Biodegradation behavior of the prepared polyacrylic acid-graft-pectin hydrogel via ionizing radiation

Abstract Direct gamma irradiation was used for the synthesis of hydrogels of polysaccharides such as pectin with acrylic acid monomer (AAc) in order to create the PAAc-g-pectin hydrogel. The optimal ratio of polymer to monomer in pectin (PAAc) is 3:2 (v/v). A dose of 20 kGy is the ideal for radiation exposure. The study investigated the swelling behaviours of the PAAc-g-pectin hydrogel at different pH values and in neutral distilled water. The highest percentage of swelling was observed at pH 10. Atomic force microscopy (AFM), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) were used to examine the prepared hydrogel structure and confirm its morphology. Several soil samples were taken from Upper Egypt (TOSHKA), from Delta zone (Dakhalia governorate), and from East Cairo in order to study the effect of soil pH on the biodegradation process. The rate of biodegradability of the prepared hydrogel based on natural polymer (Pectin) in different soil pH was measured by the weight loss methodology and compared with the biodegradation rate of the neat PAAc. The biodegradation percent of the PAAc-g-pectin hydrogel in soil burial over 16 weeks exhibits (67.92%) weight loss % at soil pH (9.4) and (48.86%) weight loss % at soil pH (7.6) compared with the synthetic PAAc which exhibits (29.48%) weight loss % at soil pH (9.4) and (25.2%) weight loss % at soil pH (7.6). Graphical abstract