Radiation‐induced graft copolymerization of MMA monomer onto UHMWPE: Adhesion improvement

Graft copolymerization of methyl methacrylate monomer onto ultra high molecular weight polyethylene (UHMWPE) and acid‐etched UHMWPE was conducted using preirradiation method in air in the presence of a Mohr salt and sulfuric acid to improve adhesion to the bone cement. The grafted samples were characterized by Fourier transform infrared (FTIR) spectroscopy, gravimetric method, goniometry, and interfacial bonding strength measurements. The FTIR results showed the presence of ether, carbonyl, and hydroxyl groups for grafted films. The gravimetric results showed that the chromic acid etching and graft copolymerization had a synergetic effect so, the irradiated, then chromic acid etched at room temperature and grafted sample (Rad etch25) had the highest grafting degree. The interfacial bonding strength between UHMWPE and poly methyl methacrylate bone cement was considerably improved by graft copolymerization and chromic acid etching. The surface morphology was studied by scanning electron microscopy. The substitution of polar groups into the backbone of UHMWPE by chromic acid etching and graft copolymerization changed its contact angles with water and methylene iodide and increased its surface energy, as evidenced by contact angle measurements. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Grafted wood pulp containing quaternary ammonium group and its application in the removal of different anions from aqueous solution

Network wood pulp based on acrylonitrile (AN) has been chemically modified through different reactions to obtain group capable of anion exchange. Graft copolymerization of AN onto wood pulp was carried out by using γ‐radiation ⁶⁰Co. Factors affecting the grafting process, e.g., radiation dose and monomer concentration, was investigated. The chemical modification of cyano groups were carried out by reaction with ethanolamine producing oxazoline group followed by quaternization of tertiary amine by reaction with benzyl chloride producing quaternary ammonium salt. The grafted and modified wood pulp were characterized by FTIR, SEM, and TGA. Qualitative adsorption experiments were conducted to evaluate the ability of modified wood pulp to fix sulfate, phosphate, nitrate, and dichromate from aqueous solution using batch extractions. Based on the results obtained, it may be concluded that it is possible to modify chemically wood pulp containing cyano groups by different routes to use it as anion exchanger for different anions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3120–3128, 2007     

Radiation‐induced graft copolymerization of acrylic acid/acrylonitrile onto LDPE and PET films and its biodegradability

Graft copolymerization of acrylic acid/acrylonitrile (AAc/AN) comonomer onto low‐density poly(ethylene) (LDPE) and poly(ethylene terephthalate) (PET) films using direct radiation grafting technique has been investigated. The effect of different reaction conditions on the grafting yield was studied. The structure of the grafted films at different compositions was characterized by FTIR, TGA, SEM, and XRD. Biodegradation of grafted LDPE and PET was investigated by burial method in two types of Egyptian soils (agricultural and desert soils). The bacteria responsible for biodegradation were isolated and characterized, and the capacities for the growth on these polymers as substrates were compared. The isolates from agricultural soil were characterized as Pseudomonas, Alcaligenes, Bacillus, Proteus, and Enterobacter, whereas the isolates from desert soil were characterized as Alcaligenes, Bacillus, and Pseudomonas. The highest degradation rate was found to be achieved using agricultural soil. It is found that the isolated strains belonging to the genus Pseudomonas were mainly responsible for the degradation of both polymers. It has also been found that the increase of AAc ratio in the composition increases the hydrophilicity of the films and the degradation rate. PET polymer is generally found to be more resistant to the biodegradation than LDPE in the two types of soils tested. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

聚丙烯无纺布预辐射固相接枝丙烯酸的研究

以聚丙烯(PP)无纺布为基材,以丙烯酸为单体,进行预辐射固相接枝聚合,考察了外部环境、辐射剂量、温度、反应时间、单体用量、介质、阻聚剂、交联剂对接枝率的影响。结果表明,通过预辐射固相接枝聚合方法,可将丙烯酸单体接枝在PP无纺布上,辐射剂量增大可提高接枝率;反应时间对接枝率的影响在低、高温阶段有所不同。最佳反应条件为:氮气环境,辐射剂量大于50 kGy,反应温度65℃,反应时间3 h,单体浓度30%,反应介质为水,阻聚剂0.8 g,交联剂用量为5 mL。     

Radiation‐induced graft copolymerization of α‐methyl styrene and butyl acrylate mixture into polyetheretherketone films

