Radiation Grafting Of Acrylic Acid Research Articles

Regulation of hydrophilic performance for chlorinated polyethylene grafting acrylic acid via co-irradiation

Acrylic acid (AA) was grafted onto chlorinated polyethylene (CPE) by co-irradiation method to regulate the hydrophilic properties. The CPE samples were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and water contact angle (WCA). The WCA of CPE decreased from 108° to 60° by radiation-induced grafting AA. The CPE transformed from hydrophobicity to hydrophilicity after radiation-grafting. The wettability of the CPE improved by radiation-grafting of AA, and the hydrophilicity can be adjusted by regulating the grafting degree. It is believed that the compatibility with the matrix obviously improves for grafted CPE with the covalent bonding of AA to CPE.

A facile strategy for fabrication of HKUST-1 on a flexible polyethylene nonwoven fabric with a high MOF loading

Abstract Fabrication of metal-organic frameworks (MOFs) on polymer substrates has significant potential in the fields of adsorption, separation and catalysis. However, the loading of MOF and the stability of polymer/MOF composites require effective improvement, which remains a great challenge. In this work, a copper benzene-1,3,5-tricarboxylate MOF HKUST-1 (HK) is fabricated on a flexible polyethylene (PE) nonwoven fabric (NWF) with a high loading of 66 wt%. The synthesis of polyethylene-g-poly(acrylic acid)/HK (PE-g-PAA/HK) NWF including radiation grafting of acrylic acid (AA), adsorption of copper(II) (Cu2+) ions, and solvothermal growth process. Scanning electron microscopy images confirm that the surface of the grafted PE NWF substrate is completely covered by the HK crystals. Moreover, the loaded HK crystals present well-controlled morphology and uniform crystal size distribution. Owing to the porous structures of HK, the fabricated PE-g-PAA/HK NWF maintains a high Brunauer-Emmett-Teller (BET) surface area of 758.1 m2 g−1 and exhibits a good CO2 adsorption capacity of 2.23 mmol g−1 (101 kPa, 25 °C). The proposed radiation grafting combined activation process can be viewed as a facile strategy for fabrication of MOFs on flexible polymer substrates with a high MOF loading.

Radiation grafting of acrylic acid and N‐vinyl imidazole onto polyethylene films for lead‐ion removal: A two‐dimensional correlation infrared spectroscopy investigation

ABSTRACTTwo‐dimensional infrared (IR) correlation spectroscopy was used to follow the γ‐radiation grafting of N‐vinyl imidazole (VIm) and acrylic acid onto polyethylene films. Grafting was confirmed by the appearance of new characteristic IR bands at 1715, 1735, 1475, and 1405 cm−1, which were assigned to carboxylic groups and the stretching vibrations of aromatic CN and CN bonds, respectively. The adsorption of lead ions by the grafted polymer increased with the degree of grafting, and it showed a tendency to be altered by both the chemical structure of the matrix polymer and the steric hindrance of Pb2+ ions. The previous two factors decreased the basic chelating group activity, imposed steric constraints on the formation of complexes between the Pb2+ and VIm groups, and controlled the coordination of Pb2+ with the COO− groups. IR spectroscopy combined with two‐dimensional correlation spectroscopy provided a powerful tool for investigating the interactions between heavy metals and functional groups. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44781.

Highly hydrophilic ultra-high molecular weight polyethylene powder and film prepared by radiation grafting of acrylic acid

The surface properties of ultra-high molecular weight polyethylene (UHMWPE) are very important for its use in engineering or composites. In this work, hydrophilic UHMWPE powder and film were prepared by γ-ray pre-irradiation grafting of acrylic acid (AA) and further neutralization with sodium hydroxide solution. Variations in the chemical structure, grafting yield and hydrophilicity were investigated and compared. FT-IR and XPS analysis results showed that AA was successfully grafted onto UHMWPE powder and film; the powder was more suitable for the grafting reaction in 1wt% AA solution than the film. Given a dose of 300kGy, the grafting yield of AA was ∼5.7% for the powder but ∼0.8% for the film under identical conditions. Radiation grafting of a small amount of AA significantly improved the hydrophilicity of UHMWPE. The water contact angle of the UHMWPE-g-PAA powder with a grafting yield of AA at ∼5.7% decreased from 110.2° to 68.2°. Moreover, the grafting powder (UHMWPE-g-PAA) exhibited good dispersion ability in water.

