Grafting vinyl monomers onto wool fibers,IX. Graft copolymerization of methyl methacrylate onto wool using peroxydiphosphate-cysteine redox system

The graft copolymerization of methyl methacrylate onto wool was studied at 50°C using peroxydiphosphate-cysteine redox system as initiator. The rate of grafting was determined by varying monomer, initiator, cysteine, acid and temperature. The grafting is considerably influenced by chemical modification prior to grafting. A suitable kinetic path has been pictured and a rate expression has been derived.     

Grafting vinyl monomers onto wool fibers. I. Graft copolymerization of methyl methacrylate onto wool using V5+–thiourea redox system

The graft copolymerization of methyl methacrylate in wool fibers was investigated in aqueous solution using V⁵⁺—thiourea redox system. The rate of grafting was determined by varying monomer, thiourea, acidity of the medium, temperature, nature of wool, different acrylic monomers, and reaction medium. The graft yield increases significantly by increasing reaction time in the initial stages of the reaction but it does slow down on prolonging the duration of grafting. The effect of increasing monomer concentration brings about a significant enhancement in the graft yield. The graft yield increases with increasing thiourea concentration, but beyond 0.0075M, the percentage graft yield decreases. The graft yields are considerably influenced by chemical modification prior to grafting. Wool reduced with thioglycolic acid is more susceptible to grafting than untreated wool; the opposite effect is noted in the case of trinitrophenylated and esterified wools. A suitable kinetic scheme has been proposed and the rate equation has been evaluated.     

Grafting vinyl monomers onto silk fibers. VIII. Graft copolymerization of methyl methacrylate onto silk using tetravalent manganese–oxalic acid redox system

The graft copolymerization of methyl methacrylate onto silk fibers was investigated in aqueous solution using the Mn(IV)–oxalic acid redox system. The copolymerization reaction was carried out under a variety of conditions such as different monomer, initiator, oxalic acid, acid concentrations, and temperatures. The graft yield increases with increasing initiator concentration up to 5 × 10^?2M, and with further increase of the initiator concentration it decreases. The graft yield also increases with increasing sulfuric acid concentration up to 15 × 10^?2M, and decreases thereafter. The rate of grafting also increases with increase in oxalic acid concentration up to 1.5 × 10^?2M and 84.592 × 10^?2M, respectively, and thereafter the rate of grafting shows down. The effect of temperature, solvents, and salts on graft yield has also been investigated and a plausible rate expression has been derived.     

Grafting vinyl monomers onto silk fibers IV. Graft copolymerization of methyl methacrylate onto silk using bromate-thiourea redox system

The use of a bromate-thiourea redox system to initiate graft copolymerization of methyl methacrylate onto silk has been investigated. The rate of grafting has been determined by varying the concentration of bromate ion, monomer, thiourea, the temperature and the solvent. The graft yield increases with increasing the bromate ion concentration up to 20 mmo1/1. With further increase of oxidant the graft yield decreases. The percentage of grafting increases with increase of hydrochloric acid up to 40 mmo1/1. Thereafter it decreases. The effect of increasing thiourea concentration up to 15 mmo1/1. is to bring about an increase in the graft yield. Above this concentration grafting decreases sharply. The rate of grafting increases with increase of temperature. The use of various water soluble solvents effects the percentage of grafting considerably. The alkali solubility of the grafted fiber has been investigated.     

Grafting vinyl monomers onto wool fibers. V. Graft copolymerization of methyl methacrylate onto wool using peroxydiphosphate as initiator

Graft copolymerization of methyl methacrylate onto wool was investigated in aqueous solution using potassium peroxydiphosphate as initiator. The rate of grafting was determined by varying monomer, peroxydiphosphate ion, temperature, solvent, and nature of wool. The graft yield increases with increase in monomer concentration. The graft yield increases significantly by increasing peroxydiphosphate ion up to 80 × 10^?4mole/l.; with further increase of peroxydiphosphate ion the graft yield decreases. The rate of grafting increases with increase in temperature. The effect of acid-and water-soluble solvents on the rate of grafting was investigated and a suitable rate expression has been derived.     

Grafting vinyl monomers onto wool fibers: Graft copolymerization of methyl methacrylate onto wool fibers using vanadyl acetyl acetonate complex

The graft copolymerization of methyl methacrylate (MMA) onto native and reduced Indian Chokla wool fibers was studied in aqueous solution using the acetylacetonate oxovanadium (IV) complex. The rate of grafting was investigated by varying the concentration of the monomer and the complex, acidity of the medium, and the solvent composition of the reaction medium. The graft yield increases with increasing concentration of the initiator up to 8.75 × 10^?5 mol/L, of the monomer up to 0.5634 mol/L, and thereafter it decreases. MMA was found to be the most active monomer when compared to other vinyl monomers. Grafting increases with increasing concentration of HClO₄ and with increasing temperature. Reduced and oxidized wools were found to be better substrates than untreated, esterified, crosslinked, and trinitrophenylated wools. The extent of grafting was mostly dependent upon the concentration of ? SH groups in case of reduced wool. A suitable reaction scheme has been proposed and the activation energy was calculated from Arrhenius plot.     

Grafting vinyl monomers onto silk fibers. X. Graft copolymerization of methyl methacrylate onto silk using hydrogen peroxide–thiourea redox system

The graft copolymerization of methyl methacrylate onto silk fibers initiated by a hydrogen peroxide–thiourea redox system was investigated under various conditions. The effects of monomer, initiator, temperature, acidity of the medium, and solvent on the rate of grafting were studied. The graft yield increases with the increase of monomer and initiator concentration. The graft yield also increases with the increase of acid concentration upto 22.50 × 10^?2M and thereafter it decreases. The effect of some inorganic salts on the rate of grafting has also been investigated, and a suitable mechanism has been suggested.     

