Mohamad S; Nahida J.Hameed Al-Mashhadan
Abstract
The samples were cast as thin film from homopolymer (PMMA) before and after doping with methyl orange at different concentration. The samples were exposed to UV-radiation for exposure ...
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The samples were cast as thin film from homopolymer (PMMA) before and after doping with methyl orange at different concentration. The samples were exposed to UV-radiation for exposure time within (10-50hr) range. These polymer systems were evaluated spectrophotometrically for using the UV-detector. The absorption spectra of UV-irradiated samples showed radiation induced absorption changes in the wavelength range, which depends on the polymer type and polymer composites. The increment depends dopant concentration, especially in ultra violet region in exposed PMMA doped with methyl orange at 6.7×10-2wt/wt concentration. Decreasing in absorption was found for the cases in which, photo degradation caused surface damage, i.e. crazes or cracks formation, especially at ultraviolet region. Calibration curves were drawn at peaks, selected wavelength in the absorption spectra. The linear regions from the calibration curves were selected, and dosimeter range was determined from the UV-irradiation sample response. It was found that PMMA doped with methyl orange at 6.7×10 -2wt/wt concentration can be use the UV-detector within range (10-40hr) at the wavelength of (300nm) for its linear response at this range of irradiation. Morphological investigations for the surface damages caused by thermal and photo degradation are detected by optical microscope. It is found that the photo degradation could easily lead to some mechanical surface degradation i. e (crazes and cracks) formation.
