γ-Radiation induced graft copolymerization of N-phenyl- and N-p-hydroxyphenyl maleimide onto cotton fabrics

The graft copolymerization of N-phenylmaleimide and its p-hydroxy derivative onto cotton fabric using γ-radiation was studied. The effects of monomer concentration, dose rate, and irradiation time have been investigated. The surface topology, the x-ray diffraction, and the thermal stability of the modified fabric also were studied. In addition, the dyeing characteristics of the grafted fabrics when dyed with basic dyes together with the color fastness of these dyes towards UV radiation were investigated.     

Radiation‐induced graft copolymerization of methylmethacrylate onto poly(tetrafluoroethylene‐co‐ethylene) film

Modification of poly(tetrafluoroethylene‐co‐ethylene), Tefzel (ETFE), film has been carried out by grafting methylmethacrylate (MMA) by radiation method including preirradiation and double‐irradiation methods. Percentage of grafting has been determined as a function of the (i) total dose, (ii) monomer concentration, (iii) amount of liquor ratio, (iv) reaction time, and (v) temperature.The effect of different alcohols such as methanol, ethanol, 2‐propanol, n‐butanol, n‐pentanol, and 2‐ethoxy ethanol on percentage of grafting of MMA was also studied. The graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis (TGA). Methylmethacrylate produces higher percentage of grafting by preirradiaton method than double‐irradiation method. MMA‐grafted ETFE films (S_irr), i.e., prepared by preirradiation involving single irradiation show better thermal stability than MMA‐grafted ETFE films (D_irr), i.e., prepared by double irradiation and unmodified ETFE film. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

In situ polymerization of aniline on acrylamide grafted cotton

In this article, polyaniline (PANI)/cotton composite were prepared by in situ polymerization on the grafted cotton. First, acrylamide was grafted onto cotton cellulose using a radical graft polymerization process and some influencing factors were studied. Then polyaniline/cotton conductive composite fabrics were prepared by chemical in situ polymerization on the grafted cotton. The influences of the concentration of ammonium persulfate, aniline, hydrochloric acid, and the reaction time to the conductivity and K/S of composite fabric were studied. By contrasting, graft brought on an improvement of about one order of magnitude to the conductivity of composite fabric. The strength, TG, FTIR‐ATR, and SEM of prepared fabric were measured. The thermal stability and tear strength of composite fabric reduced, whereas PANI exhibited a rough but uniform, coherent PANI coating on surface of cotton fiber. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Jute composite with MMA by gamma and UV radiations in the presence of additives

Jute yarns treated with MMA + MeOH solutions were irradiated either with Co‐60 gamma source or with UV radiation. In gamma radiation, polymer loading of MMA (methyl methacrylate) onto jute increased quite substantially, but the strength of the composite decreases sharply after 15% polymer loading. The gamma‐treated jute samples were very brittle. On the other hand, jute yarns irradiated in situ under UV radiation was found to be grafted with MMA. The tensile strength of the UV‐cured jute yarn composite increases with an increase of grafting level, in contrast to the behavior observed with the gamma‐irradiated jute composite samples. The tensile properties of the composites can be further enhanced by the incorporation of certain additives and coadditives into MMA + MeOH solutions. This opens diverse applications for jute materials. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 900–906, 1999     

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.     

Gentamicin‐loaded poly(acrylic acid)‐grafted cotton fibers,part 1: Synthesis,characterization, and preliminary drug release study

This study describes preparation of poly (acrylic acid)‐grafted cotton fibers and release of antibiotic drug gentamicin sulfate from them under physiological conditions. Poly(acrylic acid) has been grafted onto cellulose backbone of cotton fibers via Ce(IV)‐initiated polymerization in aqueous medium. The conditions obtained for optimum grafting were as follows: initiation time 30 min; initiation temperature 37°C; monomer concentration 27.8 mM; grafting temperature 30°C; nitric acid (catalyst) concentration 0.1M. The grafted fibers were characterized by FTIR, TGA, and SEM analysis. The antibiotic drug gentamicin sulfate (GS) was loaded into the grafted fibers by equilibration method and release was studied under physiological conditions. The kinetic release data was interpreted by first‐order kinetic model. Finally, drug‐loaded fibers showed fair antibacterial action against Escherichia coli. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

