Radiochemical graft copolymerization of methacrylonitrile and binary mixture of methacrylonitrile with 4-vinylpyridine onto isotactic polypropylene fiber

Graft copolymerization of methacrylonitrile (MAN) and its binary mixture with 4-vinylpyridine (4-VP) onto isotactic polypropylene (IPP) fiber has been studied in aqueous medium by the preirradiation method. Optimum conditions for obtaining the maximum percentage of grafting have been evaluated. Rate of grafting (Rg) has been determined as a function of total initial monomer concentration. The graft copolymers are characterized by IR spectroscopy, by thermogravimetric analysis, and by isolating the polymer from the graft copolymer. The effect of MAN, an acceptor monomer, on percentage of grafting of 4-VP, a donor monomer, has been discussed in the light of the mechanism proposed for grafting by the radiochemical method. © 1994 John Wiley & Sons, Inc.     

Reactivity ratios during radiation‐induced grafting of comonomer mixtures onto polyester fabrics

Radiation‐induced grafting of binary mixtures of acrylonitrile (AN)/styrene (S) and acrylamide (AAm)/styrene (S) onto polyester fabric (PET) has been investigated. Synergism during radiation grafting was investigated by determining the graft yield fraction for each monomer in the final graft copolymer. Moreover, by knowing the mole fraction of each monomer in the grafting solution, the reactivity ratio of the individual monomers in the comonomer mixture during graft copolymerization could be determined: in the case of AN/S comonomer mixture, the calculated reactivity ratios for AN and S are 0.04 and 0.05, respectively; the calculated reactivity ratios of AAm and S in their comonomer mixture are 1.82 and 0.41, respectively. © 2001 Society of Chemical Industry     

Graft copolymerization of 4-vinylpyridine and methyl acrylate onto polyethylene film by radiochemical method

Graft copolymerization of 4-vinyl pyridine (4-VP) and methyl acrylate (MA) onto polyethylene (PE) was studied in aqueous medium in air by the mutual irradiation method. The percentage of grafting was determined as a function of the (i) total dose, (ii) monomer concentration, and (iii) amount of water. The effect of different alcohols such as methanol, ethanol, isopropyl alcohol, butanol, and pentanol on the percentage of grafting of 4-VP and MA was studied. The effects of different amines on the percentage of grafting of 4-VP were also studied. The graft copolymers were characterized by IR spectroscopy and thermal analysis and by identifying the isolated polymer from the grafted film. Grafted PE film was tested for permeability behavior and was found to be permeable to a 0.5% aqueous sodium chloride solution. A plausible mechanism is suggested to explain the grafting of 4-VP and MA onto PE film. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 599–610, 1998     

4-Vinylpyridine and 2-hydroxyethylmethacrylate monomer mixture graft copolymerization onto poly(ethylene terephthalate) fibers using benzoyl peroxide

Summary Poly(ethylene terephthalate) (PET) fibers were grafted with 4-vinyl pyridine (4-VP) and 2-hydroxyethylmethacrylate (HEMA) using benzoyl peroxide (Bz₂O₂) as initiator in aqueous media. PET fibers were swelled in dichloroethane (DCE) for 2 h at 90 °C to promote the incorporation and the subsequent polymerization of 4-VP/HEMA onto PET fibers. Variations of graft yield with time, temperature, initiator concentration and monomer mixture ratio were investigated. The optimum initiator concentration was found to be 8×10^-3 mol/L. The maximum graft yield was obtained 280%. The optimum temperature and polymerization time was found to be 85 °C and 100 min. respectively. The rate of grafting was found to be proportional of the 1.5 and 0.3 powers of 4-VP/HEMA and Bz₂O₂ concentrations, respectively. The grafted PET fibers were characterized by thermo gravimetric analysis and scanning electron microscopy (SEM). Further changes in properties of grafted PET fibers such as water absorption capacity, intrinsic viscosity and diameter were determined. The dye ability of the PET fibers increased with an increase in grafting with diazo and basic dyes.     

