum freeze-drying was the best drying method.