Effect of radiation on the mechanical, morphological and thermal properties of HDPE/rPTFE blends

Blends of high-density polyethylene and recycled polytetrafluoroethylene micronized powder (HDPE/rPTFE), were prepared using a Brabender Plasticorder at 100/0, 90/10, 80/20, 70/30, and 60/40 blend ratio and subjected to electron beam irradiation at doses ranging from 50 to 200 kGy. The effect of rPTFE loading and irradiation on the mechanical, gel fraction, morphological and thermal properties of the HDPE/rPTFE blends were studied. It was found that the addition of the rPTFE micronized powder to the HDPE matrix resulted in a slight deterioration of its mechanical properties due to poor adherence of the rPTFE particles to the HDPE matrix. The addition of rPTFE improved the thermal stability of the blends. However, when these blends were irradiated, there was an 8-10% increase in the tensile strength depending on the blend ratio. SEM images showed that electron beam irradiation has improved the adhesion between rPTFE micronized powder and HDPE matrix. The crystallinity of the rPTFE micronized powder in the blend increased, but it did not affect the latent heat of melting and latent heat of solidifying. Moreover, there was an increase in the storage modulus, loss modulus at 200 kGy and a shift in glass transition temperature toward higher temperatures at 200 kGy.