Radiation‐induced graft copolymerization of α‐methyl styrene (AMS), butyl acrylate (BA) monomers, and their mixture was investigated on poly(etheretherketone) films. The graft polymerization was carried out using ethyl methyl ketone as the medium for the copolymerization and the maximum degree of grafting of 27% was achieved. It was observed that the grafting is significantly influenced by the reaction conditions, such as reaction time, preirrradiation dose, monomer concentration, monomer ratio, and the reaction temperature. The degree of grafting increases as the monomer concentration increases up to 30%, beyond which a decrease in the grafting was observed. The degree of grafting showed a maximum at 40% BA content in the monomer mixture. The temperature dependence of the grafting process shows decreasing grafting with the increase in the reaction temperature. The presence of AMS and BA grafts in the film was confirmed by FTIR spectra. The relative change in the PBA/PAMS fraction with respect to the reaction temperature has been found in this study. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Photo‐oxidation of cyanide in aqueous solution by the UV/H2O2 process

Photo‐oxidation of cyanide was studied in aqueous solution using a low‐pressure ultra‐violet (UV) lamp along with H₂O₂ as an oxidant. It was observed that by UV alone, cyanide degradation was slow but when H₂O₂ was used with UV, the degradation rate became faster and complete degradation occurred in 40 min. The rate of degradation increased as the lamp wattage was increased. It was also observed that cyanide oxidation is dependent on initial H₂O₂ concentration and the optimum dose of H₂O₂ was found to be 35.3 mmol dm^?3. Photo‐oxidation reactions were carried out at alkaline pH values (10–11) as at acidic pH values, cyanide ions form highly toxic HCN gas which is volatile and difficult to oxidise. By the UV/H₂O₂ process, using a 25 W low‐pressure UV lamp and at alkaline pH of 10.5 with an H₂O₂ dose of 35.3 mmol dm^?3, cyanide (100 mg dm^?3) was completely degraded in 40 min when air was bubbled through the reactor, but when pure oxygen was bubbled the time reduced to 25 min. The cyanide degradation reaction pathway has been established. It was found that cyanide was first oxidised to cyanate and later the cyanate was oxidised to carbon dioxide and nitrogen. The kinetics of cyanide oxidation were found to be pseudo‐first order and the rate constant estimated to be 9.9 × 10^?2min^?1 at 40 °C. The power required for complete degradation of 1 kg of cyanide was found to be 167 kWh (kilowatt hour). Copyright © 2004 Society of Chemical Industry     

Bio‐sorbents from cassava waste biomass and its performance in removal of Pb2+ from aqueous solution

Cassava xanthogenate and their derivatives, as adsorbents to remove Pb²⁺ from aqueous solution, are studied based upon orthogonal factorial design. The structural and thermal properties, adsorption performance as well as equilibrium‐kinetics are comprehensively investigated with multiple tools, such as Fourier transform infrared spectroscopy, thermal gravimetric analysis (TGA), and UV–visible spectrum technique. The influence of multiple parameters, including initial Pb²⁺ concentrations, compositions, pH values, and temperatures, on the adsorption performance is emphasized. The crosslinked cassava xanthogenate serves as an effective bio‐sorbent to remove Pb ions from aqueous solution, allowing regeneration in dilute acid solution. The findings in this study are beneficial for the development of adsorbents from cassava waste biomass and may contribute to environment recovery in “nature‐to‐nature” manner. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39780.     

Radiation‐induced graft polymerization of glycidyl methacrylate onto PE/PP nonwoven fabric and its modification toward enhanced amidoximation

A nonwoven fabric made of polypropylene coated by polyethylene was used as the trunk polymer in the preparation of a highly efficient new adsorbent. Metal ion uptake capacity has been aimed to be increased by introducing double amidoxime groups per repeating unit of the chains grafted to trunk polymer. The base polymer was irradiated by electron beams with a dose of 200 kGy under N₂ atmosphere and glycidyl methacrylate (GMA) was grafted onto irradiated nonwoven fabric. Grafting conditions were optimized, and GMA‐grafted polymer was modified with 3,3′‐iminodipropionitrile in ethanol at 80°C. GMA grafting (150%) was determined to be the optimum degree given that higher extent of grafting rendered the materials brittle. Pendant nitrile groups were then amidoximated by using 6% hydroxylamine in methanol–water mixture (1 : 1). The all‐polymeric structures were characterized by using FTIR, SEM, and thermal analysis methods, confirming the grafting, modification, and amidoximation stages gravimetrically, spectroscopically, and visually. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Comparative investigation of plain and silver impregnated activated carbons for the removal of cyanide from basic aqueous solutions in the batch process

