Pentavalent vanadium ion–cellulose thiocarbonate redox-system induced grafting of methyl methacrylate and other vinyl monomers onto cotton fabric

Cellulose thiocarbonate was prepared by reacting cotton cellulose fabric with carbon disulphide in the presence of sodium hydroxide. The treated fabric formed, with pentavalent vanadium ion, an effective redox system capable of initiating grafting of methyl methacrylate (MMA) and other monomers no+o the cotton fabric. The dependence of grafting on vanadium concentration, pH of the polymerization medium, temperature and duration of grafting, nature and concentration of monomer, and solvent/water ratio was studied. The results indicated that increasing the pentavalent vanadium (V^v) concentration up to 60 mmol/L was accompanied by enhancement in the rate of grafting; the latter was not affected by further increase in V^v concentration. Maximum grafting yield was achieved at pH 2; grafting fell greatly at higher pH. The rate of grafting followed the order: 70° > 60° > 50°C. The graft yield increased significantly by increasing the MMA concentration from 0.5 to 5%. Of the solvents studied, n-propanol and isopropanol enhanced the grafting rate provided that a solvent/water ratio of 5 : 95 was used; a higher solvent ratio decreased the magnitude of grafting. Other solvents, namely, methanol, ethanol, n-butanol, and acetone, in any proportion, decreased the rate of grafting. With the monomer used, the graft yield followed the order: methyl methacrylate > methyl acrylate > methacrylic acid > ethyl methacrylate > acrylic acid. Also reported was a tentative mechanism for vinyl-graft copolymerization onto cotton fabric using cellulose thiocarbonate-V^v. © 1993 John Wiley & Sons, Inc.     

Peroxydiphosphate–metal ion–cellulose thiocarbonate redox system‐induced graft copolymerization of vinyl monomers onto cotton fabric

The grafting of methacrylic acid (MAA) and other vinyl monomers onto cotton cellulose in fabric form was investigated in an aqueous medium with a potassium peroxydiphosphate–metal ion–cellulose thiocarbonate redox initiation system. The graft copolymerization reaction was influenced by peroxydiphosphate (PP) concentration, the pH of the reaction medium, monomer concentration, the duration and temperature of polymerization, the nature of vinyl monomers, and the nature and concentration of metallic ions (activators). On the basis of a detailed investigation of these factors, the optimal conditions for the grafting of MAA onto cotton fabric with the said redox system were as follows: [Fe²⁺] = 0.1 mmol/L, [PP] = 2 mmol/L, [MAA] = 4%, pH‐2, grafting time = 2 h, grafting temperature = 70°C, and material/liquor ratio = 1 : 50. Under these optimal conditions, the graft yields of different monomers were in the following sequence: MAA ? acrylonitrile > acrylic acid > methyl acrylate > methyl methacrylate. The unmodified cellulosic fabric (the control) had no ability to be grafted with MAA with the PP–Fe²⁺ redox system. The percentage of grafting onto the thiocarbonated cellulosic fabric was more greatly enhanced in the presence of iron salts than in their absence. This held true when the lowest concentrations of these salts were used separately. A suitable mechanism for the grafting processes is suggested, in accordance with the experimental results. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1879–1889, 2003     

Grafting of N-methylolacrylamide onto flax/polyester fabric using ferrous cellulose thiocarbonate/H2O2 redox system

Graft copolymerization of N-methylolacrylamide onto flax/polyester blend fabric using ferrous cellulose thiocarbonate/H₂O₂ redox system was investigated under different conditions including hydrogen peroxide concentration (1?60 mmol/l), ferrous ammonium sulphate concentration (1?50 mmol/l), N-methylolacrylamide concentration (5?200%, based on weight of sample), polymerization time (10?90 min), temperature (20?50°C), and pH of the medium (1.1?11). The nitrogen content and/or the methylol content were used for calculation of graft yields. Results obtained indicated that graft yields, derived from nitrogen analysis, are higher the greater the H₂O₂ concentration increases till 40 mmol/l, then level off. On the other hand, graft yields derived from methylol content exhibit maximum value at 10 mmol/l H₂O₂. The results indicate also that grafting was highly favoured when it was carried out using 1 mmol/l ferrous ammonium sulphate and pH 4.4 at 30°C for 60 min. The apparent activation energy of the copolymerization reaction amounts to 9.74 kJ/mol. Furthermore, the graft yield increases by increasing N-methylolacrylamide concentration within the range studied. The work was further extended to include a comparison between the polymerization efficiencies of the ferrous cellulose thiocarbonate/H₂O₂ redox system and the ferrous/H₂O₂ redox system in inducing grafting of N-methylolacrylamide onto flax/polyester blend fabric. For this reason, the two systems were studied with respect to graft yield, homopolymer proportion, total conversion, graft efficiency, and homopolymer efficiency.     

