Study on radiation‐induced grafting of hydrophilic monomers onto chitosan

Abstract

The graft polymerization of 2-Hydroxyethyl acrylate, 2-Hydroxyethyl methacrylate, and N-vinylpyrrolidone onto chitosan in aqueous solution initiated by g-ray irradiation was carried out. The effect of various conditions such as the absorbed dose, concentration of monomer, and solvent on grafting was investigated. The grafting yield increased with the increase in absorbed dose. The degree of grafting increased with increase in the radiation dose. The obtained graft copolymers showed the solubility in water in wide pH interval. The interactions between grafted chitosan copolymers with sodium dodecyl sulfate (SDS) were studied in an aqueous solution. It was found that there is a narrow molar ratio of SDS/cation ($ 0.40-0.70) depending on different grafted copolymers, at which the turbidity of SDS-grafted chitosan complex has a maximum due to the formation of water insoluble interpolymer aggregates via the SDS attached on the polymer chain. The turbidity falls sharply with the further addition of excessive SDS, which forms micelle in the solution and causes the de-aggregation of the interpolymer aggregates and also because of the precipitation of complexes and returns to the original level. The morphologic properties of thin films of SDS-grafted chitosan complex were investigated. It was observed that upon heating the insoluble complex of SDS and grafted chitosan in water, superstructures were formed.

Functionalization of chitosan with carboxylic acids and derivatives of them: Synthesis issues and prospects of practical use: A review

“…Besides the abovementioned redox radical initiators, the graft polymerization under γ-irradiation of 60 Co was also possible. For example, the chitosan modification via the graft copolymerization of 2-hydroxyethyl(meth)acrylates and N-vinylpyrrolidone under γ-irradiation was carried out in acidified water and in sealed ampoules under inert atmosphere [148]. It was proven that the polymerization degree of the grafted residues was directly proportional to the radiation dose, and insoluble products formed only in extreme cases.…”

Antioxidant–polysaccharide conjugates for food application by eco-friendly grafting procedure

“…The conventional grafting polymerization technique requires, indeed, the introduction of chemical groups to impart new characteristics, to the modified polymers, for different applications (Dergunov et al, 2008;Joung, Choi, Bae, & Park, 2008;Shin, Lee, & Park, 2008). It is well known that for some specific polymeric products, especially medical equipment and food packaging, sterilization via radiation is needed with a potential risk of degradation, i.e., chain scission and/or crosslinking, resulting in discolouration, cracking of the surface, stiffening, and loss of mechanical properties (Jahan & McKinny, 1999).…”

Synthesis and properties of a water soluble graft (chitosan-g-2-acrylamidoglycolic acid) copolymer

“…Percent swelling (P s ) = Swelling ratio (S r ) × 100 (2) where W 1 and W 2 are the mass of sample (g) before and after swelling, respectively.…”

“…The synthesis of graft copolymers has become a rapid expanding field in the area of polymer science [1][2][3][4]. Since the last two decades much attention has been paid by several scientists and researchers to synthesize a variety of hybrid materials based on graft copolymer using different approaches [5][6][7][8][9][10][11].…”