Microwave-Assisted Synthesis and Characterization of Poly(itaconic acid) Grafted Gellan Gum

Abstract

Poly(itaconic acid) was grafted on GG in aqueous medium under microwave irradiation using a catalytic amount of BPO. Grafted copolymers (GG-g-PIA) were characterized by FT-IR, TGA, and SEM techniques. The influence of microwave power, exposure time, and composition of the reaction mixture on extent of grafting was studied. Conditions for obtaining the highest extent of grafting were optimized. The rate of grafting was determined from weight measurements. The overall activation energy for grafting is found to be to be 28.3 kJ/mol, indicating the possibility of occurrence of the grafting process with absorption of low thermal energy.

Thermal stability and transition temperatures of monovalent salts of high‐acyl gellan gels

“…The need for polysaccharides with specific characteristics has motivated new ways to modify their original structure. Recently, chemical synthesis has been used to modify the structure of LAG (Coutinho et al ., ; Novac et al ., ; Karthika & Vishalakshi, ), but similar modifications on HAG have not been reported. In a previous investigation (Murillo‐Martínez & Tecante, ), a method to obtain a highly purified NaHAG and its characterisation and transition temperatures without addition of external counterion was reported.…”

Optimization of synthesis condition for carboxymethyl cellulose‐based hydrogel from rice straw by microwave‐assisted method and its application in heavy metal ions removal

“…At excess monomer concentration, the primary radicals attacked the monomer instead of reacting with the CMC backbone. This initiated a homopolymerization reaction to form high ungrafted homopolymer, which led to increase in the viscosity of reaction medium, making it more difficult for the monomer to diffuse and react with the active sites on the CMC backbone, causing lower grafted copolymer hydrogel yield …”

“…The increase in gel content with exposure time could be explained on the basis of increased interactions between initiator, crosslinker, monomer, and polymer backbone under microwave irradiation, resulting in generation of more free radical sites on the CMC backbone as well as AMPS chain and MBA crosslinker . However, the decrease in gel content with prolonged exposure time to 25 min could be attributed to dominance of homopolymerization over graft copolymerization and decomposition of the grafted copolymer . The decreasing gel content was due to excess AMPS monomer and MBA crosslinker at beyond optimum microwave exposure time.…”

“…This initiated a homopolymerization reaction to form high ungrafted homopolymer, which led to increase in the viscosity of reaction medium, making it more difficult for the monomer to diffuse and react with the active sites on the CMC backbone, causing lower grafted copolymer hydrogel yield. 13,[20][21][22] Considering the effect of MBA dose, it was found that an increase of MBA dose up to 0.7 g led to an increase of gel content. MBA plays the important role of crosslinker that has to be present in the polymer to prevent dissolution of the hydrophilic polymer chains in an aqueous environment.…”

“…20 However, the decrease in gel content with prolonged exposure time to 25 min could be attributed to dominance of homopolymerization over graft copolymerization and decomposition of the grafted copolymer. [20][21][22] The decreasing gel content was due to excess AMPS monomer and MBA crosslinker at beyond optimum microwave exposure time.…”