Potassium permanganate/thioureadioxide redox system-induced grafting of methacrylic acid onto loomstate cotton fabric

Graft polymerization of methacrylic acid (MAA) to loomstate cotton fabric using the KMnO₄/thioureadioxide system as the initiator was studied under different polymerization conditions. The polymerization reaction was assessed with respect to graft yield, homopolymer, total conversion, and graft efficiency. The magnitude of each of these characteristics was found to depend upon parameters such as concentrations of KMnO₄, thioureadioxide, and MAA as well as liquor ratio, reaction time, and temperature of polymerization. Based on a detailed investigation of these parameters, the optimal condition for grafting is KMnO₄ 0.045 g/L, thioureadioxide 0.03 g/L, material to liquor ratio 1 : 30, MAA 100% (owf), temperature 80°C, and time 60 min. A reaction mechanism for the polymerization reaction is also reported. © 1995 John Wiley & Sons, Inc.     

Elucidation of the nanoparticle effect on the grafting of vinyl monomers onto cotton fabric

The grafting emulsion polymerization of vinyl monomers onto cotton was carried out in the presence of double‐modified montmorillonite clay. The obtained results show that grafting with glycidyl methacrylate/montmorillonite gave a higher rate of grafting than grafting with methyl methacrylate/montmorillonite in all clay percentages, and also, the grafting yield of glycidyl methacrylate monomer onto cotton in the presence of montmorillonite clay had a higher value than that in the absence of the clay for all factors studied. Cotton grafted with glycidyl methacrylate/montmorillonite with a graft yield of about 50% was prepared according to the emulsion polymerization technique and was treated with different concentrations of dibutylamine solutions ranging from 1 to 4%. The obtained samples were characterized according to nitrogen content, thermal stability, scanning electron microscopy, mechanical properties, water absorption, and color strength according to acid, basic, and reactive dyes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Graft copolymerization of methyl methacrylate and other vinyl monomers onto cotton fabric using ferrous cellulose thiocarbonate–N-bromosuccinimide redox initiation system

The cellulose thiocarbonate, in the fabric from, was treated first with a freshly prepared ferrous ammonium sulphate (FAS) solution. The sotreated fabric formed, with N-bromosuccinimide (NBS), an effective redox system capable of initiating grafting of methyl methacrylate (MMA) and other vinyl monomers onto the cotton fabric. The effect of the polymerization conditions the polymer criteria, namely, graft yeild, homopolymer, total conversion, and grafting efficiency, was studied. These polymer criteria were found to depend extensively upon concentrations of the Fe²⁺ ion (activator), NBS (initiator), and MMA; pH of the polymerization medium, and duration and temperature of polymerization. Based on detailed investigation of these factors, the optimal conditions for grafting were as follows: Fe²⁺, 1 × 10⁻³ mol/L; NBS, 1 × 10⁻² mol/L; MMA, 4%; pH, 2: polymerization time, 150 min; polymerization temperature, 60°C; material/liquor ratio, 1: 100. Under these optimal conditions, the rates of grafting of different vinyl monomers were in the following sequence: methyl methacrylate ≫ methyl acrylate > acrylonitrile. Other vinyl monomers namely, acrylic acid, and methacrylic acid have no ability to be grafted to the cellulosic fabric using the said redox system. A tentative mechanism for the polymerization reaction is suggested. © 1996 John Wiley & Sons, Inc.     

Grafting of acrylic monomers onto cotton fabric using an activated cellulose thiocarbonate–azobisisobutyronitrile redox system

