Poly(acrylonitrile-co-methyl acrylate) copolymers: Correlation between copolymer composition, morphology and positron annihilation lifetime parameters
Date
2011
Authors
Zengeni E.
Hartmann P.C.
Sanderson R.D.
Mallon P.E.
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Abstract
A series of poly(acrylonitrile-co-methyl acrylate) copolymers of differing copolymer compositions are synthesized through free radical emulsion copolymerisation of methyl acrylate (MA) and acrylonitrile (AN) and by variation of the monomer feed ratios. The copolymers are characterized by NMR, SEC, WAXD, DMA, and positron annihilation lifetime spectroscopy. Results show that, there is a linear decrease in the glass transition temperature (Tg) of the copolymers and the MA content. There is also a progressive decrease in the crystallinity of the copolymers with increasing MA content. Positron results show a sigmoidal variation in the ortho positronium lifetime with an increasing MA content. The low MA content, semi-crystalline copolymers show a positive deviation from the linear additive relationship between the o-Ps lifetime and MA content, whereas the higher MA content amorphous copolymers show a negative deviation from the linear additive behavior. The o-PS intensity shows a linear behavior with MA content with a slight deviation from the additive linear behavior for the very high-content MA copolymer. These variations in the measured positron lifetime parameters are interpreted in terms of the copolymer morphology. © 2010 Wiley Periodicals, Inc.
Description
Keywords
Amorphous copolymers, copolymer composition structural properties, Copolymer compositions, Copolymerisation, Crystallinities, Feed ratios, Glass transition temperature, High-content, Linear behavior, Linear decrease, Methyl acrylates, Negative deviations, o-Ps lifetime, ortho-Positronium lifetime, Positron annihilation lifetime spectroscopy, Positron annihilation lifetimes, Positron lifetime, Semicrystallines, Copolymerization, Copolymers, Electrons, Emulsification, Free radicals, Glass, Morphology, Plastic products, Positron annihilation, Positron annihilation spectroscopy, Structural properties, Temperature, Glass transition
Citation
Journal of Applied Polymer Science
119
2
119
2