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     

UV‐radiation–induced preirradiation grafting of methyl methacrylate onto lignocellulose fiber in an aqueous medium and characterization

The preirradiation method of grafting has been established by ultraviolet radiation. Methyl methacrylate (MMA) was grafted onto jute fiber in an aqueous medium. The variation of graft weight with UV‐radiation time, monomer concentration, and reaction time was investigated. The conversion of monomer into homopolymer and graft copolymer was evaluated. The graft weight passes through a maximum value (～ 122%) with UV‐radiation time. The optimum value of the monomer concentration was evaluated for maximum degree of grafting. Graft copolymerization of MMA onto lignocellulose fiber significantly increases the elongation at break (～ 65%) compared to that of the “as‐received” sample. However, a linear decrease on breaking load was observed with the increase of graft weight. The estimation of degree of grafting was achieved using an IR technique by correlating band intensities with the degree of grafting. Considering the water‐absorption property, the grafted sample showed a maximum up to 61% decrease in hydrophilicity compared to that of the as‐received sample. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1667–1675, 2004     

Radiation grafting of methyl methacrylate monomer on natural rubber latex

A method of radiation grafting of methyl methacrylate (MMA) monomer on natural rubber (NR) latex has been studied. The irradiation dose in radiation emulsion polymerization of MMA monomer was lower compared to the irradiation dose for grafting of MMA monomer on NR latex, in order to obtain the same degree of conversion. This is due to the size of the rubber particles which are quite large and, hence, not sufficient to ensure an ideal emulsion polymerization. The irradiation dose for radiation grafting of MMA monomer on latex was around 300 krad to obtain a 75% degree of conversion. However, this irradiation dose was lower compared to the irradation dose for bulk polymerization of MMA monomer, in order to obtain the same degree of conversion. This is due to the gel effect in the viscous media. Radiation grafting of MMA monomer on NR latex does not influence the pH of the latex, but influences the viscosity significantly. The viscosity of the NR latex increased with an increase in irradiation dose, due to the increase of the total solid content in the latex. The MMA monomer converted to P-MMA in NR latex was largely grafted on the NR, or at least insoluble in a solvent for P-MMA, such as acetone or toluene. The hardness of the pure gum vulcanizate with an increase in the degree of grafting or P-MMA content, but the other physical properties, such as tensile strength, modulus, elongation at break, and thermal stability, were not greatly influenced by the degree of grafting.     

Modification of cellulosic fabrics to impart flame retardancy properties

Graft copolymerization of dimethylaminoethyl methacrylate (DMAEMA) onto cotton‐cellulose in the fabric form was carried out using a cellulose‐thiocarbonate‐ammonium persulphate redox initiation system. Effects of the concentration of the monomer, effect of liquor ratio, grafting time, and temperature were studied. The results point out the following important aspects of flame retardation of cellulose fabrics. (1) The graft polymerization of DMAEMA can improve the flame retardant properties of cellulose fabrics. (2) Tertiary amine grafted to cellulosic fabrics is suitable for nitrogen compounds that can effectively operate as synergists. The flame retardant properties of the poly‐DMAEMA‐ grafted‐phosphorylated cellulosic materials were found to be excellent even after 25 dry clean washings. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis,film morphology,and performance of cationic fluorinated polyacrylate emulsion with core-shell structure

