聚丙烯SP179耐热氧老化性能的研究

STUDY ON THERMAL OXIDATIVE AGING PROPERTIES OFPOLYPROPYLENE SP179

利用差示扫描量热法(DSC)、烘箱老化试验、以及重复加工等3种方法评价不同加量的抗氧剂1010、抗氧剂168对聚丙烯SP179耐热氧老化性能的影响。结果显示:聚丙烯SP179的氧化诱导时间随着抗氧剂总加量的增加而逐渐增大。在烘箱老化试验中,聚丙烯SP179黄色指数变化明显,抗氧剂加量少于3000 mg/kg时,黄色指数随抗氧剂量的增加而减小,随老化时间的延长而逐渐增大;抗氧剂添加量大于3000 mg/kg时,黄色指数随着抗氧剂量的增加而增大,随着热氧老化时间的延长先出现小幅下降之后再逐渐增大。当抗氧剂足够时,重复加工对聚丙烯SP179的黄色指数、熔体质量流动速率(MFR)影响不明显。此外,在SP179滚塑成型中,抗氧剂1010为1000 mg/kg、抗氧剂168为2000 mg/kg的配方最优。

Effect of different dosage of antioxidant 1010 and antioxidant 168 on thermal oxidative aging properties of polypropylene SP179 were evaluated by three methods of DSC,oven aging test and repeated processing.The results showed that oxidation induction time of polypropylene SP179 gradually increased with increase of the total dosage of antioxidant.In the oven aging test,yellow index of polypropylene SP179 changed obviously.When dosage of antioxidant was less than 3000 mg/kg,yellow index decreased with increase of antioxidant dosage,gradually increased with prolongation of aging time;When dosage of antioxidant was more than 3000 mg/kg,yellow index increased with increase of antioxidant dosage,decreased slightly at first and then increased gradually with prolongation of thermal oxygen aging time.When antioxidant dosage was enough,repeated processing had no obvious effect on yellow index and MFR of polypropylene SP179.It was proposed that the antioxidant formulation 1010 and 168 was respectively 1000 mg/kg and 2000 mg/kg in SP179 rotational molding.