Study on poly (ethylene-co-vinyl acetate), acrylonitrile butadiene copolymer, and their blend reinforced with carbon black using position annihilation lifetime spectroscopy. (25th November 2016)

• Record Type: Journal Article
• Authors: Gomaa, E.; Mansour, S. H.; Asaad, J. N.; Aly, E. Hassan
• Is Part Of: Plastics, rubber, and composites. Volume 45:Number 10(2016)
• Page Start: 423
• Page End: 429
• Publication Date: 2016-11-25
• Subjects: PALS -- EVA -- NBR -- Blend -- Free-volume -- HAF -- Composites; Plastics -- Periodicals; Rubber -- Periodicals; Polymeric composites -- Periodicals; Polymer engineering -- Periodicals; 668.9
• DOI: 10.1080/14658011.2016.1242462
• Languages: English
• ISSNs: 1465-8011

Abstract

Abstract : Positron annihilation lifetime spectroscopy (PALS) have been used to investigate the effect of filling each of poly (ethylene-co-vinyl acetate) (EVA), acrylonitrile butadiene rubber (NBR), and their blend (50/50wt-%) with different concentrations of high-abrasion furnace (HAF) (0–60 phr). PALS is characterised by the free-volume parameters ( V h and F %), which is a measure of the size and fraction of free-volume holes in the composites. The results show that the variation in V h and F % of free-volume holes depends on the chemical structure and the degree of crystallinity of each polymer. The NBR has a smaller size (127.78 Å 3 ) and lower fraction (4.18%) of free-volume holes than the corresponding free-volume holes (177.48 Å 3 and 7.03%) in EVA. The size of the free-volume holes increases in EVA with increasing HAF content up to 20 phr in polymer matrix while it decreases in NBR. The fractions ( F %) of free-volume holes decrease due to the reduction in positronium formation in polymer and positron trapping at polymer interface. The results also show an inverse correlation between free-volume parameters ( V h and F %) and tensile strength value, and a direct correlation with elongation at break as a function of HAF content in EVA and NBR. The electrical properties are negatively correlated with lifetime of free positron, τ 2, and positively with its relative intensity ( I 2 ).