Grafting of methyl methacrylate onto sodium alginate initiated by potassium ditelluratoargentate(III)

Abstract

Sodium alginate (SA) was graft-copolymerized with methyl methacrylate in an alkali aqueous solution with potassium ditelluratoargentate(III) (DTA) as the initiator. Graft copolymers with both a high grafting efficiency (Ͼ90%) and a high percentage of grafting were obtained, which indicated that the DTA-SA redox pair was an efficient initiator for this grafting. The grafting parameters, including total conversion, grafting efficiency, and percentage grafting, were evaluated comparatively. The dependence of these parameters on temperature and time, monomer concentration, initiator concentration, and SA backbone concentration was also investigated. The overall activation energy of this grafting was calculated as 37.50 kJ/mol. Proof of grafting was obtained from gravimetric analysis and IR spectra. A tentative mechanism involving a two-step, single-electrontransfer process of DTA is proposed to explain the generation of radicals and the initiation of grafting. Some basic properties of the grafted copolymer were studied by instrumental analyses, including thermogravimetry, X-ray diffraction, and scanning electron microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1688 -1694, 2005

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

“…In addition, the decrease in the monomer‐to‐backbone ratio also accounted for the observed decrease in % G . Similar observations have also been reported earlier …”

Graft copolymerization of N‐vinyl‐2‐pyrrolidone onto sodium carboxymethylcellulose with azobisisobutyronitrile as the initiator

“…Similar results were found for the graft copolymerization of acrylamide onto cellulose with ceric ammonium nitrate. 17 Liu et al 18 studied the grafting of methyl methacrylate onto another polysaccharide sodium alginate with potassium ditelluratoargentate(III). They reported the same trend for the effect of the reaction time on the grafting parameters.…”

“…Similar results have been obtained by many workers who have studied graft copolymerization. [18][19][20][21] Zhang and Tan 19 studied the graft copolymerization of 2-(dimethylamino)ethyl methacrylate onto carboxymethylated cellulose and reported that the grafting parameters increased with an increase in the temperature up to 358C and then decreased up to 608C.…”

“…A decrease in the grafting parameters were observed with a further increase in the initiator concentration, and this was consistent with the results of our previous studies 16,25 and others' studies. 18,22,23,26 Gupta and Sahoo 26 studied the Co(III) acetylacetonate complex initiated grafting of N-VP on cellulose in aqueous media and observed that the yield percentage increased up to 15 Â 10 À5 M initiator and then decreased with an increase in the initiator concentration.…”

Modification of alginate through the grafting of 2-acrylamidoglycolic acid and study of physicochemical properties in terms of swelling capacity, metal ion sorption, flocculation and biodegradability

“…Grafting of vinyl monomers onto alginate and other natural polysaccharides through free radical polymerization has attracted the interests of many researchers and scientists in the last two decades (Liu, Yang, Li, & Shi, 2005;Osemeahon, Barminas, Aliyu, & Nkafamiya, 2008;Sirlatha & Rao, 2007). This technique enables the production of new hybrid polymer materials with desired properties (Fakhru'L-Razi et al, 2001;Patel, Patel, & Trivedi, 1999;Pourjavadi, Hosseinzadeh, & Mazidi, 2005).…”