Purolite AC-20 and Norit RB 0.8CC activated carbons impregnated with AgNO₃ were used for the removal of CN^– and Ag–CN complex from model wastewater. The formed Ag⁰ centers were approved by scanning electron microscopy micrographs and X-ray powder diffraction data. The degree of Ag⁰ participating in CN^– sorption varied from 100 to 45% on AC-20/Ag and from 100 to 73% on RB 0.8CC/Ag, by varying [CN^–]/[Ag] in the initial solution from 2.0 to 19.2. The Freundlich isotherm and Fleming kinetic models were consistent with the experimental data. The K_F values for the CN^– adsorption on AC-20/Ag and RB 0.8CC/Ag increased by a factor of 1.2 and 1.5, but they lowered for Ag–CN adsorption by a factor of 4.1 and 2.1, respectively, as compared to that of plain activated carbons. The removal of 90% cyanides is appropriate by combining two batches from activated carbon: impregnated, mainly for the removal of CN^–, and plain, removing the rest of Ag–CN.     

Radiation‐induced dispersion polymerization of methyl methacrylate using waterborne polyurethane as stabilizer

Waterborne polyurethane (WPU) without vinyl groups was synthesized and used as a stabilizer to prepare poly(methyl methacrylate) (PMMA) particles via dispersion polymerization with γ‐rays. The WPU molecular structure was characterized by Fourier transform infrared spectroscopy and ¹H NMR. PMMA particles were observed using scanning electron microscopy. The grafting reaction between PMMA and WPU was ascertained using ¹H NMR. Copyright © 2006 Society of Chemical Industry     

Radiation‐induced graft copolymerization of 2‐vinylpyridine and styrene onto isotactic polypropylene fiber

Isotactic polypropylene fiber (IPP) was graft‐copolymerized using 2‐vinyl pyridine (2‐VP) and styrene (sty) as the monomers by the mutual irradiation method in air. The percentage of grafting was determined as a function of various reaction parameters and it was found that the maximum grafting of 2‐VP (114%) and sty (76%) was obtained at an optimum dose of 1.08 × 10⁴ and 0.64 × 10⁴ Gy using 1.8 × 10⁻² mol of 2‐VP and 4.3 × 10⁻² mol of sty, respectively. The graft copolymers were characterized by differential scanning calorimetric analysis and isolation of the grafted chains from the grafted iPP samples. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2959–2969, 1999     

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     

Methylamino‐group‐modified hypercrosslinked polystyrene resin for the removal of phenol from aqueous solution

Chemical modification was performed for macroporous crosslinked chloromethylated polystyrene. The obtained HJ‐K01 resin was used to remove phenol from aqueous solution, and its adsorption behaviors for phenol were compared with commercial Amberlite XAD‐4. The results indicate that methylamino groups were successfully uploaded onto the surface of the HJ‐K01 resin and the adsorption capacity of phenol onto the HJ‐K01 resin was much larger than that onto XAD‐4. Furthermore, the original phenol solution was suitable for the adsorption, the adsorption isotherms could be fitted by the Freundlich model, and its kinetic curves could be characterized by a pseudo‐second‐order rate equation. The fixed‐bed column adsorption demonstrated that the HJ‐K01 resin was an excellent resin for the removal of phenol. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Gamma‐radiation‐induced graft copolymerization of acrylamide onto crosslinked poly(N‐vinylpyrrolidone)

Crosslinked poly(N‐vinylpyrrolidone) (PVPy) beads were irradiated with γ‐rays in air from a ⁶⁰Co source. Preirradiated beads were grafted with polyacrylamide by refluxing with acrylamide in water or dioxane. Conditions for optimum grafting were determined under a variety of reaction parameters, such as the total dose, duration, and temperature of heating, and the molar concentration of acrylamide used. The effect of the addition of methanol to the aqueous medium during grafting was also studied. The pendant carboxamide groups of PVPy‐g‐polyacrylamide were transformed into amino, aminoethylamido, and hydrazide functionalities terminating in primary amino or hydrazido groups. These provide sites for immobilizing proteins through their amino or carboxyl groups and, also, handles for attaching reagent molecules. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2163–2168, 1999     

Study of radiation‐induced graft copolymerization of butyl acrylate onto chitosan in acetic acid aqueous solution

The graft copolymerization of butyl acrylate onto chitosan in acetic acid aqueous solution was investigated, using the γ‐ray of ⁶⁰Co γ‐irradiation method. Fourier transform infrared spectra analysis, X‐ray diffraction analysis, and scanning electron microscopy characterized the graft copolymer. The effect of synthesis variables in the graft copolymerization have been discussed in the light of grafting efficiency, grafting percentage, and homopolymer percentage. Hydrophilicity and impact strength of the films formed from copolymer solution were tested and their feasibility as seed coating was studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2855–2860, 2003     

