Plasticization Effect on the Photodegradation of Poly (4-Chlorostyrene) and Poly (4-Bromostyrene) Films

Abstract

The photodegradation of thin films of poly (4-chlorostyrene) and poly (4-bromostyrene) with 265 nm radiation in the presence of oxygen and as a function of irradiation time has been studied mainly using fluorescence, FT-IR, and UV-VIS spectroscopic techniques. The influence of phthalate and terephthalate plasticizers on photo-oxidative degradation was also investigated. Phthalate and terephthalate-plasticizers were found to increase the photodegradation processes in polymeric chains. On the other hand, the intensity of absorption was also found to increase with irradiation time and in the intensity of a new absorption band at longer wavelength. The appearance of new fluorescence bands in the irradiated polymer films can well indicate a possibility of photodegradation of polymer films. In addition, the observed increase in the intensities of the carbonyl and hydroxyl regions of the FT-IR spectra, providing evidence for the photodegradation as well as the photo-oxidation of polymeric chains. The increase in the analyzed ranges wasattributed to the formation of alcohols, aliphatic ketones and to the increase in the number of (C=C) that resulted from hydrogen abstraction during chains-scission.

Study the Influence of UV-Irradiation on the Photo Stability of Pure and Plasticized Poly (4-Vinyl Biphenyl) in Solid Films

“…The same observations were observed in the UV-irradiation of Substituted polystyrene in solid films [19] [44]. Figure 9 shows the FT-IR spectra of non-irradiated and irradiated for (0.0 and 120 min) of blended PVBP with (10% DOT), (10% DET) and (10% DMT) in solid films at irradiation wavelength of 288 nm.…”

Fourier‐transform infrared spectroscopic study of plasticization effects on the photodegradation of poly(fluorostyrene) isomers films

“…The preparation of PFS isomers from their monomers was reported in our previous papers [4][5][6]. The measured M w for the prepared PFS isomers by viscosity measurements gave the following values: o-PFS (M w 5 21,000), m-PFS (M w 5 19,000), and p-PFS (M w 5 16,600).…”

“…The measured M w for the prepared PFS isomers by viscosity measurements gave the following values: o-PFS (M w 5 21,000), m-PFS (M w 5 19,000), and p-PFS (M w 5 16,600). The casting of solid films for these three isomers using spectrograde dichloroethane as solvent was also reported in our previous papers [4][5][6]. Irradiation processes of solid films were exposed to different intervals of irradiation time in air, from (0 to 3 h), using a JASCO spectrofluorometer with a built-in Hydrogen-Xenon lamp (6808-J007A Model ESC-333), and supported with monochromator of holographic grating with 1,800 grooves/mm.…”

“…Polystyrene is one of the most ubiquitous of commercial polymers, because of the huge variety of its applica-tions. Photo-initiated degradation and photo-oxidation of polymeric chains in the presence of air for polystyrene and substituted polystyrene have been reported to typically occur with ultraviolet (UV) exposure over the range of (250-400 nm) [1][2][3][4][5][6] and can be initiated even by ordinary sunlight [7]. Photodegradation is sometimes referred to as light-initiated chain scission crosslinking.…”

“…It has been reported that photodegradation of most of the substituted polystyrene is more easily photodegradable than polystyrene, owing to the weak bonds in substituted polystyrene chromophores. Recently, studies of photodegradation of ring substituted polystyrene have showed that degradation characteristics are sensitive to the nature of substituents, in particular, electron-withdrawing groups (Cl and Br) that tend to reduce the stability of polymeric chains, largely by producing depolymerization radicals [4,16]. On the other hand, fluoro-atom substitution in the phenyl ring in the polymeric structure tends to stabilize the polymer toward irradiation [27].…”