Influence of gamma-ray irradiation on optical and thermal degradation of poly (ethyl-methacrylate) (PEMA) polymer

S. Fares

National Center for Radiation Research and Technology (NCRRT), AEA, P.O. 29 Nasr City Egypt.

DOI: 10.4236/ns.2012.47067                

Abstract

Polymer based on (polyethyl-methacrylate) (PEMA) were exposed to different doses of gamma radiation up to 100 kGy and the physical properties have been studied. The effects of gamma irradiation on the optical spectrum of PEMA films have been investigated using spectrophotometric measurements of reflectance and transmittance in the wavelength range 200-1100 nm. The structure of the sample is analyzed by X-ray diffraction technique and is found to be amorphous and partially crystalline. TGA studies revealed that the thermal stability of polyethyl methacrylate, improved after irradiation doses up to 100 kGy. On other hand driving absorption coefficient α(ω), consequently the band tail width E_e and optical band gap estimated. This behavior is believed to be associated with the generation of excess of electronic localized states. Also, Optical constants such as refractive index (n), extinction coefficient (K) have been determined using Swanepole method. Optical dispersion parameters and the dispersion parameters, such as E_o (single–oscillator energy), E_d (dispersive energy) are discussed in terms of the single-oscillator Wemple-DiDomenico model.

Keywords

Gamma Radiation; PEMA; X-Ray Diffraction Technique; Optical Parameters;Dispersion Parameters; TGA Thermogravimetric

