Radiation Effects in Acrylonitrile (AN) Ethyl Methacrylate Copolymer by Spectroscopic and Thermal Methods

Abstract

Gamma irradiation effects in acrylonitrile (AN) ethyl methacrylate (EMA) (AE) copolymer have been investigated by electron spin resonance (ESR), Fourier transform infrared (FTIR) and differential scanning calorimetric (DSC) techniques. Temperature and radiation dose dependent effects have been investigated by recording ESR spectra under different conditions. Computer simulation techniques are used to analyze ESR spectra to identify of free radical produced on irradiation of copolymer. As such, ESR spectrum of irradiated copolymer at RT is simulated to be a super position of component spectra arising due to ~CH₂-Ċ (CN)-CH₂(I) COOC₂H₅ (II) free radicals. The ESR spectrum is found stable up to an elevated temperature of 487 K indicating that the free radicals are thermally stable. Intensity of ESR spectrum increased with the increase of radiation dose indicating formation of more number of free radicals. Chemical changes induced by gamma irradiation have been studied by comparing the FTIR spectra of non-irradiated and irradiated copolymer. The results suggest that the ester groups are found to be prone to irradiation; while acriylonitrile groups are unaffected by gamma irradiation. DSC, thermogram of copolymer consists of a first order transition at 88°C corresponding to the T_g of copolymer, while exothermic peak is observed at 285°C. On irradiation, both the peaks shifted to lower temperatures. 

Cite this Article

Suresh D, Sanjeeva Rao B, Kalahasthi S et al. Radiation Effects in Acrylonitrile (AN) Ethyl Methacrylate Copolymer by Spectroscopic and Thermal Methods. Journal of Polymer & Composites. 2017; 5(3): 22–29p.