Ceric‐initiated free radical graft copolymerization of acrylonitrile onto kappa carrageenan

Abstract

The polysaccharide, kappa carrageenan (kC), was modified using ceric-initiated graft copolymerization of acrylonitrile (AN) under inert atmosphere in a homogeneous aqueous medium. Grafting was confirmed using FTIR spectroscopy, solubility test, elemental analysis, acid hydrolysis, and thermogravimetric analysis (TGA). kC-graft-poly(AN) products had a higher thermal stability than kC as revealed by TGA analysis. The polyacrylonitrile branches were isolated by acidic degradation of the carrageenan main chains and characterized by size exclusion chromatography (SEC). Residual monomers were not found by HPLC in graft copolymers stored even for longer periods. The effect of various factors affecting on grafting, i.e., concentration of the initiator, monomer, and polysaccharide as well as the reaction time and temperature were studied by conventional methods to achieve the optimum grafting parameters. The graft copolymerization reactions were kinetically investigated using semiempirical expressions and a suitable rate expression has been derived. According to the empirical rates of the polymerization and the graft copolymerization of AN onto kC backbone, the overall activation energy of the graft copolymerization reaction was estimated to be 20.96 kJ/mol.

Photo‐induced graft copolymerization of acrylonitrile onto sodium salt of partially carboxymethylated guar gum

“…Therefore, the homopolymerization becomes the preferred process and decrease in %G and %GE is observed. Similar results are also reported in the literature …”

“…Similar results are also reported in the literature. 7,21,[29][30][31][32][33][34][35][36] Effect of Reaction Time Grafting reaction was also studied by varying the time period from 0.5 to 10 h and the results are depicted in Figure 6. It can be seen from this figure that the value of %G increased with increase in reaction time up to 6 h and thereafter it remains unchanged with further increase in time.…”

Carrageenans from nuclear phases of subantartic Mazzaella laminarioides (Gigartinales, Rhodophyta) and graft copolymerization of alkali-modified carrageenan with acrylamide

“…By conventional method The copolymerization of polysaccharide with acrylamide using the conventional method with cerium ammonium nitrate as a free radical initiator was performed by a modification of the method reported by Hosseinzadeh (2009). Briefly, 0.120 g of polysaccharide was stirred in 100 mL distilled water at 60°C under nitrogen atmosphere.…”

“…Recently, studies on the application of carrageenans in drug delivery systems have gained much interest (Nanaki et al 2010;Rana et al 2011;Li et al 2013Li et al , 2014. On the other hand, copolymerization of carrageenans with vinyl monomers produces graft copolymers with new properties and applications Meena et al 2006;Pourjavadi et al 2008;Hosseinzadeh 2009;Mishra et al 2010;Sand et al 2012;Yadav et al 2012;Verma et al 2014).…”

Magnetic and pH‐responsive starch‐g­‐poly(acrylic acid‐co­acrylamide)/graphene oxide superabsorbent nanocomposites: One‐pot synthesis, characterization, and swelling behavior

“…However, no investigations have been reported on a natural SANC composed of GO/MIONs. So, following on continuous research on modification of biopolymers , we attempted to synthesize of a novel biopolymer‐based SANCs through graft copolymerization of poly(acrylic acid‐ co ‐acrylamide) onto starch backbones. The synthesized SANCs via this facile and efficient preparation strategy can be useful for various potential applications such as carriers for controlled drug delivery and agricultural applications.…”