车用聚丙烯材料螺杆脱挥技术的研究

摘要

聚丙烯(PP)中的挥发性有机物(VOC)的释放问题已成为车用PP材料亟待解决的关键问题之一,综合利用螺杆脱挥技术是降低车用材料VOC的有效方法.分别研究了螺杆自然脱挥、螺杆真空脱挥、汽提剂脱挥、脱挥工艺及脱挥设备对PP粉料中VOC种类和VOC总量(TVOC)的影响.实验结果表明,PP粉料和粒料中的VOC均主要由烷烃、烯烃及醛酮类化合物组成,但种类和含量差异较大;利用螺杆自然脱挥、螺杆真空脱挥和汽提剂脱挥技术均可不同程度降低PP的TVOC,但汽提剂脱挥效果最佳;控制螺杆转速可在一定程度上降低TVOC;BUSS捏合机较双螺杆挤出机更有利于PP粉料中VOC的脱除.%Emission of volatile organic compound(VOC) from polypropylene(PP) has become one of the key issues to be solved in PP materials for automobile industry. The screw devolatilizing technology is an effective method to reduce emissions of VOC from PP materials. Effects of technology factors, including screw natural devolatilizing,screw devolatilizing with vacuum,screw devolatilizing with stripping agents,screw speed and processing equipment on both VOC species and the total VOC content(TVOC) of PP powder materials were studied,respectively. The results indicated that VOC components of both PP power and PP pellet were mainly alkanes,olefins,aldehydes and ketones compounds. The number of VOC species and VOC contents between PP power and PP pellet were significantly different. TVOC of PP power could be reduced by screw natural devolatilizing,screw devolatilizing with vacuum and screw devolatilizing with stripping agents. The screw devolatilizing with stripping agents worked most effectively. The TVOC of PP could be reduced by the control of the screw speed. Towards the processing equipment,the BUSS Kneader displayed the more efficient on the reduction of TVOC of PP than the twin screw extruder.