Molecular weight studies of the γ‐irradiation degradation of poly(methyl methacrylate) doped with poly(p‐sulfanilamide)

Abstract

The protection of some poly(methyl methacrylate) (PMMA) samples against c rays was investigated in the absence and presence of poly(p-sulfanilamide). Pure PMMA (without additives) and PMMA-poly(p-sulfanilamide) blend samples were irradiated with c rays for different exposure doses (5,15,25,35, 50, 75, and 100 kGy). The viscosity-average molecular weights were determined and thin-layer chromatography measurements were carried out after each irradiation dose. The maximum protection against c rays was found when 1% poly(p-sulfanilamide) was used. The radiation chemical yield for main scission (G s ) was calculated and had lower values in the case of 1% poly(p-sulfanilamide). The energy absorption per scission was maximum for 1% poly(p-sulfanilamide), and this confirmed the obtained G s data. From thin-layer chromatography studies, it was observed that both the retention factor (R f ) values and polydispersity of the PMMA samples increased with an increasing exposure dose. The effect of c irradiation on PMMA films doped with 1% poly(p-sulfanilamide) was investigated with UV spectroscopy after the extraction of the additives. A change in the intensity of the absorption bands with an increasing irradiation dose was recorded. It is suggested that PMMA films doped with this type of polymer can be used as dosimeters.

Patterning of Wrinkled Polymer Surfaces by Single-Step Electron Irradiation

“…Height initially increased when the electron fluence also rose due to the elastic property of a polymer that causes the wrinkle height to increase with increasing applied compressive stress. However, the molecular weight of irradiated PMMA decreases exponentially with increasing electron irradiation fluence, , signifying that the scission rate of PMMA becomes insignificantly small past a certain dose. Figure strongly supports this fact as it shows that the glass-transition temperature of PMMA and the received dose also have a closely inversely exponential relationship.…”

Well-Controlled Emulsion Polymerization of Methyl Methacrylate Using (Hg,Cd)-Diphenylcarbazone Catalysts: An attempt to Create Hg-free, Nontoxic, γ-Radiation and thermal Stable Films

“…As revealed, pure PMMA showed a 68.2% heterotacticity which indicated that it is nearly amorphous [26]. In the presence of cadmium and mercury complexes, the tacticity of all samples was signi cantly improved as shown in Table 2, reducing in turn the amorphous region that is the most susceptible for all physical and chemical interactions and degradation compared to the crystalline region [45]. The overall results clearly indicate the direct outcome of the carbazone complexes role as catalyst and regulator during the emulsion polymerization of MMA which enrich the prepared polymers with an explicated effectiveness against radiation.…”