In-situ polymerization of polyaniline in radiation functionalized polypropylene films

In-situ generation of a nanodispersed conductive polymer within a polypropylene matrix has been pursued in order to obtain flexible, conductive films. Radiation grafting of acrylic acid to polypropylene (PP) has been applied to insert carboxyl functionalities on PP. The radiation-grafted films have been further derivatized with a variety of diamines and used as substrates for in-situ chemical oxidative polymerization of polyaniline (PANI). PANI grows as a thin skin from the surface of the film as well as an interpenetrated network in its interiors. Evidence of chemical attachment of PANI to PP has been sought by performing FTIR and XPS analyses after extraction of the unbound polymer. The influence of the nature of the substituent attached to PP on the optical and electrical properties of the films has been investigated. PANI-PP skin-core films have been also tested as flexible electrodes for further electrochemical growth of the conductive polymer.

ANTIBACTERIAL PROPERTIES OF NEW BIOLOGICALLY ACTIVE SURGICAL SUTURES

Objective: to evaluate the sorption potential of various antibiotics on polylactide and polypropylene surgical threads, whose surface is modified by direct radiation grafting of acrylic acid in the presence of N, N- methylene- bis- acrylamide, and antibacterial properties and capillarity of new surgical suture. Material and methods. The surface of the surgical sutures was modified by direct radiation grafting of acrylic acid. The bond strength of different antibacterial preparations was studied with modified threads. The antibacterial activity of the threads with Levofloxacin was studied against St.aureus, E.coli, Ps.aeruginosa . The capillarity of the modified surgical suture was studied. Results. The new surgical suture has a greater affinity to the fluoroquinolone antibiotics, has a pronounced antibacterial activity against E.coli, St.aureus, Ps.aeruginosa . Conclusion. The new surgical suture material can most effectively be used in surgery for prevention of infectious complications in the postoperative period.

IR spectroscopic analysis of the structure of a biospecific sorbent based on a polyethylene matrix

We have used IR spectroscopy to study the structure of a biospecific sorbent based on a polyethylene matrix, modified by radiation grafting of acrylic acid with L-tryptophan methyl ester as the ligand. We show that grafted polyacrylic acid forms on polyethylene beads. We have established that chemical addition of the ligand to the modified polyethylene matrix occurs with participation of COOH groups of the polyacrylic acid and NH2 groups of the L-tryptophan methyl ester. We have observed that in the end product, strong hydrogen bonds are formed between the carbonyl groups of the ligand and the unreacted carboxyl groups of the grafted polyacrylic acid.

Novel comb-type hydrogels of net-[PP-g-AAc]-g-4VP synthesized by gamma radiation, with possible application on Cu 2+ immobilization

A novel comb-type grafted hydrogel system of net-[PP-g-AAc]-g-4VP was synthesized by gamma radiation in three steps. In the first step a pH sensitive graft copolymer of AAc onto PP film was obtained by radiation grafting of acrylic acid (AAc) onto polypropylene (PP) films in aqueous solution at radiation doses of 10 kGy with a 60Co source. The grafted side chains of poly (acrylic acid) (PAAc) were then cross-linked with gamma radiation at different radiation doses to give net-[PP-g-AAc]. Finally, 4-vinylpyridine (4VP) was grafted into the net-[PP-g-AAc]. The comb-type grafted hydrogel obtained, net-[PP-g-AAc]-g-4VP, has been studied through determination of graft yield and swelling behavior at room temperature. Two critical pH values were found for net-[PP-g-AAc]-g-4VP at 4.5 and 7.2. Initial studies on the immobilization of Cu 2+ ions from solution into net-[PP-g-AAc]-g-4VP films were performed. The comb-type grafted hydrogel, grafted onto PP was also characterized by differential scanning calorimetry (DSC), scanning electronic microscopy (SEM) and FTIR-ATR.

