Research on the Thermal Stability of Polyolefin

The aging and degradation of polyolefins is the result of the combination and interaction of many factors, but it is basically classified into three ways: thermal aging, thermal oxidative aging and photooxidative aging. Thermal-oxygen aging and photo-oxygen aging are derived from the dual effects of heat-oxygen and light-oxygen respectively. The essence is that the main chain of the polyolefin is broken due to the influence of heat, light, etc., and the generated polymer radical R is quickly combined with ambient oxygen and converted into a polymer peroxy radical ROO. The second initiation and leading to the automatic oxidation process of polyolefin get on. Generally speaking, thermal oxidative aging and photooxidative aging are the main causes of polyolefin-aging degradation.

In order to achieve the purpose of inhibiting aging and improving the stability of polyolefins, on the one hand, various harmful factors that initiate or promote the aging and degradation of polyolefins (such as the addition of light shielding agents, ultraviolet absorbers, etc.) can be suppressed to the greatest extent, and on the other hand, it can be passed Capture or remove polyolefin radicals R·, peroxy radicals R00· and hydroperoxide ROOH that lead to the oxidative degradation of polyolefins, and cut off the auto-oxidation chain reaction of polyolefins from the mechanism, so that the polyolefins tend to be stable, most of which are high Performance polyolefin stabilizers were developed for this purpose.