Functionalization of cotton fabric orienting towards antibacterial activity

The primary objective of modifying cotton fabric was to impart bactericidal properties to attract various fields such as defence, space and textile industrial applications. Chemically initiated graft copolymerization of 4-vinyl pyridine (4-VP) and acrylonitrile (AN) onto cotton fabric was carried out using ceric ammonium nitrate as a redox initiator. Optimum conditions pertaining to maximum percentage of grafting were evaluated as a function of concentration of initiator [CAN], concentration of nitric acid, monomer concentration, water, temperature and reaction time. Maximum grafting of 4-VP (51.63%) and AN (69.23%) was obtained respectively at optimum [ \textCAN ] = 2.738 ×10 ^{- 2} \left[ {\text{CAN}} \right] = 2.738 \times {10^{ - 2}} and 2.19 × 10⁻² moles/L, [ 4 - \textVP ] = 47.55 ×10 ^{- 22}\textmoles/\textL \left[ {4 - {\text{VP}}} \right] = 47.55 \times {10^{ - 22}}{\text{moles}}/{\text{L}} , [ \textAN ] = 18.85 ×10 ^{- 22}\textmoles/\textL \left[ {\text{AN}} \right] = 18.85 \times {10^{ - 22}}{\text{moles}}/{\text{L}} , [ \textHN\textO₃ ] = 11.9 ×10 ^{- 2} \left[ {{\text{HN}}{{\text{O}}_3}} \right] = 11.9 \times {10^{ - 2}} and 89.5 × 10⁻²² moles/L in 20 and 25 ml of water at an optimum temperature 70 °C and 60 °C with in 180 and 120 min. Antibacterial properties were induced into the modified cotton fabric by treating the grafted fabric with benzyl chloride. The grafted and quaternized copolymer were characterized by FTIR and Thermogravimetrical analysis. The bactericidal action of cotton fabric was tested by filtration test and it was observed that fabric grafted with 4-VP was more effective and efficient antibacterial as compared to AN grafted cotton sample.     

Multiresponsive polymeric particles with tunable morphology and properties based on acrylonitrile (AN) and 4-vinylpyridine (4-VP)

We report the synthesis of amphiphilic, pH and magnetic field sensitive polymeric particles obtained from the modification of poly(acrylonitrile-co-4-vinylpyridine) (p(AN-c-4-VP)) core-shell nanoparticles. The magnetic metal nanoparticles were encapsulated in the microemulsion during the polymerization to achieve magnetic-p(AN-c-4-VP)-composites with various morphology. We further chemically modified each component of p(AN-c-4-VP) particles and its composite to tune the hydrophilicity of the particles. Modification of nitrile (hydrophobic) groups to amidoxime (hydrophilic) groups by amidoximation reaction on AN, and quarternization of nitrogen on pyridine ring of 4-VP were carried out to tune the hydrophilicity and the charge of the particles. The modification also performed on magnetic responsive composites after inclusion of separately prepared magnetic Fe₃O₄ nanoparticles. It was further demonstrated that these multiresponsive particles can be used as drug carrier. A nonsteroidal and anti-inflammatory drug Naproxen was used as a model active agent for drug loading and the release studies from (p(AN-c-4-VP) based particles in phosphate buffer solution (pH = 7.4) at ambient temperature.     

Radiation grafting of N,N-dimethylaminoethylmethacrylate and 4-vinylpyridine onto polypropylene by the one- and two-step methods

Summary Radiation grafting of N,N-dimethylaminoethylmethacrylate (DMAEMA) and 4-vinylpyridine (4-VP) from the 50% monomers solutions in toluene and dichloroethane onto polypropylene (PP) films was carried by their mutual γ-irradiation (one-step method). In the two-step method, the grafting of DMAEMA or 4-VP from their solutions in toluene was performed onto PP modified preliminary with the other polymer (poly4-VP or polyDMAEMA). It has been found that chemical structure of PP modified with the first grafted polymer affected the efficiency of the other monomer grafting by the second step. Received: 30 April 2001/Revised version: 21 October 2001/Accepted: 28 November 2001     

Preparation of chelating fabrics by radiation‐induced grafting of itaconic acid and acrylonitrile onto polypropylene nonwoven fabrics and subsequent amination of graft copolymer

