Author(s)

Anton Atanassov Apostolov

Laboratory on Structure and Properties of Polymers, Faculty of Chemistry and Pharmacy, University of Sofia, Sofia, Bulgaria.

The purpose of the current study is to evaluate the ageing of poly(ethylene-co-propylene) fittings produced by several manufacturers. The fittings were aged for varying times as follows: 0, 2, 13, 23, 45, 106, 225 and 391 days at 100°C. In a previous paper, the oxidation induction time (OItime) and oxidation induction temperature (OItemp) were evaluated with respect to every single step of the ageing process [1]. Here, the Vickers microhardness and wide-angle X-ray line width were used for characterization of the oxidative stability of poly(ethylene-co-propylene) pipes. Both the Vickers microhardness and wide-angle X-ray line width as evaluated from a certain reflex of the diffractogram generally increase with ageing for most samples. The higher microhardness is most likely related to higher fragility of the pipes. The increase of the X-ray line width with ageing indirectly proves that reducing the crystallite size as well as increase of the crystallite defectiveness take place.

Poly(ethylene-co-propylene), Ageing, Microhardness, X-Ray Line Width

Apostolov, A. (2019) On the Vickers Microhardness and Wide-Angle X-Ray Line Width for Characterization of the Oxidative Stability of Poly(ethylene-co-propylene) Pipes. Materials Sciences and Applications, 10, 25-32. doi: 10.4236/msa.2019.101003.