The feasibility of a cellulose thiocarbonate–azobisisobutyronitrile (AIBN) initiation system to induce graft copolymerization of methyl methacrylate (MMA) and other acrylic monomers onto cotton fabric was investigated. Other acrylic monomers were acrylic acid, acrylonitrile, and methyl acrylate. The initiation system under investigation was highly activated in the presence of a metal‐ion reductant or a metal‐ion oxidant in the polymerization medium. A number of variables in the grafting reaction were studied, including AIBN concentration, pH of the polymerization medium, nature of substrate, monomer concentration, duration and temperature of polymerization, and composition of the solvent/water polymerization medium. The solvents used were methanol, isopropanol, 1,4‐dioxane, cyclohexane, benzene, dimethyl formamide, and dimethyl sulfoxide. There were optimal concentrations of AIBN (5 mmol/L), MMA (8%), Fe²⁺ (0.1 mmol/L), Mn²⁺ (8 mmol/L), and Fe³⁺ (2 mmol/L). A polymerization medium of pH 2 and temperature of 70°C constituted the optimal conditions for grafting. The methanol/water mixture constituted the most favorable reaction medium for grafting MMA onto cotton fabric by using the Fe²⁺–cellulose thiocarbonate–AIBN redox system. MMA was superior to other monomers for grafting. The unmodified cotton cellulose showed very little tendency to be grafted with MMA compared with the chemically modified cellulosic substrate. A tentative mechanism for the grafting reaction was proposed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1261–1274, 2004     

A system for polymerising acrylonitrile onto loomstate cotton fabric using potassium permanganate/citric acid

A novel chemical formulation for concurrent grafting and dyeing using a potassium permanganate/citric acid system to induce polymerisation of acrylonitrile onto loomstate cotton fabric is described. The critical properties of the fabric, such as graft yield, colour strength before and after soaping and percentage loss in colour strength due to soaping were found to depend upon the concentrations of potassium permanganate, citric acid and acrylonitrile, as well as pH of the treatment bath and the duration of the treatment.     

Solid state grafting copolymerization of acrylamide onto poly(vinyl alcohol) initiated by redox system

A solid state grafting copolymerization of acrylamide (AM) onto poly(vinyl alcohol) (PVA) was conducted with ammonium persulfate and sodium bisulfite redox system as initiators. Before the reaction the PVA powder and required amount of AM were mixed evenly, and sprayed with water to swell the PVA powder and to dissolve AM. Then the swollen PVA powder was sprayed with the redox solution, and the reaction temperature was controlled at a temperature between 30°C and 80°C for 120 min. The grafting percentage and efficiency were determined as functions of monomer/PVA ratio, initiator concentration and reaction temperature. The structure and performance of the graft copolymers were confirmed by FTIR‐ATR, XRD, ¹³C NMR, and thermogravimetric analysis, together with mechanical property and apparent viscosity measurements. It has been confirmed that grafting copolymerization of AM onto PVA initiated by this redox system occurred with higher grafting percentage and efficiency in the solid state. The thermal stability and water‐solubility of grafted PVA were found to be better than those of unmodified PVA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39938.     

Graft copolymerization of vinyl monomers onto modified cotton. IX. Hydrogen peroxide–thiourea dioxide redox system induced grafting of 2-methyl-5-vinylpyridine onto oxidized celluloses

Cotton cellulose was independently oxidized with potassium periodate, potassium dichromate-sulfuric acid, and potassium dichromate–oxalic acid, and the resulting oxidized celluloses were further modified by treatment with chlorous acid or sodium borohydride. The various modified celluloses so obtained were grafted with 2-methyl-5-vinylpyridine using a thiourea–dioxide–H₂O₂ redox system. It was found that the initiation characteristics of the cellulose samples vary widely with the oxidizing agent used. Further modification of the oxidized celluloses by treating them with chlorous acid enhances considerably their susceptibility toward grafting. The opposite holds true when these oxidized celluloses were modified by sodium borohydride treatment. Excluding thiourea dioxide from the polymerization system offsets grafting onto cotton cellulose while considerable grafting takes place on the various oxidized celluloses and their further modified samples. The work was also extended to study the factors which affect the graft uptake, homopolymer formation, and total conversion. In addition, the reactions involved in initiation of grafting were elucidated.     

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,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.     

A method for determining boron in cotton fabric

A technique involving radiofrequency-discharged oxygen has been demonstrated in the analysis for boron in cotton fabric as well as preparation of residual ash replicas of identical three-dimensional configuration of the original sample for microscopic studies. The main advantages of this technique lie in its simplicity and fastness.     

A simple technique for grafting poly(methyl methacrylate) onto glass fabric

We have developed a two-step technique for synthesizing dichlorosuccinyl peroxide at room temperature, starting from succinic anhydride. It reacts with silanated glass fabric or beads at room temperature. The macroinitiator thus formed can be used for the polymerization of methyl methacrylate, MMA. We show that the MMA is grafted to the surface of glass giving a chemically bonded ultrathin coating, as confirmed by the FTIR analysis and electron micrography.     