A mixture of acrylonitrile (AN) and itaconic acid (IA) was cografted onto polypropylene (PP) nonwoven fabrics by preirradiation method. The effects of graft polymerization conditions such as temperature, reaction time, Mohr's salt concentration, solvent mixture ratio, and comonomer composition on the total grafting yield were investigated. The addition of AN as a comonomer increased the amount of IA that reacted with PP fabrics. An increase in the temperature from 40 to 60°C increased the grafting rate, but the final grafting yield decreased at high temperature. The addition of 0.01 wt % Mohr's salt to the reaction medium leaded to a sharp increase of grafting yield. The accelerative effect of solvent medium on the grating yield was higher in dimethylformamide (DMF) and methanol mixtures, when compared with DMF or methanol. Chelating fabrics was synthesized by subsequent amination of grafted fabric with ethylene diamine (EDA) and phenylhydrazine (PH). The conversion yield reached maximum value at about 90% for 80% PP‐g‐AN‐IA fabrics at 90°C. At same amination conditions, the conversion yield is higher when PP‐g‐AN‐IA fabrics react with EDA compared with PH. FT‐IR data indicate that amine groups were introduced onto PP‐g‐AN‐IA fabric through amide linkage between grafted AN or IA and EDA or PH. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation of quaternized poly(vinylidene fluoride) membranes by γ-ray irradiation induced graft polymerization and their antibacterial property

PVDF microfiltration membranes were modified by γ-ray irradiation induced grafting polymerization of 4-vinyl pyridine (4-VP) and then quaternization by n-butyl chloride. The effects of grafting method (simultaneous irradiation, pre-irradiation/UV), grafting conditions (absorbed dose, UV irradiation time, and 4-VP concentration) and quaternization conditions (temperature, time, and concentration of n-butyl chloride) were investigated. It was found that, the grafting degree initially increases with the absorbed dose and then reaches a plateau. The optimal concentration of 4-VP is around 15 wt.%. The ion exchange capacity increases with quaternization temperature, time, and concentration of n-butyl chloride. After modification, the pores size, permeation flux, as well as elongation at break, of quaternized membrane decreases, while the retention coefficient, tensile strength and Young’s modulus increase apparently. Upon contacting with the membranes, the Escherichia coli concentration decreases gradually. It is the adsorption mechanism for the pristine membranes whereas contact-killing mechanism for the quaternized membranes. Simultaneous irradiation is more effective than pre-irradiation/UV in the improvement of antibacterial property of membranes.     

Synthesis and characterization of PET fibers grafted with binary mixture of 2-methylpropenoic acid and acrylonitrile by free radical: its application in removal of cationic dye

Grafting of binary vinyl monomer mixtures such as 2-methylpropenoic acid (MPA) and acrylonitrile (AN) onto poly (ethylene terephthalate) fibers (PET) was achieved in an aqueous medium with using benzoyl peroxide like free radical initiator. A new reactively fibrous adsorbent was used for removal of dye such as methylene blue (MB) from aqueous media through batch sorption method. Fibers adsorbent was swelled in solution to support the graft and the subsequent polymerization of MPA/AN onto polyester fibers. Optimum conditions for grafting were discovered and reactive fiber were characterized. Variations of graft yield with time, temperature, initiator concentration and monomer mixture ratio were investigated. The optimum initiator concentration was found to be 8 × 10^?3 mol/L. The percentage of grafting rose steadily with the vinyl monomer mixture monomer concentration (50 %). The optimum temperature and polymerization time were found to be 80 °C and 120 min, respectively. The use of AN and MPA monomers together in grafting produce a significant increased in the graft yield. Experimental studies showed that the percentage removal of MB was a great higher on the MPA/AN grafted PET (MPA/AN-g-PET) fibers than on the original PET fibers. The adsorbed quantity of MB improved with pH and basic pH was appropriate for the elimination of MB. MPA/AN-g-PET fibers removed 98 % of cationic dye when initial concentration diverse from 10 to 80 mg L^?1 at pH 9.0. Almost all of the adsorbed cationic dye was eluted by ethanoic acid in methanol. Ten removal–desorption cycles indicated that the reactive fibers were favorable for repetitive use without notable change in removal capacity. Consequently, the MPA/AN-g-PET fibers have demonstrated potential as an effective adsorbent for the extremely effective removal of cationic dyes from aqueous media.     

Thermal degradation of partially carboxymethylated cellulose grafted with 4-vinylpyridine

Partially carboxymethylated cellulose (PCMC) was grafted with 4-vinylpyridine (4-VP) using ceric ammonium nitrate (CAN) as initiator and the thermal behaviour of the grafted samples having different grafting yields was studied by means of thermogravimetric dynamic analysis (TGA). For comparison, the thermal behaviour of poly(4-vinylpyridine), P(4-VP), and the ungrafted cellulosic substrate were also examined. The activation energies were determined according to the Broido method. From the thermogravimetric curves the temperature range at which the main decomposition occurred was determined and showed that the thermal degradation of grafted samples was initiated at lower temperature than both PCMC and P(4-VP).     