Preparation of thermosensitive membranes by radiation grafting of acrylic acid/ N-isopropyl acrylamide binary mixture on PET fabric

Thermosensitive membranes were prepared by radiation-induced graft copolymerization of monomers on PET fabrics. A binary mixture of N-isopropyl acrylamide (NIPAAm) and acrylic acid (AA) was grafted on polyester fabric as a base material to introduce thermosensitive poly( N-isopropyl acrylamide) pendant chains having LCST slightly higher than 37 °C in the membrane. The influence of ferrous sulfate, radiation dose and monomer composition on the degree of grafting was studied. The structure of the grafted fabric was characterized by thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy. The thermosensitive nature of the fabric was monitored by swelling at different temperatures. The graft copolymerization of AA with NIPAAm enhanced the LCST of the resultant membrane to ∼37 °C. The moisture vapor transmission rate (MVTR) and air permeability of the fabric decreased slightly, may be due to the slight blocking of the fabric pores. The immobilization of tetracycline hydrochloride as the model drug and its release characteristics at different temperatures were monitored.

Ampholytes from shale tar

An ampholyte with an exchange capacity of 3.9 or 7.6 mg-equiv/g for 0.1 N HCl or 0.1 N NaOH, respectively, was prepared based on a weakly basic anion exchanger from the polycondensate of shale tar by the radiation grafting of acrylic acid.

Preparation of ion exchange membranes by radiation grafting of acrylic acid on FEP films

Ion exchange membranes were prepared by radiation induced graft polymerization of acrylic acid on FEP films using preirradiation method. The influence of the ferrous sulfate and monomer concentration on the degree of grafting was investigated. Divinylbenzene, tetraethyleneglycol dimethacrylate and methylene bisacrylamide were used as crosslinkers. The membranes were characterized by FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction analysis. The swelling bahavior and specific resistivity of membranes as function of the degree of grafting and crosslink nature were evaluated. These crosslinkers had influence on the swelling and the specific resistivity of membranes depending on their chemical nature.

Preparation and properties of ion-exchange membranes prepared by the radiation-induced grafting of a styrene/acrylic acid comonomer onto low-density polyethylene

The preparation of ion-exchange membranes by the direct radiation grafting of acrylic acid and styrene onto low-density polyethylene was studied. The effects of the grafting conditions, such as the comonomer composition and concentration and the irradiation dose, on the grafting yield were also investigated. The swelling behavior, ion-exchange capacity, structural changes, and thermal properties of unsulfonated and sulfonated membranes were studied. The crystallinity decreased with grafting and sulfonation, but the chemical and thermal stability was improved by sulfonation. The removal of some toxic heavy-metal ions—Cd2+, Pb2+, and Zn2+—was studied. Some factors that influenced the metal-ion uptake were studied. The metal-ion-uptake results showed that the membranes could be used for the adsorption of the investigated metal ions and had an affinity toward Pd2+ ions in a mixture. The regeneration of the membranes was carried out by a treatment with 1M HNO3, and the membranes were used several times with high efficiency. Thus, the membranes may be suitable for pervaporation or vapor permeation to separate wastewater because of their hydrophilicity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Effect of heat and solvent treatment on radiation grafting of acrylic acid to poly(ethylene terpehthalate)

Direct radiation graft polymerization of acrylic acid onto oriented poly(ethylene terephthalate) films and fibers subjected to thermal treatment and treated with structure-active solvents, such as dichloroethane and dioxane, was studied. Based on the results of thermomechanical analysis, X-ray diffraction, sorption, and acrylic acid grafting, conclusions were drawn concerning the character of structural changes in poly(ethylene terephthalate) exposed to structure-active solvents. The physicochemical properties of the graft copolymers obtained were examined, including the resistance against γ-radiation.

