Grafting of Methyl Acrylate onto Cellulose by Ceric Ion

Graczyk, Tomasz; Hornof, V.

doi:10.1080/10601328808055091

Cited by 16 publications

(5 citation statements)

References 20 publications

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“…There are contradictory reports regarding the ceric ions initiated grafting of vinyl monomers. Some studies , highlight that ceric ions promote homopolymer formation through facile reaction of ceric ions with monomers, but others considered it as a potential initiator to obtain optimum grafting under mild conditions. The formation of homopolymers during ceric ions initiated graft copolymerization has been attributed to the chain transfer from the growing graft copolymers to the monomer .…”

Section: Resultsmentioning

confidence: 99%

Graft Copolymerization of Acrylonitrile and Ethyl Methacrylate Comonomers on Cellulose Using Ceric Ions

Gupta

Sahoo

2001

Biomacromolecules

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The graft copolymerization of acrylonitrile and ethyl methacrylate from their binary mixtures onto cellulose has been carried out in the presence of Ce(IV) ions in acidic media at 30 +/- 0.1 degrees C. The graft copolymerization has shown an increasing trend on increasing the feed molarity of the comonomers and on increasing the reaction time. The analysis of grafted cellulose prepared with different feed compositions (f(AN)) has clearly indicated the existence of the synergistic effect of ethyl methacrylate on acrylonitrile which normally shows poor affinity for grafting on cellulose while used individually. The elemental analysis and IR data were used to determine the composition of grafted copolymers and reactivity ratios (r(1), r(2)) of the monomers using the Mayo and Lewis method. The reactivity ratios for acrylontrile and ethyl methacrylate have been found to be 0.68 and 1.15, respectively, which supported the alternate arrangement of the monomer blocks of individual monomers in the grafted chains. The rate of grafting has shown a square dependence on the concentration of the comonomers within the studied range of feed molarity from 0.5 to 2.5 mol dm(-3). The grafting data were used to calculate the number of grafted chains (N(g)), frequency of grafting (G(F)) per molecule of the cellulose and efficiency of grafting (G(E)). The variation in these parameters as a function of feed molarity, feed composition, and ceric ion concentration has been determined. The rate of ceric ion disappearance as a function of feed molarity and reaction time has provided strong support to consider the participation of ceric ions in the formation of free radicals at the backbone of the cellulose. On the basis of the experimental observations, reaction steps for grafting of monomers on cellulose have been proposed.

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Section: Resultsmentioning

confidence: 99%

Graft Copolymerization of Acrylonitrile and Ethyl Methacrylate Comonomers on Cellulose Using Ceric Ions

Gupta

Sahoo

2001

Biomacromolecules

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“…The isolated PEMA and PAN grafts were purified by solution in benzene and dimethylformamide respectively and precipitation with methanol and airdried. The molecular weights of the polymers were determined from viscosity measurement using the following relationships log(ŋ) = log 4.75 x 10 -4 + 0.50Mv ( 2) log(ŋ) = log 3.35 x 10 -4 + 0.72Mv (3) for PEMA in isopropanol at 30 0 C and PAN in dimethylformamide at 30 0 C respectively. The frequency of grafting (FG), defined as the number of polymer grafts per 10 4 anhydroglucose units (AGU), was calculated using the relationships Fg = (weight of grafted polymer)(mw of AGU)*104 mw of grafted polymer … ( 4)…”

Section: Acrylonitrilementioning

confidence: 99%

“…Ceric ion has been used to initiate graft copolymerisation of many monomers on various substrates [1][2][3][4][5][6][7] . Grafting is generally considered to result from propagation by radicals generated on the backbone polymer.…”

Section: Introductionmentioning

confidence: 99%

Graft Copolymerization of Acrylonitrile and Ethyl Methacrylate on Dextrin

Okieimen¹,

Amaye²,

Jideonwo³

2007

Nigerian Journal of Chemical Research

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Graft copolymers of Acrylonitrile and ethyl methcrylate on dextrin were prepared by the use of ceric ion initiator in aqueous medium at 29 0 C. The molecular weight of grafted poly(ethyl methacrylate) chains were higher than for polyacrylonitrile grafts; but the latter were more frequently grafted on the backbone polymer. The dependence of the molecular weight of the grafted chains on ceric ion concentration suggests that interaction of growing graft polymer chains with ceric ion is important in the termination process of graft copolymerisation. Graft copolymeriation of ethyl methacrylate onto dextrin in the presence of various amounts of acrylonitrile was studied. The compositions of the copolymer samples, calculated from their nitrogen content, showed that in the presence of ethyl acrylate, relatively small amounts of acrylonitrile monomer was grafted onto dextrin.

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“…Polymer chains can be attached to a preexisting polymer backbone of a similar or completely different composition to form what is termed a graft copolymer. Acrylic branches can be added to either synthetic (119,120) or natural (121)(122)(123)(124) backbones. Attachment of graft polymer branches to preformed backbones is accomplished by chemical (125)(126)(127), photochemical (128,129), radiation (130), and mechanical (131) means.…”

Section: Graft Copolymerizationmentioning

confidence: 99%