Photograft copolymerization of methyl methacrylate on viscose fiber using titanium(III) chloride–potassium persulfate redox initiator in a limited aqueous system

The graft copolymerization of methyl methacrylate (MMA) onto viscose fibers were studied under photoactive conditions with visible light using titanium(III) chloride—potassium persulfate as redox initiator in a limited aqueous system. Polymerization carried out in the dark at 40 ± 1°C produced little graft copolymer whereas that in the presence of light at 40 ± 1°C produced significant grafting. Percent grafting, percent total conversion, and grafting efficiency (%) were studied by varying time, initiator concentration, monomer concentration, solvent composition, and pH of the medium. High percent grafting (～ 200%), high grafting efficiency (～ 98%), and percent total conversion (～ 47%) were obtained with little homopolymer formation. A suitable mechanism for grafting has been discussed and also the characterization of the grafted fibers were studied by Fourier transform infrared (FTIR) spectroscopy, thermogravimetry and scanning electron microscopy (SEM). © 1992 John Wiley & Sons, Inc.     

Graft copolymerization of methyl methacrylate on silk fiber using mohr's salt—potassium persulfate as redox initiator under visible light in a limited aqueous medium

Graft copolymerization of methylmethacrylate onto mulberry silk fibers was studied under photoactive conditions with visible light using the Mohr's salt-potassium persulfate as the redox initiator in a limited aqueous medium. Polymerization in the presence of light at 40±1°C was found to be more pronounced than that in the dark at 40±1°C. Percent grafting, percent total conversion, and grafting efficiency under different sets of conditions were studied, and the mechanisms of polymerization and graft copolymer formation were discussed. Characterization of the grafted fibers was done by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, and thermogravimetry. © 1996 John Wiley & Sons, Inc.     

Graft copolymerization of methyl methacrylate (MMA) onto silk using potassium peroxydiphosphate–cysteine (PP–Cys) redox system

Poly(methyl methacrylate) has been grafted onto mulberry silk in an aqueous medium by using potassium peroxydiphosphate–cysteine (PP–Cys) redox initiator. Various effects upon grafting such as concentration of cysteine, concentration of peroxydiphosphate, concentration of monomer, concentration of sulfuric acid, and temperature were studied. At a low range of cysteine concentration (6.25 × 10^?4 mol/L), the rate of polymerization R_p (%/s) is proportional to cysteine concentration and the exponent is calculated to be 0.8. The monomer exponent is calculated to be unity up to the concentration of 65.72 × 10^?2 mol/L. From the Arrhenius plot of log R_p vs. 1/T (T = absolute temperature) the overall activation energy is computed to be 15.19 kcal/mol. A suitable kinetic path has been pictured and a rate expression has been derived.     

Graft copolymerization of methyl methacrylate onto jute fiber initiated by cerium(IV)–DMSO redox initiator system

The kinetics of graft copolymerization of methyl methacrylate (MMA) onto chemically modified jute fibers initiated by the Ce(IV)–DMSO redox system was studied in the temperature range of 40–60°C. By studying the effects of the concentration of the monomer, Ce(IV), and DMSO on the rate of grafting, the optimum conditions for grafting were determined. Also, the effect of temperature, time, concentration of the acid, the amount of jute fiber, and some inorganic salts and organic solvents on the rate was investigated. A kinetic scheme was proposed on the basis of the experimental findings. Infrared spectra of chemically modified jute and grafted jute was investigated. More than 120% of grafting could be achieved with the present system. The characterization of MMA-grafted chemically modified jute by TGA and DTA studies was made. The thermal stability of the jute fibers was improved by grafting. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2569–2576, 1998     

Graft copolymerization of methyl methacrylate onto biomedical polyvinyl chloride initiated by Ce(IV)–glucose redox system

Graft copolymerization of methyl methacrylate onto PVC was carried out using Ce(IV)–glucose redox system in aqueous sulfuric acid medium under nitrogen atmosphere. To find out the optimum conditions for grafting, effects of concentrations of metal ion, glucose, monomer, and acid on the percentage of grafting was studied. The graft yield was found to be influenced by reaction time, temperature, and amount of PVC. An appreciably high graft yield could be achieved with the present system. On the basis of the results from the present study, a plausible reaction mechanism has been proposed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2105–2111, 2005     

Grafting vinyl monomers onto silk fibers. XV. Graft copolymerization of methyl methacrylate onto silk using thallium (III) as initiator

The graft copolymerization of methyl methacrylate onto silk initiated by thallium (III) perchlorate was investigated in aqueous medium. The rate of grafting was evaluated varying the concentration of monomer, initiator, and acid, and the temperature. The graft yield was found to increase with increasing the monomer and initiator concentrations. The graft yield was found to decrease with increasing the acid concentration. The effect of inhibitors and various solvents on the graft yield was studied. From the Arrhenius plot the overall activation energy was found to be 4.2 kcal/mol. A suitable kinetic scheme has been proposed, and a rate equation has been derived.     