A novel cationic fluorinated polyacrylate emulsion (CFBDH) was prepared by polymerization of dodecafluoroheptyl methacrylate (DFMA) with butyl acrylate (BA), dimethylaminoethyl methacrylate (DM), and 2-hydroxypropyl acrylate (HpA) via seeded emulsion polymerization. Chemical structure, particle morphology, glass transition temperature, and thermal property of resultant CFBDH were characterized by FTIR, ¹H-NMR, TEM, DSC, and TGA, respectively. The as-synthesized product was utilized to treat the clean glass sheet and cotton fabric substrates, then morphology, components, hydrophobicity, and other performances of films on those substrates were investigated by SEM, AFM, XPS, and contact angle meter, etc. Results show that the target product possesses anticipative structure and its latex particles have uniform spherical core-shell structure with an average diameter of 126 nm. The core-shell CFBDH latex film thus has two T_g and its thermal property has been improved due to the introduction of fluorine-containing acrylate monomer. The CFBDH film on cotton fabric surface seems to be smooth compared to the blank by SEM. However, the CFBDH film on silicon-wafer is inhomogeneous and has many low or high peaks. At 2 nm data scale and in 1 μm² scanning field, the root mean square roughness of CFBDH film reaches to 0.205 nm. XPS analysis indicates the perfluoroalkyl groups have the tendency to enrich at the film-air interface. In addition, CFBDH can provide good hydrophobicity for the treated fabric and do not influence whiteness of the treated fabric indeed. However it will make the treated fabric slightly stiff at high doses. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Grafting of 2-(dimethlamino) ethyl methacrylate onto gamma irradiated polypropylene fabric

Polypropylene fabric was gamma pre-irradiated at doses of 1,2 and 3 Mrads. The irradiated fabric was grafted with an aqueous solution of 2-(dimethylamino) ethyl methacrylate. The graft yield was studied as a function of the different variable conditions such as storage time, monomer concentration (10–40%), reaction time, and temperature (50, 70, 100°C). The grafted polypropylene was further quaternized with dimethyl sulphate or monochloroacetic acid. The grafted and quarternized fabrics were dyed with an acid dye. The fixation properties of the dyed samples were determined by DMF extraction. The moisture regain and mechanical properties were also measured.     

PP无纺布辐射接枝MMA的研究

采用聚丙烯(PP)无纺布为基材,甲基丙烯酸甲酯(MMA)为单体,~(60)Co-γ射线预辐射接枝共聚的方法制备接枝共聚物,讨论了辐射剂量、反应温度、反应时间、单体浓度、阻聚剂和交联剂的用量等对接枝率的影响。结果表明,接枝反应的最佳条件为:辐射剂量60 kGy以上、接枝温度65℃、接枝时间2 h、MMA质量分数20%、交联剂质量分数5%、阻聚剂用量0．3g,该条件下PP的接枝率为6．5%。     

Gamma radiation-induced graft copolymerization of divinylbenzene onto cellulose fabric

The extent of DVB grafting onto cellulose fabric increases with total gamma radiation dose up to 10–15 kGy while it decreases with the radiation dose rate. A quantitative analysis of DVB grafting has been attempted by means of IR spectroscopy using the baseline method. Characteristic bands were selected in the spectra of copolymers, namely, the cellulose band at 1160 cm^?1 and DVB band at 798 cm^?1. The former band decreased and the latter increased with the degree of copolymerization, and the values were in accordance with the calibration straight line. An attempt to graft DVB onto cotton fabric previously grafted with styrene showed greater extent of copolymerization than with pure fabric.     

Radiation-induced grafting of functional acrylic monomers onto polyethylene and polypropylene films using acryloyl chloride

Summary Radiation-induced graft polymerization of acryloyl chloride onto films of polyolefins (polyethylene and polypropylene) using gamma radiation was investigated in order to establish a convenient method to obtain polymer films grafted with polyacrylic esters. Grafting was carried out by three different methods; (i) direct irradiation of film in monomer solution (ii) vapor phase irradiation method, and (iii) pre-irradiation in air. The effects of monomer concentration, radiation dose and methods of grafting, on the formation of grafted polyolefins are reported in this paper. Received: 5 April 2000/Revised version: 17 November 2000/Accepted: 20 November 2000     

