超声处理在聚丙烯腈溶解中的作用

利用超声波的空化效应强化溶解聚丙烯腈(PAN),通过旋转黏度计测量溶液黏度,并与常规搅拌溶解进行对比,证明了超声处理有加速溶解进程以及降低溶液黏度的作用,但经过超声强化溶解的溶液静置后黏度值增速较快,溶解完毕的溶液不宜久置。同时研究了超声波对PAN分子量及分子量分布的影响,由GPC测试结果得出长时间超声处理会降低其相对平均分子量,并且分子量分布变宽。对PAN的超声处理进行了Matlab建模分析,构建适用于PAN溶解体系的泡核壁运动模型,分别计算了超声频率、环境压力、表面张力和溶液黏度对泡核运动的影响,指出溶液黏度是影响超声效果的主要因素。

Effect of ultrasonic treatment in polyacrylonitrile dissolution

Polyacrylonitrile (PAN) was dissolved by the cavitation effect of ultrasonication, and the viscosity of the solution was measured using rotational viscometer, and was compared with the conventional solution by stirring. Ultrasonic treatment could accelerate the dissolution process and reduce the viscosity of the system, which were based on the transformation of the swelling method. The influence on polymer chain structure of ultrasonic was also investigated. Longtime ultrasonic treatment could reduce the relative average molecular weight, and a broader molecular weight distribution was observed. A modeling analysis was built for the ultrasonic treatment of PAN by Matlab. The motion model of vacuole nuclei suitable for the PAN dissolution system was constructed. The influences of the main factors, such as ultrasonic frequency, ambient pressure, surface tension and viscosity were calculated. Viscosity played a vital role in the effect of ultrasonicat