Graft polymerization of 4-vinylpyridine onto cellulosic fibres by the ceric ion method,I. The reaction time effect

A study was made of the time affecting the ceric ion induced grafting of 4-vinylpyridine (4-VP) onto partially carboxymethylated cotton (PCMC) having different degrees of substitution (D.S.). For comparison the same monomer was grafted onto cotton and mercerized cotton. The grafting parameters of these copolymerization reactions were determined. The graft yields for PCMC were significantly higher than those for unmodified cotton and mercerized cotton. The degree of crystallinity of the graft copolymers and of the unmodified cotton and PCMC samples was determined by the X-ray method. The crystallinity index decreased with the presence of grafted polymer. The reaction time effect of the grafting of 2-VP on cotton was also studied.     

Swelling-assisted graft copolymerization of 4-vinyl pyridine on poly(ethylene terephthalate) films using a benzoyl peroxide initiator

Graft copolymerization of 4-vinyl pyridine (4-VP) on poly(ethylene terephthalate) (PET) films using a benzoyl peroxide (Bz₂O₂) initiator was investigated under different conditions including polymerization time, temperature, monomer concentration, and initiator concentration. Dimethyl sulfoxide (DMSO) was used as swelling agent to promote the incorporation and the subsequent polymerization of 4-VP to PET films. Maximum percent grafting was obtained when the polymerization was carried for a period of two hours at 65°C. Increasing the monomer concentration from 0.2M to 0.8M and Bz₂O₂ concentration from 1.0×10⁻³M to 2.5×10⁻³M was accompanied by a significant enhancement in percent grafting. Monomer diffusion on PET films and its effect on the grafting yield were studied and intrinsic viscosities of grafted films were also measured. © 1996 John Wiley & Sons, Inc.     

The ammonium nitrate with 15 WT% potassium nitrate-ethylenediamine dinitrate-nitroguanidine system

The phase diagram for the ternary system ammonium nitrate(AN) with 15 wt% potassium nitrate(AN:15KN)-ethylenediamine dinitrate(EDD)-nitroguanidine(NQ) has been determined from room temperature to the melting point. The ternary eutectic temperature, measured for a mixture containing 67.24, 25.30, and 7.46 mole% of AN:15KN, EDD, and NQ, respectively, was found to be 98.9 ·°C. The binary phase diagrams for the systems AN:15KN-EDD, AN:15KN-NQ, and EDD-NQ were also determined.     

Synthesis of graft copolymers of binary vinyl monomer mixtures onto acetylated Saccharum spontaneum L and characterization

Methylmethacrylate (MMA) + acrylamide (AAm), MMA + acrylonitrile (AN), and MMA + acrylic acid (AA) binary vinyl monomer mixtures were graft copolymerization onto acetylated Saccharum spontaneum L, was carried out and maximum graft yield (185.6 %) was found with MMA+AAm binary mixture. Synthesized graft co‐polymers were characterized with FT‐IR spectrophotometry, scanning electron microscopy (SEM), thermal analysis TGA/DTA/DTG, and X‐ray diffraction (XRD) techniques. Thermal stability of Ss‐g‐poly(MMA + AAm) was found to be more than that of natural, acetylated S. spontaneum fiber and other graft copolymers. Although on grafting, percentage crystallinity and crystallinity index were found to decrease but graft copolymers were found to exhibit more moisture, chemical, and thermal resistance. Also, it can be observed that the surface of the grafted fibers is highly rough in comparison with the ungrafted fiber. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Kinetics of swelling assisted grafting of 4-vinyl pyridine onto poly(ethylene terephthalate) fibers using a benzoyl peroxide initiator

Summary Poly(ethylene terephthalate) (PET) fibers were grafted with 4-vinyl pyridine (4-VP) using benzoyl peroxide (Bz₂O₂) as initiator. Fibers were swelled in dichloroethane (DCE) for 2 h at 90 °C to promote the incorporation and the subsequent polymerization of 4-VP onto PET fibers. Variations of graft yield with time, temperature, initiator and monomer concentrations were investigated. Percent grafting was enhanced significantly by increasing Bz₂O₂ concentration up to 2 × 1 0 ^-3 mol/L and then decreased upon further increase in initiator concentration. Increasing the 4-VP concentration up to 0.6 mol/L improves the graft yield significantly. The optimum temperature and polymerization time was found to be 50 °C and 2 h respectively. Further changes in properties of grafted PET fibers such as moisture absorption capacity and intrinsic viscosity were determined. Grafted PET fibers were charactarized by thermogravimetric analysis and scanning electron microscopy (SEM). Molar mass of the grafted chains was also determined.     

