Study On Polypropylene Of Thermal Oxygen Aging Properties

Polypropylene(PP) is a kind of superior polyolefin. It has good themal stabilily and difficult degradation under anaerobic conditions, But it is liable to degrade for its tertiary hydrogen. So the research of PP oxygen degradation had the positive significance on the application of the PP.Studied the mechanism of thermal oxidative aging of PP, The results showed that the degradation kinetics process was including " induction period stage " and " speed change stage ". And it obeyed exponential growth.Studied the effect of different kinds of antioxidants on the processing stability of polypropylene. The results showed that compared with antioxidant 1010 along with antioxidant 626 or DSTP, the antioxidant 1010 compounded with antioxidant 168 had a good effect. When mixture ratio was 1:2, antioxidant 3125 compounded with antioxidant168 could have a better effect than with other antioxidants. But when mixture ratio was 1:1,the effect was fairly. When mixture ratio was 2:1, antioxidant 3125 compounded with antioxidant DSTP was better than with other antioxidants. To study the antioxidants effect on long-term thermal oxidation stability of PP, the results indicated that when antioxidant1010 and antioxidant 168 compounded with the ratio of 1:2, it showed better thermally stable property. Similarly, when antioxidant 3125 and antioxidant 168 compounded with the ratio of 1:1, it also had better effect than with other antioxidants.Research the influence of nucleating agent HPN-68 L on the crystallization behavior and the stability of PP. The results showed that adding the nucleating agent HPN-68 L, it could expedite the crystallization rate, and improve the thermal oxidative ageing properties of PP.Using infrared spectroscopy to analyze the antioxidant in PP, it could get the quantitative standard curves. The results showed that, the correlation coefficient of each standard curve reached above 0.98, and the relative error was less than 6 %. they had high degree of confidence and they could rearch the industrial requirement.