Influence of polar groups in binary polymer blends on positronium formation

Ramya, P. and Guagliardo, P. and Pasang, T. and Ranganathaiah, C. and Samarin, S. and Williams, J. F. (2013) Influence of polar groups in binary polymer blends on positronium formation. Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 87 (5). ISSN 1539-3755

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Abstract

The present work studied the role of the polar group unconjugated oxygen on the inhibition of positronium (Ps) formation in two binary blends made from a set of chosen constituent polymers with polar and weakly polar groups (nonpolar). The polymer blend samples of PVC-EVA and PVC-SAN were investigated by coincidence Doppler broadening and positron lifetime techniques. The strong polar acetate group in the EVA contributed to positron annihilation with electrons of unconjugated oxygen (–C+=O−) as revealed by the momentum distribution curves peaking around 17 PL (10−3 m0c). The ortho-Ps intensity indicated the unconjugated oxygen shows about a 28% Ps reduction even in the presence of a strong Ps inhibiting halogen (Cl−). In contrast, this effect was not seen in the PVC-SAN blends since SAN contains a weakly polar (nonpolar) acrylonitrile group (C≡N). Our results indicate the chlorine of PVC in the blends is a major contributor to Ps inhibition through the formation of a (Cl−-e+) bound state but the unconjugated oxygen in EVA of the PVC-EVA blend also plays a similar, but lesser, role.

Item Type:	Article
Uncontrolled Keywords:	chemical structure, Polymers, polymer, chemistry, Oxygen, Models, Molecular, oxygen, Binary polymer blends, Polymer blends, Positrons, Chlorine, Chemical, Electrons, electron, chemical model, Computer Simulation, Acetate groups, Binary blends, Coincidence doppler broadening, computer simulation, Momentum distribution curves, Polar groups, Positron lifetime technique, Positronium formation
Subjects:	D Physical Science > Physics
Divisions:	Department of > Physics
Depositing User:	Arshiya Kousar Library Assistant
Date Deposited:	12 Nov 2019 05:46
Last Modified:	12 Nov 2019 05:46
URI:	http://eprints.uni-mysore.ac.in/id/eprint/9618

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