Grafting vinyl monomers onto wool fibers IV. Graft copolymerization of methyl methacrylate onto wool using peroxydisulfate catalysed by silver ions

Graft copolymerization of methyl methacrylate onto wool was investigated in aqueous solution using peroxydisulfate catalysed by silver ions. The rate of grafting was determined by varying the concentration of monomer, peroxydisulfate ion, thiourea, the temperature and the solvent. The graft yield increased with increasing monomer concentration, peroxydisulfate concentration, thiourea concentration, and temperature in all cases to a certain value, beyond of which a decrease in graft yield was observed. The effect of certain inorganic salts and water soluble solvents on the rate of grafting was investigated. The alkali solubility of the grafted fiber was studied.     

Grafting vinyl monomers onto polyester fibers. III. Graft copolymerization of methyl methacrylate onto poly(ethylene terephthalate) using potassium permanganate–oxalic acid redox system

The use of the KMnO₄—oxalic acid redox system to initiate graft copolymerization of methyl methacrylate (MMA) onto poly(ethylene terephthalate) (PET) fiber has been investigated. The rate of grafting was determined by varying the concentrations of monomer, KMnO₄, oxalic acid, acidity of the medium, and temperature. The graft yield increases steadily with increasing KMnO₄ concentration. The graft yield is also influenced with concentration. The graft yield is also influenced with temperature. The effect of certain solvents on the rate of grafting has been investigated, and a suitable reaction mechanism has been proposed.     

Grafting vinyl monomers onto polyester fibers. VI. Graft copolymerization of methyl methacrylate onto PET fibers using tetravalent cerium as initiator

The graft copolymerization of methyl methacrylate onto polyester fibers (PET) was investigated using tetravalent cerium as the initiator. The rate of grafting was found to increase progressively with the initiator and monomer concentrations up to 2.5 × 10^?2M and 70.41 × 10^?2M, respectively. The reaction was found to be catalysed by acid up to 15.0 × 10^?2M. The graft yield increased by increasing temperature. The effect of addition of some solvents and thiourea on the rate of grafting was also investigated. A suitable kinetic scheme has been pictured, and rate equations have been derived.     

Grafting vinyl monomers onto silk fibers,VII. Graft copolymerization of methyl methacrylate onto silk using peroxydiphosphate as initiator

Graft copolymerization of methyl methacrylate onto silk was investigated in aqueous solution using potassium peroxydiphosphate as initiator. The rate of grafting was determined by varying monomer, peroxydiphosphate ion, temperature, and solvent. The graft yield increased with increasing peroxydiphosphate ion upto 8 × 10^?3 mol/1 and with further increase of peroxydiphosphate ion the graft yield decreased. The graft yield increased with increasing monomer concentration upto 9 wt.-% and with further increase of monomer the graft yield decreased. The rate of grafting increased with the increase of temperature. The effect of acid and water soluble solvents and salts on graft yield was investigated and a suitable rate expression was derived.     

Grafting vinyl monomers onto silk fibers III. Graft copolymerization of methyl methacrylate onto silk using tetravalent cerium as initiator

The use of tetravalent ceric ions to initiate graft-copolymerization of methyl methacrylate onto silk has been investigated. The rate of grafting has been determined by varying monomer, cerium (IV), temperature, and nature of silk. The graft yield increases with increasing monomer concentration up to 0.65 mol/l and with further increase of monomer, the graft yield decreases. The percentage of grafting increases with increasing ceric ion concentration up to 0.03 mol/l and thereafter it decreases. The rate of reaction is temperature dependent, with increasing temperature, the graft yield increases. The grafting is considerably influenced by chemical modification prior to grafting. The effect of different species of ceric ion and CuSO₄ on the rate of grafting has also been investigated.     

Grafting vinyl monomers onto silk fibers. II. Graft copolymerization of methyl methacrylate onto silk by hexavalent chromium ion

The feasibility of chromium(VI) to induce graft polymerization of methyl methacrylate onto silk was investigated. The rate of grafting was determined by varying monomer concentration, chromium(VI) concentration, temperature, acidity of the medium, nature of the silk, reaction medium, and redox system. The graft yield increased with increasing monomer concentration up to 0.65M, and with further increase of monomer the graft yield decreased. The graft yield increased with increasing chromium(VI) concentration. The grafting is considerably influenced by chemical modification of silk prior to grafting. The graft yield is influenced by thiourea concentration, decreasing with increasing thiourea concentration. The effect of certain inorganic salts and anionic surfactants on the rate of grafting was investigated.     

Grafting vinyl monomers onto cellulose. I. Graft copolymerization of methyl methacrylate onto cellulose using quinquevalent vanadium ion

Graft copolymerization of methyl methacrylate on cellulosic materials with the use of quinquevalent vanadium as an initiator was studied. Increase of V⁵⁺ion concentration up to 0.0025 mole/liter increases graft yield, and with further increase of the initiator the graft yield decreases. The graft yield increases with increase of monomer concentration. The increase of acid concentration is accompanied by decrease of graft yield. A measurable increase in graft yield was observed with increase in temperature from 65 to 75°C. The graft yield is medium and substrate dependent. A suitable kinetic scheme has been pictured and a rate equation has been derived.