Graft copolymerization of methyl methacrylate onto starch using a Ce(IV)–glucose initiator system

Graft copolymerization of methyl methacrylate onto starch was carried out in aqueous medium using Ce(IV)–glucose initiator in the temperature range 40–60°C. Effects of concentration of Ce(IV), glucose, H₂SO₄, monomer, and starch on grafting were investigated. Percentages of grafting were evaluated and compared. The overall energy of activation was calculated from the effects of time and temperature of polymerization. The reaction mechanism was also discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 981–990, 2004     

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 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 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.     

(Photo) graft copolymerization of methyl methacrylate (MMA) on polyamine-modified oxycellulose in a limited aqueous system

Graft copolymerization of methyl methacrylate (MMA) on oxycellulose modified with a polyamine [diethylene triamine (DETA)] was studied in a limited aqueous system under photoactivation in visible light using K₂S₂O₈ as the intiator. No polymerization was observed in the dark or in presence of light in 80 min in the case of DETA-treated cellulose; however, ready graft copolymerization resulting in high percent grafting and grafting efficiencies took place in the case of DETA-modified oxycellulose system under photoactivated conditions. DETA-modified oxycellulose prepared from oxycellulose corresponding to low degrees of oxidation (copper nos. 1.5–3.5) produced optimum grafting. The grafting parameters under different sets of conditions were studied and compared, and the mechanism of graft copolymerization was discussed.     

Graft copolymerization of methyl methacrylate (MMA) on hydrazine treated oxycellulose in limited aqueous system

Graft copolymerization of methyl methacrylate (MMA) on oxycellulose modified with hydrazine treatment was studied in a limited aqueous system using K₂S₂O₂ as the initiator. Hydrazine modified oxycellulose prepared from oxycellulose corresponding to low degrees of oxidation (copper nos. 2–6) produced the best grafting effects. Grafting parameters under different sets of conditions were studied and compared and the mechanism of graft copolymerization discussed.     

Preparation and characterization of poly(methyl methacrylate) grafted sago starch using potassium persulfate as redox initiator

In this article, the graft copolymerization of methyl methacrylate (MMA) onto sago starch (AGU) was carried out in aqueous medium using potassium persulfate (PPS) under nitrogen gas atmosphere. The maximum percentage of grafting achieved was 90% under optimized conditions of reaction temperature, monomer, PPS, AGU, and reaction period corresponding to 50°C, 47 mmol, 1.82 mmol, 6.17 × 10^?3 mol L^?1, and 1.5 h, respectively. The grafting of MMA onto sago starch was confirmed by the differences in infrared spectroscopy. The viscosity measurement and the average molecular weight determination were estimated using Huggin's and Mark Houwink's equations, respectively. This material may have application as a biodegradable plastic. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1891–1897, 2004     

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.     

Preparation and properties of chitosan‐graft‐poly(methyl methacrylate) nanoparticles using potassium diperiodatocuprate (III) as an initiator

Graft copolymer nanoparticles prepared from chitosan (CS) and methyl methacrylate (MMA) monomer were synthesized in aqueous solution by using potassium diperiodatocuprate [Cu(III)] as an initiator and characterized in terms of particle size, zeta potential, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, thermal stability, and X‐ray diffraction spectrometry. The results indicated that CS was covalently linked to poly(methyl methacrylate) (PMMA), and the resulting copolymers formed nanoparticles. These nanoparticles [prepared at 35°C, in a weight ratio of MMA/CS of 5 : 1 and with a Cu(III) concentration of 1.5 × 10⁻³ mol/L] were 54–350 nm in size, with a mean hydrodynamic diameter of 183 ± 3 nm and were highly uniform in particle‐size distribution, with a rather spherical shape and an obvious positive charge surface. The effect of reaction conditions such as Cu(III) concentration, reaction temperature, and the weight ratio of MMA/CS on the mean particle size was also investigated. Insulin‐loaded nanoparticles were prepared, and their maximal association efficiency was up to 85.41%. The experiment of release in vitro showed that the nanoparticles gave an initial burst release followed by a slowly sustained one. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Graft copolymerization with a new class of acidic peroxo salts as initiator. V. Grafting of methyl methacrylate onto jute fiber using potassium monopersulfate catalyzed by Fe(II)

Graft copolymerization of methyl methacrylate (MMA) onto jute fibers was studied in an aqueous solution using a new class of acidic peroxo salt, potassium monopersulfate, as initiator, under the catalytic influence of Fe(II) under nitrogen atmosphere. The grafting reaction was influenced by the reaction time, temperature, and concentrations of monomer, initiator, and jute fibers. The grafting reactions have also been studied in the presence of various salts and solvents. The maximum grafting percent (385.4%) has been observed at 35°C for the concentration of monomer (1.4082M), initiator (12.9 × 10^?3M), catalyst (2.5 × 10^?4M), and solvent (acetic acid) composition of (40:60) for a reaction time of 6 h. From the experimental results a suitable mechanism for the graft initiation and termination has been put forth. The graft copolymers have been characterized, and their improved properties such as tensil strength tested.