Gamma ray induced graft copolymerization of N-vinylpyrrolidone,acrylamide and their mixtures onto polypropylene films

The radiation initiated grafting of N-vinylpyrrolidone (NVP) acryl-amide (AAm) and their mixtures onto polypropylene (PP) films using a direct radiation technique has been investigated. Different solvents were used for diluting the monomers and it was found that dioxane was suitable for this grafting system. The influence of other grafting parameters such as inhibitor, monomer concentration and dose rate on the rate of grafting and grafting yield was studied. The values of the coefficients relating the grafting rate to monomer concentration and dose rate were found to be 1·4 and 1·5 for (NVP), and 1·6 and 1·47 for (AAm), respectively. Also, the coefficients relating grafting rate to co-monomer concentration for 20/80 and 50/50 AAm/NVP mixtures were found to be 1·6 and 1·7. Some physicochemical properties such as swelling, thermal behaviour, mechanical and electrical conductivity were also investigated, and the possibility of some practical uses, e.g. the removal of heavy metals from solution, for the grafted membranes is discussed. © 1998 SCI.     

Preparation of graphite oxide/polyurethane foam material and its removal application of malachite green from aqueous solution

Synthetic dyes are commonly used in textile, paper, leather, food, plastic and cosmetic industries. In this study, a series of novel graphite oxide/polyurethane (GO/PU) polymeric foam materials were prepared by foaming technique. The GO/PU was applied to remove malachite green (MG) from aqueous solution. When static adsorption experiment was carried out with a GO content of 3.0%, a GO/PU dosage of 40 mg/mL, a temperature of 50°C, and a time of 3 h, the highest adsorption efficiency can reach 99.7%. The kinetics, equilibrium and thermodynamics of MG adsorption onto GO/PU polymeric foam material were investigated. The results indicated that adsorption behavior was found to follow closely the pseudo‐second order kinetics, equilibrium data were well fitted by Langmuir adsorption model and the adsorption process was spontaneous and endothermic. Prepared GO/PU foam material has potential application for the wastewater treatment containing MG dye. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40988.     

Cross‐linked chitosan beads for phosphate removal from aqueous solution

Chitosan beads were cross‐linked with glutaraldehyde (GA) and epichlorohydrin (EP), respectively, at variable composition. The general features of the adsorptive and textural properties of the bead systems were characterized using p‐nitrophenolate (PNP) at pH 8.5. As well, a systematic adsorption study of phosphate dianion (phosphate ( ) species was carried out in aqueous solution at pH 8.5 and 295 K. The Sips isotherm model yielded adsorption parameters for the chitosan bead systems: (i) monolayer adsorption capacity (Q_m) for PNP ranged from 0.30 to 0.52 mmol g^?1 and (ii) Q_m values for the bead systems with ranged from 22.4–52.1 mg g^?1 for these conditions. GA cross‐linked beads reveal greater Q_m values for PNP while EP cross‐linked beads showed greater Q_m values for , in accordance with the surface chemistry and the materials design described herein. The EP cross‐linked beads show favorable adsorption–desorption properties and represents a promising tunable adsorbent system for the effective removal of phosphate dianion species in aqueous solution. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42949.     

Poly(N‐vinylpyrrolidone‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium): Synthesis,characterization, and its potential application for the removal of metal ions from aqueous solution

In the current study, poly(N‐vinylpyrrolidone‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium), poly(VP‐co‐AMPS), was prepared and used for the removal of Cu²⁺, Cd²⁺, and Ni²⁺ ions via a polymer‐enhanced ultrafiltration (PEUF) technique. The copolymer was synthesized by radical polymerization in an aqueous medium with a comonomer feed composition of 50:50 mol %. The molecular structure of the copolymer was elucidated by ATR‐FTIR and ¹H NMR spectroscopy, and the average molecular weight was obtained by GPC. The copolymer composition was determined to be 0.42 for VP and 0.58 for AMPS by ¹H NMR spectroscopy. The copolymer and homopolymers exhibited different retention properties for the metal ions. PAMPS exhibited a high retention capacity for all of the metal ions at both pH values studied. PVP exhibited selectivity for nickel ions. Poly(VP‐co‐AMPS) exhibited a lower retention capacity compared to PAMPS. However, for poly(VP‐co‐AMPS), selectivity for nickel ions was observed, and the retention of copper and cadmium ions increased compared to PVP. The homopolymer mixture containing PAMPS and PVP was inefficient for the retention of the studied metal ions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41272.