Peptide immobilization onto radiation grafted PVDF-g-poly(acrylic acid) films

Introducing hydrophilic functions on poly(vinylidene fluoride) (PVDF) films surface allows the covalent immobilization of peptides. Therefore radiation grafting of acrylic acid (AA) in pre-irradiated PVDF films was achieved to allow surface functionalization with linear and cyclic peptides. Peptides were bound via spacer molecules using EDC as a coupling agent. The reactions were followed by Fourier Transform Infrared (FTIR) spectroscopy in attenuated total reflection (ATR) mode. The amount of immobilized peptides was determined by UV spectroscopy. As well, an uncommon method for PVDF characterization and reactions quantification was used: high-resolution-magic angle spinning nuclear mass spectroscopy (HR-MAS NMR). Spacer saturation of the film surface corresponded to 25mol% yield meaning that one spacer on 4 carboxylic acids was covalently bound. XPS experiments were also performed to deepen analysis of the surface composition. Peptide density is governed by steric hindrance. ELISA tests showed that the peptides’ activity is maintained.

Radiation grafting of acrylic acid onto partially deacetylated chitin for metal ion adsorbent

Radiation processing technology is proved to be a useful tool for modification of polymer material including grafting of monomer onto polymer. In this study, partially deacetylated chitin (PD-chitin) was prepared by soaking chitin in NaOH solution with various concentrations from 10% to 50% (w/w) at room temperature for four days. The degree of deacetylation (DD%) of chitin samples was measured by IR spectroscopy method. Radiation grafting of acrylic acid (AAc) onto PD-chitin was carried out by immerging PD-chitin in AAc solution (5–20%v/v) for swelling two days. The swelled PD-chitin sample was filtered and irradiated with Co-60 radiation at dose of 4.8kGy for grafting. The resulting product, so called PD-chitin-g-PAA was changed to sodium form, PD-chitin-g-PANa by treating with NaOH 1N and used as metal ion adsorbent. The adsorption capacities of studied chitin samples for metal ion typically for Cu2+ was determined using atomic absorption spectrophotometer. The results showed that the adsorption capacities for Cu2+ were as the following order: chitin<PD-chitin<PD-chitin-g-PANa<chitosan (DD76%). In addition, equilibrium isotherms were well fitted by Langmuir equation with the constants KL=15.5 and 19.4 (mg/g); b=0.02 and 0.04 (L/mg) for PD-chitin and PD-chitin-g-PANa, respectively. The obtained product, PD-chitin-g-PANa can be produced on large scale with competitive cost and used as metal ion adsorbent for water purification as well as for other purposes such as for sorption of dyes and for immobilization of bioactive substances.

Surface characterization of binary grafting of AAc/NIPAAm onto poly(tetrafluoroethylene) (PTFE)

The present study shows results on radiation grafting of acrylic acid (AAc) and N-isopropylacrylamide (NIPAAm) mixtures onto polytetrafluoroethylene (PTFE) films. The main objective is to use the modified polymer for immobilization of the avidin-streptavidin systems or other bio-compounds. Grafting onto PTFE was carried out by the pre-irradiation oxidative method in air at different dose rates and irradiation doses. The irradiation was produced with the electron beam of a 2 MV van de Graaff accelerator, and gamma-rays, from a Gamma Beam 651 PT. The samples were placed in glass ampoules with the AAc and NIPAAm mixtures, in an aqueous solution. Graft polymerization was performed by heating of the polymer–monomer composition in an argon atmosphere at temperature of 50 °C. Surface funcionalization was studied by X-ray photoelectron spectroscopy (XPS); morphology of the surface was studied by scanning electron microscopy (SEM) and hydrophylization of the surface, by contact angle measurements (static method).

