耐划伤剂对车用聚丙烯材料耐划伤和散发性能的影响

采用熔融共混挤出的方法,制备了聚丙烯/滑石粉/弹性体三元共混材料,并考察了两种耐划伤剂对材料耐划伤性能、散发性能和力学性能的影响。采用十字划伤仪和色差仪对材料在常温和热老化(102℃,168 h)条件下的耐划伤性能进行了评价;采用气味评定、顶空–气相色谱、挥发性有机化合物(VOC)袋子法以及雾度仪分别对添加两种耐划伤剂后材料的气味、总挥发性有机化合物(TVOC)以及VOC和雾度进行了测试。结果表明,采用酰胺类和有机硅类耐划伤剂可改善聚丙烯材料表面的耐划伤性能,常温下两者效果相当,但热老化后前者耐划伤性能消失,而后者仍具有良好的耐划伤性能。在散发性能方面,采用有机硅类耐划伤剂在气味等级、VOC、雾度等方面均优于酰胺类划伤剂。相对于酰胺类耐划伤剂,添加有机硅类耐划伤剂的材料韧性和熔体流动速率有所提升。通过使用有机硅类耐划伤剂制备了在耐划伤性能和散发性能上均满足材料要求的汽车零部件。

Effects of Anti-scratch Additives on Scratch Resistance and Emission Lever of Polypropylene Composite for Automobile

Polypropylene (PP)/talc/elastomer ternary composite was prepared via melt extrusion. Two different anti-scratch additives were studied regarding to their effect on scratch resistance,emitting properties and mechanical properties of the composite. Anti-scratch properties of the PP,was evaluated with crosscut machine and colorimeter,after the specimens were conditioned under two different conditions,namely room temperature and thermal aging condition (with a temperature of 102℃ for 168 h). Emitting properties of the composites with the two anti-scratch additives,were discussed,ranging from odor,TVOC,VOC to fogging,by the means of odor evaluation,headspace gas chromatography,bag method for VOC test and fogging evaluation machine. It is discov-ered that both amides and organic silicone anti-scratch additives are efficient to improve the surface scratch resistant characteristic of the composite specimens,which are stored under room temperature. However,regarding to the thermal aging storing condition, the former additive loses its anti-scratch improving function while the latter still works well. In the terms of emitting properties, the organic silicone additive performs better than the amides in odor,VOC as well as fogging tests. Compared with the amides,the toughness and melt flow rate of the composite with the organic silicone additive are improved. Through the work,an automotive PP material modified with the silicone anti-scratch additive is prepared,which can meet the scratch resistant and emitting requirements of a specified vehicle part.