Homogeneous grafting reaction of vinyl pyrrolidone onto chitosan

Modification of chitosan by grafting of vinyl pyrrolidone (VP) was carried out in homogeneous phase using potassium persulfate as redox initiator. The effect of the reaction variables on the extent of grafting was studied systematically. Values for grafting percentages up to 290% were reached. It was observed that the solubility of chitosan was markedly reduced after grafting with vinyl pyrrolidone. The grafted product is insoluble in common organic solvents as well in dilute organic and inorganic acids. However, the solubility of the grafted chitosan after adsorption of copper ions changed substantially, becoming completely soluble in dilute hydrochloric acid. This was attributed to the effect of complex formation produced by coordination of amino groups of chitosan with copper ions. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1321–1326, 1997     

Grafting of vinyl monomers onto silk using redox systems. Yellowing of silk

The aim of this study is to investigate the influence of temperature, initiator concentration, and vinyl monomer on silk yellowing during grafting. A series of silk fabrics was treated at four different temperatures (70, 75, 80, and 88°C), with different concentrations of initiator in the range 1–4% owf, with and without methacrylamide (MAA) or 2-hydroxyethyl methacrylate (HEMA). By treating silk with ammonium persulphate (APS), in the absence of a monomer, the degree of silk yellowing increased linearly with increasing both initiator concentration and treatment temperature, indicating that the initiator plays a specific role in enhancing silk yellowing through macroradical formation. The graft copolymerization of MAA (with APS as the initiator) caused only slight changes in the intensity of silk yellowing compared to blank-treated fabrics. On the other hand, the use of HEMA resulted in a deeper yellowing of silk fabrics, especially in the 70–80°C temperature range, due to its higher reactivity and to the tendency to form a homopolymer, leaving unreacted macroradicals on silk fibroin backbone. Compared to APS, other initiators, such as 2,2′-azobis(isobutyronitrile) (AIBN) and 2–2′-azobis-(2-amidino propane) dihydrochloride (ADC), caused a significantly lower degree of silk yellowing when tested in the absebce of a monomer. The yellowness of silk fabrics tended to increase by grafting with HEMA, while decreased by grafting with MAA. The use of variable amounts of monomer (25–150% owf) did not influence the degree of yellowing with ADC as the initiator. The results reported in this study show that the extent of yellowing induced on silk fabrics by grafting MAA and HEMA with APS as the initiator can be limited by a suitable selection of the processing parameters (initiator concentration, temperature). Moreover, the use of both AIBN and ADC appears promising, owing to their negligible effect on silk yellowing. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 239–246, 1998     

A novel method for fabric color transfer

Fabric color design is a complex process in textiles and clothing industry. A new method for fabric color selection and transferring is proposed in this study. An automatic way to select the colors from the natural images is developed for fabric color design. Based on these colors, a fabric image is then used for color transferring. The fabric image is processed by a bias field estimation operation, and the membership function of the color deviations of the image has been obtained. According to the selected colors and the color membership function, the fabric image colors can be changed and transferred to a new image that preserves the similar texture appearance but with significantly different color effects. The experimental results confirm the effectiveness of the proposed method. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 304–310, 2015     

Synthesis and characterization of novel biocidal cyclodextrin inclusion complexes grafted onto polyamide‐6 fabric by a redox method

The synthesis of immobilized β‐cyclodextrin derivatives onto polyamide‐6 fabric is presented. These novel fabrics were prepared by graft‐copolymerization of glycidyl methacrylate (GMA) onto polyamide 6 fabric, using a chemical redox system K₂S₂O₈/CuSO₄·5H₂O, followed by reaction of β‐cyclodextrins (CD) or monochlorotriazinyl (MCT β‐CD) with the GMA epoxy group. Some biocidal guests were complexed into CD cavity including p‐hydroxy benzoic acid, AgNO₃–ethanolamine mixture, iodine, N,N‐diethyltoluamide (DETA), citronella, jasmine, and sweet basil. Characterization of the novel fabrics was done by Fourier transform infrared spectroscopy (IR), electron scanning microscopy (SEM), and thermo gravimetric analysis (TGA). The biocidal activity of the grafted fabrics was tested against five strains of microorganisms. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 2586–2593, 2006     

过硫酸盐引发棉纤维接枝的研究

以过硫酸盐与硫代硫酸钠为引发剂,使丙烯酰胺与棉纤维进行接枝共聚,研究了过硫酸盐的加入方式和加入量对接枝反应的影响,发现采用过硫酸铵与过硫酸钾两种氧化剂、两步加入的办法能够克服体系中氧气的阻聚作用,又能得到较高的单体转化率和接枝率。