Synthesis and characterization of SPE membrane based on sulfonated FEP‐g‐acrylic acid by radiation induced graft copolymerization for PEM fuel cell

AbstractA Novel solid polymer electrolyte (SPE) membrane containing both COOH and SO3H group has been prepared by simultaneous method of radiation grafting of acrylic acid onto FEP followed by sulfonation. The presence of weakly acidic acrylic acid controls the swelling in water while SO3H group provides conductivity due to its strongly ionic characteristic. FEP‐g‐acrylic acid and its sulfonated derivatives were characterized by their properties. While the mechanical properties decreased, other properties such as ion exchange capacity (IEC), water uptake and ionic conductivity increased with increase in graft content. These properties further changed on sulfonation. Acrylic acid being weakly acidic in nature, conductivity values of the grafted membrane were quite low. However, introduction of strong SO3H group resulted in conductivity closer to Nafion 117. Few sulfonated membranes have been tested with respect to H2/O2 fuel cell performance. Short‐term fuel cell test for 100 hr gave a stable performance. These membranes are less expensive compared to Nafion. Copyright © 2004 John Wiley &amp; Sons, Ltd.

Physicochemical investigation of radiation‐grafted poly(acrylic acid)‐graft‐poly(tetrafluoroethylene–ethylene) copolymer membranes and their use in metal recovery from aqueous solution

AbstractET‐g‐PAAc membranes were obtained by radiation grafting of acrylic acid onto poly(tetrafluoroethylene–ethylene) copolymer films using a mutual technique. The ion selectivity of the grafted membranes was determined toward K+, Ag+, Hg2+, Co2+, and Cu2+ in a mixed aqueous solution. The ion‐exchange capacity of the grafted membranes was measured by back titration and atomic absorption spectroscopy. The Hg2+ ion content of the membrane was more than that of either the K+ or Ag+ ions. The presence of metal ions in the membranes was studied by infrared and energy‐dispersive spectroscopy measurements. Scanning electron microscopy of the grafted and metal‐treated grafted membranes showed modification of the morphology of the surface due to the adsorption of K+ and Ag+ ions. No change was observed for the surface of the membrane that was treated with Hg2+ ions. The thermal stability of different membranes was improved more with Ag+ and Hg2+ ions than with K+ ions. It was found that the modified grafted membranes possessed good hydrophilicity, which may make them promising candidates for practical applications, such as for cation‐exchange membranes in the recovery of metals from an aqueous solution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2692–2698, 2002

Characterization and application of radiation grafted membranes in treatment of intermediate active waste

Graft copolymers that possess ionic characters were prepared by radiation grafting of acrylic acid onto polyethylene and fluorinated polymers followed by chemical treatments. Thermal stability, mechanical and ion exchange properties of the grafted and alkali-treated membranes were studied. The selectivity of the prepared membranes towards the adsorption of different metals from a simulated waste solution has been studied. The feasibility of zirconium separation from solution containing uranium was also investigated.

Membranes prepared by radiation grafting of binary monomers for adsorption of heavy metals from industrial wastes

Preparation of synthetic membranes using simultaneous radiation grafting of acrylic acid (AAc) and styrene (Sty) as individually and in binary monomer mixture onto low density polyethylene (LDPE) has been carried out. The effect of preparation conditions such as irradiation dose, monomer concentration, comonomer composition, and solvent on the grafting yield was investigated. Characterization and some properties of the prepared membranes using different analytical techniques are studied, accordingly the possibility of its practical use in industrial waste treatment is determined. The swelling behavior, electrical conductivity, thermal stability, and mechanical properties of the membranes were investigated as a function of the grafting degree. The prepared cation-exchange membranes possessed good electrical and mechanical properties, high thermal stability and possess good characteristics for separation processes. These membranes have also good affinity toward the adsorption or chelation with Fe 3+ and Pb 2+ ions either in mixture containing other metals or if exists alone in the waste solution.