不同弹性体对电子废弃物废PP改性效果的影响

针对废PP(聚丙烯)的抗冲击强度降幅明显的问题,分别采用POE(乙烯-辛烯共聚物)和SBS(苯乙烯-丁二烯-苯乙烯嵌段共聚物)作为增韧剂,对废PP共混改性效果进行了研究. 结果表明:POE和SBS均可有效改善废PP的韧性,提高冲击强度；当弹性体用量为15%(以w计,下同)左右时,其共混体系的冲击变化过程由脆性断裂逐渐向韧性断裂转变；添加16.7%的弹性体时,POE和SBS共混体系的冲击强度可分别达到新PP的2.33和1.90倍,但POE对共混体系的冲击性能改善效果更佳. POE较SBS在废PP基体中分布更为均匀,弹性体用量为16.7%时,PP/POE体系熔体流动速率为17.4g/10min,大于PP/SBS体系(6.21g/10min),即PP/POE体系具有加工优势. 但是添加弹性体后,废PP共混体系的拉伸强度、弯曲强度等指标有所下降,需进一步提高. 

Modification Effects of Different Elastomers on Waste PP in E-Waste

Being replaced by new products or abandoned because of low durability, an increasing number of electronic wastes in which the plastic content was approximately 20% in the scrap heap. Considering the polypropylene (PP) would seriously age as the main constitution of the outer casing, which leads to the decrease of mechanical performance without not much value in recycling and utilizing. In the essay, the recycling of waste PP became more qualified by enhancing its strength and toughness. We aimed at the polypropylene (PP) in outer casing of wasted washing-machine. The plastic polypropylene (PP) of waste washing machine shell was set as the research object. The toughness of PP decreased significantly because of the degradation during the process. The study focused on toughness modification of waste plastic aiming to improve the impact strength for its recyclability. Waste polypropylene (PP) was modified by polyolefine elastomer (POE) and styrene-butadiene-styrene block copolymer (SBS) to solve the problem of impact strength declined significantly. POE and SBS were blended with waste PP as toughening agents, while thermal property and mechanical properties of the waste PP were studied. The results showed that the toughness of the waste PP can be improved obviously when POE and SBS was added. The impact fracture process of the waste PP blended toughening agents changed from brittle fracture to ductile fracture with increasing elastomer content. When 16.7% elastomer was added, the impact strength of waste PP/POE and waste PP/SBS was improved 2.33times and 1.90times than new PP's, respectively. In general, impact property of PP/POE can be improved accordingly. POE dispersed more evenly than SBS in waste PP, when 16.7% elastomer was added, melt flowing rate of the waste PP/POE was 17.4g/10min,which is greater than waste PP/SBS. POE dispersed more evenly than SBS in waste PP, impact property and melt flowing rate of the waste PP can be improved accordingly. However, the bending strength of waste PP should be improved in next research. Modified PP could be used for the production of plastics such as the cylinder in the washing machine, and it had reached the standard of impact property. However, it needs to be further studied in improving the tensile strength and bending strength; otherwise, it could not meet the requirements of actual production and provide to related enterprises some technical supports.