Development of amidoxime functionalized silica by radiation‐induced grafting

A novel amidoxime‐based silica adsorbent was prepared by using radiation‐induced grafting technique. Grafting of acrylonitrile (AN) on silanized silica that was silanized by vinyltriethoxysilane (VTES) was carried out in solvent‐free system. The grafting of AN was increased with increasing the absorbed dose and monomer concentration in the mixture. Grafting of 748% of AN was achieved at 20 kGy dose. The nitrile groups of acrylonitrile grafted silica (AN‐g‐S) were chemically converted into amidoxime groups. The structure of AN‐g‐S and its corresponding products was investigated by FTIR, SEM, TGA, BET, and XRD analysis. FTIR and EDX analysis confirmed the grafting of AN onto silica surface. The changed morphology of SEM images shows the presence polyacrylonitrile layers on silica particles. The adsorption application of amidoxime‐grafted silica (AO‐g‐S) was studied against Cu²⁺. Its adsorption capacity is strongly depended on the pH of the solution and 172 (mg/g) of Cu²⁺ uptake was obtained at pH 5.0. The developed adsorbent has potential application to remove heavy metal ions from aqueous solutions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45437.     

Antibacterial,flame retardant,and physico‐chemical properties of cotton fabric graft copolymerized with a binary mixture of acrylonitrile and 4‐vinylpyridine

Modification of cotton fabric has been carried out through chemically induced graft copolymerization of binary mixture of acrylonitrile (AN) and 4‐vinyl pyridine (4‐VP) using ceric ammonium nitrate, (CAN) as initiator. Maximum percentage of grafting (151.28%) has been obtained at [4‐VP] = 0.376 mol L^?1 and [AN] = 1.221 mol L^?1, [CAN] = 0.0255 mol L^?1 and [HNO₃] = 0.9585 mol L^?1 in 25mL of water at 70°C in 180 min. Post quarternization and phosphorylation reactions of the grey and grafted cotton fabrics have been carried out to study their antibacterial and flame retardant properties respectively. The fabrics have been characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The physico‐chemical properties such as wettability, moisture regain, crease recovery and tensile strength of the grey and grafted cotton fabric have also been evaluated. The modified fabric has been shown to exhibit excellent antibacterial and flame retarding properties with improved physico‐chemical properties except for the mechanical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40415.     

Separation and extraction of some heavy and toxic metal ions from their wastes by grafted membranes

Preparation and characterization of a series of ion‐exchange membranes for the purpose of separation and extraction of some heavy and toxic metal ions from their wastes were studied. Such ion‐exchange membranes were prepared by γ‐radiation grafting of acrylonitrile (AN) and vinyl acetate (VAc) in a binary monomer mixture onto low‐density polyethylene (LDPE) using the direct technique of grafting. The reaction conditions at which the grafting process proceeds successfully were determined. Many modification treatments were attempted for the prepared membranes to improve their ion‐exchange properties. The possibility of their practical use in waste‐water treatment to remove some heavy and toxic metal ions such as Pb²⁺, Cd ²⁺, Cu²⁺, Fe³⁺, Sr²⁺, and Li⁺ were investigated. These grafted membranes showed great promise for possible use in the field of extraction and removal of some heavy and toxic metals from their wastes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 849–860, 2001     

Kinetics study of radiation‐grafting of acrylic acid,acrylonitrile, and their mixture onto wool fabric

The effect of monomer concentration, exposure time, irradiation temperature, and weaving direction on the kinetics of grafting acrylic acid (AA), acrylonitrile (AN), and their mixture onto wool fabric has been studied at the dose rate of 1.38 Gy/s. The degree of grafting is found to depend on the methanol‐to‐water solvent ratio and fabric‐to‐liquor ratio. The grafting rate and rate constant are dependent on irradiation temperature, type of grafted monomer, and weaving direction. The grafting rates increase with the increase in irradiation temperature (276–308 K). The calculated activation energy is nearly the same (16.4–17.2 kJ mol^?1) and the preexponential rate constant is dependent on the type of grafted monomer. The grafting of AA, AN, and their mixture are confirmed from the dyeing affinity of grafted fabrics towards Sandocryl Blue (SB), a basic dye. The formation of wool grafts and structural changes resulting from grafting were verified by using FTIR spectrometry and X‐ray diffraction analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4328–4340, 2006