Grafting of methyl methacrylate to nitrocellulose by ceric ions

Studies were carried out on grafting of various vinyl monomers to nitrocellulose by ceric ions. It was observed that graft copolymerization occurred only with methyl methacrylate (MMA) and methyl acrylate monomer. The variables such as initiator concentration, monomer concentration, time of grafting, and nitrocellulose content on grafting of MMA are discussed. By hydrolyzing away the nitrocellulose backbone, the grafted poly(methyl methacrylate) branches were isolated and the >c?o peak at 1740 cm^?1 in the infrared spectra of these isolated branches gave definite evidence of grafting. The molecular weight of isolated branches has been determined by viscometry. The probable mechanism of grafting may be at the α-carbon atom of primary alcohol or at a C₂-C₃ glycol group of the anhydro glucose unit or at the hemiacetal group of the end unit of nitrocellulose, as nitrocellulose is formed by the partial nitration of cotton cellulose.     

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.     

Cotton fabric graft copolymerization using microwave plasma. II. Physical properties

Microwave plasma treatments were applied to lightweight cotton fabric with oxygen, nitrogen, and argon at various microwave power levels and exposure times. The results showed significant effects from the type of plasma, microwave power, and treatment time on the fabric weight loss. Oxygen plasma treatment generates higher weight loss than argon plasma and nitrogen plasma. The breaking strength of the treated fabric was affected mainly by longer exposure time to the plasma. The active centers created within the cellulose macromolecules were used to initiate copolymerization reactions with the vinyl laurate monomer [CH₃(CH₂)₁₀COOCH?CH₂]. The grafted cotton fabric showed excellent water repellency properties. Repeated home laundering of the treated cotton fabrics revealed no significant effect on the water contact angle or on the quantity of grafted vinyl laurate monomer as determined by universal attenuated total reflectance Fourier transform IR, demonstrating the good durability of the treatment that was applied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 896–902, 2005     

Thermal behavior of cellulosic graft copolymers. II. Cotton grafted with binary mixtures of vinyl acetate and methyl acrylate

Thermal degradation of cotton, mercerized cotton, cotton grafted with vinyl acetate-methyl acrylate mixtures at different compositions, and mercerized cotton grafted with vinyl acetate–methyl acrylate mixture at a composition of 60 : 40 has been investigated using the techniques of thermogravimetric analysis (TGA) and differential thermal analysis (DTA) in nitrogen. The kinetic parameters E, n, and A have been obtained following several methods of thermogravimetric analyses. The mercerization shows a little effect upon thermic properties of cotton cellulose, making cotton thermally more stable. Graft copolymerization of vinyl acetate-methyl acrylate mixture makes cotton thermally less stable if the composition of the copolymer grafted is 100, 90, and 70 mol % VA, while in the case of cellulose graft copolymers with compositions of VA–MA of 80 : 20, 20 : 80, 5 : 95, and 0 : 100 the thermal stability is higher than that of original cotton. The thermal stability of the mercerized cotton grafted with vinyl acetate-methyl acrylate mixture with a composition of 60 : 40 depends on the percent grafting yield. The thermal stability of mercerized cotton grafted with the monomer mixture is higher than that of cotton grafted with that monomer mixture. The degradation of cellulose and cellulose graft copolymers is complex as is shown by DTA thermograms and kinetic parameters.     

Radiation-induced grafting of N,N′-dimethylaminoethylmethacrylate onto chitosan films

Chitosan films were grafted with N,N ′-dimethylaminoethylmethacrylate using the ⁶⁰Co gamma irradiation method. The effect of solvent composition, monomer concentration, dose rate, and total dose on grafting was studied. The solvent composition has a marked effect on the degree of grafting. Maximum yield was obtained in the water-methanol (1 : 1) system. The percent grafting increased with monomer concentration and was found to be higher at a lower dose rate for a constant total dose of 0.216 Mrad. The tensile strength, crystallinity, and degree of swelling of grafted films decreased on increasing graft level. However, the graft copolymers showed improved thermal stability. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 869–877, 1997