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Paul, S. (1996) Surface coatings science and technology. Wiley, New York, 312.
[2]	Odian, G. (1991) Principles of polymerization. John Wiley & Sons Inc., New York, 311-313.
[3]	Shetter, J.A. (1963) Effect of stereoregularity on the glass temperatures of a series of polyacrylates and polyme- thacrylates. Journal of Polymer Science, B, 1, 209-213. doi:10.1002/pol.1963.110010503
[4]	Hata, T., Nose, T. and Polym, J. (1967) Stress-strain-time relation of poly(n-alkyl methacrylates) in rubbery state. Science, C, 16, 2019.
[5]	Gardlund, Z.G., Laverty, J.J. and Polym, J. (1969) Polyal- kylmethacrylate films as matrices for photochromic studies. Science, B, 7, 719.
[6]	Grassie, N., Mc Callum, J.R. and Polym, J. (1964) Thermal and photochemical degradation of poly(n-butyl methacrylate. Science, A, 2, 983.
[7]	Smith, S.D., Long, T.E. Mc Grath, J.E. and Polym, J. (1994) Thermogravimetric analysis of poly(alkyl methacrylates) and poly(methylmethacrylate-g-dimethyl siloxane) graft copolymers. Science-Chemistry A, 32, 1747.
[8]	Malhotra, S.L., Minh, L., Blanchard, L.P. and Macromol, J. (1983) Thermal decomposition and glass transition temperature of poly-(phenylmethacrylate) and poly (cyclohexyl methacrylate). Science-Chemistry A, 19, 559.
[9]	Ahmed, M.T. (2010) Relaxational study of poly(ethylmthacrylate) by thermally stimulated depolarization current, thermal sampling spectroscopy: modified dipole- dipole interaction theory. Journal of the Korean Physical Society, 57, 272-281. doi:10.3938/jkps.57.272
[10]	Maitra, S., Bandyopadhyay, N., Das, S., Pal, A.J. and Pramanik, J. (2007) Non-isothermal decomposition kinetics of alkaline earth metal carbonate. Journal of the American Ceramic Society, 90, 1299-1303. doi:10.1111/j.1551-2916.2007.01607.x
[11]	Friedman, H.L. (1964). Kinetic of thermal degradation of char-forming plastics from thermogravometry. Application to a phenolic plastic. Journal of Polymer Science Polymer Symposium, 6, 183-195. doi:10.1002/polc.5070060121
[12]	Nam, J.D. and Seferis, J.C. (1991) Composite methodology for multistage degradation of polymer. Journal of Polymer Science: Part B, Polymer Physics, 29, 601-608. doi:10.1002/polb.1991.090290509
[13]	Anderson, D.A. and Freeman, E.S. (1961) The kinetics of thermal degradation of polyethylene and polystyrene. Journal of Polymer Science, 54, 253-260. doi:10.1002/pol.1961.1205415920
[14]	Radhakrishnan, T.S. (1999) New method for evaluation of kinetic parameters and mechanism of degration from pyrolysis—GC studies: Thermal degradation of polydimethylsiloxanes. Journal of Applied Polymer Science, 73, 441-450. doi:10.1002/(SICI)1097-4628(19990718)73:3<441::AID-APP16>3.0.CO;2-J
[15]	Fink, D., Ed. (2004) Fundamentals of ion-irradiated polymers. Springer-Verlag, Berlin, 7-84.
[16]	Sharma, T., Aggarwal, S., Kumar, S., Mittal, V.K., Kalsi, P.C. and Manchanda, V.K. (2007) Effect of gamma irradiation on the optical properties of CR-39 polymer. Journal of Materials Science, 42, 1127-1130. doi:10.1007/s10853-006-0516-7
[17]	Abiona, A.A. and Osinkolu A.G. (2010) Gamma-irradiation induced property modification of polypropylene. International Journal of Physical Science, 5, 960-967.
[18]	Zaki, M.F. (2008) Gamma-induced modification on optical band gap of CR-39 SSNTD. Brazilian Journal of Physics, 38, 558-562. doi:10.1590/S0103-97332008000500005
[19]	Fink, D., Chung, W.H., Klett, R., Schmoldt, A., Cardoso, J., Montiel, R., Vazquez, M.H., Wang, L., Hosoi, F., Omichi, H. and Goppelt-Langer, P. (1995) Carbonaceous Clusters in irradiated polymers as revealed by UV-Vis spectrometry. Radiation Effects and Defects in Solids, 133, 193-208. doi:10.1080/10420159508223990
[20]	Nair, C.P.R., Bindu, R.L. and Joseph, V.C. (1995) Cyanate esters based on cardanol modified-phenol-formal- dehyde resins: Syntheses and thermal characteristics. Journal of Polymer Science, Part A: Polymer Chemistry, 33, 621. doi:10.1002/pola.1995.080330403
[21]	Tang, W., Li, X.G. and Yan, D. (2004) Thermal decomposition kinetics of thermotropic copolyesters made from trans-p-hydroxycinnamic acid and p-hydroxybenzoic acid. Journal of Applied Polymer Science, 91, 445-454. doi:10.1002/app.13103
[22]	Nouh, S.A., Atta, M.R. and El-Melleegy Rad, W.M. (2004) A study of the effects of gamma and laser irradiation on the thermal, optical and structural properties of CR-39 nuclear track detector. Radiation Effects and Defects in Solids, 159, 461-474. doi:10.1080/10420150412331296835
[23]	Kalsi, P.C., Mudher, K.D.S., Pandey, A.K. and Iyer, R.H. (1995) Thermal studies on unirradiated and γ-irradiated polymer of allyl diglycol carbonate. Thermochimica Acta, 254, 331-336. doi:10.1016/0040-6031(94)01989-T
[24]	Mallikarjun, K.G. (2004) Thermal decomposition kinetics of Ni(II) chelates of substituted chalcones. E-Journal of Chemistry, 1, 105-109. doi:10.1155/2004/385034
[25]	Jellinek, H.H.G. (1978) Aspects of degradation and stabilization of polymers. Elsevier Scientific Publishing Company, New York.
[26]	Singh, B.K., Kumari, P., Prakash, A. and Adhikari, D. (2009) Thermal decomposition kinetics of peanut shell. Nature and Science, 7, 73-78.
[27]	Horowitz, H.H. and Metzger G. (1963) A new analysis of thermogravimetric traces. Analytical Chemistry, 35, 1464- 1468. doi:10.1021/ac60203a013
[28]	Anslyn, E.V. and Dougherty, D.A. (2006) Modern Physical organic chemistry. Edwards Brothers, Inc., Violet Hill.
[29]	Urbach, F. (1953) The long-wavelength edge of photo- graphic sensitivity and of the electronic absorption of solids. Journal of Physical Reviews, 92, 1324. doi:10.1103/PhysRev.92.1324
[30]	Ilyas, M., Zulfequar, M. and Husain, M. (2000) Optical properties of a-(Se70Te30)100–x (Se98 Bi2)x thin films. Journal of Modern Optics, 47, 663.
[31]	Mohamed, S.H., Ahmed, A.M., Diab, A.K. and Wakkad, M.M. (1999) Structural and optical properties of Ge-As- Te thin films. The European Physical Applied Journal, 8, 215-224.
[32]	Soldera, A. and Monterrat, E. (2002) Mid-infrared optical properties of a polymer film: Comparison between classical molecular simulations, spectrometry, and ellipsometry techniques. Polymer, 43, 6027-6035. doi:10.1016/S0032-3861(02)00467-6
[33]	Rajesh, K.R. and Menon, C.S. (2002) Estimation of the refractive index and dielectric constants of magnesium phthalocyanine thin films from its optical studies. Materials Letters, 53, 329-332. doi:10.1016/S0167-577X(01)00502-X
[34]	Wemple, S.H. and DiDmenico, W. (1971) Behavior of the electronic dielectric constant in covalent and ionic materials. Physical Review B, 3, 1338-1351. doi:10.1103/PhysRevB.3.1338
[35]	Dixon, J.R. and Riedl, H.R. (1965) Optical dispersion of lead sulfide in the infrared. Journal of Physical Review A, 140, 1283-1291. doi:10.1103/PhysRev.140.A1283
[36]	Sokkar, T.Z.N., El-Farahary, K.A. and El-Bakary M.A. (2003) Determination of optical properties, dispersion, and structural parameters of poly(ethylene terephthalate) fibers using automatic variable wavelength interferometry technique. Journal of Applied Polymer Science, 89, 1737. doi:10.1002/app.12189
[37]	Abul-Hail, R.Ch. (2010) Optical absorption of polycar- bonate (Makrofol E) as means of gamma-ray dosimetry, Journal of Basrah Researches (Sciences), 36, 26.