Effect of Antioxidants on the Stability of Poly(ether ether ketone) and the Investigation on the Effect Mechanism of the Antioxidants to Poly(ether ether ketone)

Two types of antioxidants (a phenolic antioxidant and a phosphorous antioxidant) were used to improve the stability of poly (ether ether ketone) (PEEK). To evaluate the effect of the antioxidants on the properties of PEEK and the stabilization mechanism, some characterization methods were carried out, such as rheometer, TGA, and electron spin resonance (ESR). The results indicated that the efficiency of the phosphorous antioxidant (DS) in improving the stability of PEEK was better than that of the phenolic antioxidant (DN) and the thermal stability of PEEK sample containing 0.07 wt% DS was the best among all samples due to the decrease of the free radicals density, as proven by ESR measurement. The possible stabilization mechanism of the antioxidants to PEEK was proposed to reveal the reason that caused the different performances of the two types of antioxidants to PEEK.