Grafting Of 2-hydroxyethyl Methacrylate Research Articles

Grafting of 2-hydroxyethyl methacrylate onto polyacrylonitrile using supercritical carbon dioxide

Supercritical carbon dioxide (SCCO2) was used in this study for the surface modification of polyacrylonitrile (PAN) membrane. A two-step process was used to graft the hydrophilic monomer, 2-hydroxyethyl methacrylate (HEMA), by the free radical polymerization onto PAN. The first step was the soaking of the initiator, 2,2′-azobisisobutyronitrile (AIBN), into the SCCO2-swollen PAN. The second step involved the grafting reaction of HEMA through the pre-soaked AIBN on the surface of PAN in SCCO2. A grafting percentage up to 30 wt% was obtained under the optimal reaction temperature at 70 °C and pressure at 17.5 MPa. The modified PAN surface was coated with domains of HEMA that improved the hydrophilicity after the reaction process. The static contact angle of the polymer surface changed from the initial value of 55° to 27° after the optimal PAN surface modification process.

Influence of laser-induced for modification of polyacrylonitrile membranes by grafting of 2-hydroxyethyl methacrylate in the presence of visible light photoinitiator

Influence of laser-induced for modification of polyacrylonitrile membranes by grafting of 2-hydroxyethyl methacrylate in the presence of visible light photoinitiator

The hydrophilic modification of acrylic textile fibers by grafting of 2-hydroxyethyl methacrylate and investigation of the imparted properties

In this study, to mimic the hydrophilic character of cotton, the industrially prominent polyacrylonitrile (PAN) fibers were enriched by polar OH-groups via the graft copolymerization technique. For this purpose, the grafting of the 2-hydroxyethyl methacrylate (HEMA) was ensured in the high graft yields (∼95%). The effects of polymerization conditions such as the solvent selection, initiator type and concentration, monomer concentration, polymerization temperature, and time were investigated for the highest graft yield, where the fiber's dimensional stability is preserved. The changes in the structural, thermal, and morphological properties of PAN-g-HEMA fibers were executed by ATR-FTIR, 1H-NMR, TGA, and SEM techniques. Depending on the modified fibers' grafting yields, the changes in the tensile strength, elongation at break, moisture, and water retention properties were investigated. It was obtained that the moisture absorption of PAN fiber (2%) reached 15.7% after grafting (95% graft yield). The dyeability of the modified fibers was studied with a direct dye (Direct Black 38), which is conventionally employed for cellulose dyeing, by monitoring with the L*a*b* color measurements and K/S color strength. 0.049 g of dye was adsorbed by 1 g of PAN-g-HEMA fiber containing 68% of HEMA at pH 11 for 120 min.

Simultaneous studies on kinetics, bio-adsorption behaviour of chitosan grafted thin film nanohydrogel for removal of hazardous metal ion from water

Natural biodegradable chitosan (CS) based thin film nanogels (TNG)s were developed and optimized in order to obtain films possessing the optimal functional properties (biodegradabiity, nontoxicity and bioadhesion) to be applied for heavy metal ion removal from aqueous systems. The grafting of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) onto CS via redox initiator system of ammonium persulfate (APS) and complex catalyst CuSO4/glycine (1:1) in the presence of foaming agent sorbitol was designed. The CS-g-P(HEMA-co-AA)/nano-CaO, a novel thin film was prepared from the combination of CS-g-P (HEMA-co-AA) copolymers with the modified snail shell, nano-CaO as a nanofiller, then the so prepared CS-g-P(HEMA-co-AA)/nano-CaO nanogel thin film is used to encapsulate active toxic heavy metal ions in water systems. Characterization of TNGs was done by FT-IR, XRD, TGA, FESEM. In addition, their kinetic isotherms with proper kinetic model at optimum pH were studied. The Langmuir and the Langmuir-Freundlich adsorption isotherm models obtained by the UV spectrophotometer were applied to describe the isotherm parameter for Cr (VI) adsorption by TNG. So the TNGs are potentially suitable for use as superadsorbents exhibiting good biodegradability and are cost-effective for their better commercialization and industrialization as well.

Removing of Congo red from aqueous solution by 2-hydroxyethyl methacrylate-g-poly(ethylene terephthalate) fibers

Grafting of 2-hydroxyethyl methacrylate (HEMA) on poly(ethylene terephthalate) (PET) fibers was carried out via free-radical polymerization technique using benzoyl peroxide as initiator. The obtained copolymers were examined by scanning electron microscope and Fourier-transform infrared spectroscopy analysis, and it was proved that HEMA was successfully grafted onto the PET structure. The synthesized fibrous adsorbents were used to remove Congo red (CR) from aqueous solutions by batch adsorption method. The effects of pH, grafting yield, operation time and dye concentration were studied to find optimal conditions for adsorption of CR by the HEMA-grafted PET (PET-g-HEMA). The obtained results showed that the amounts of adsorbed dye on the PET-g-HEMA lowered with increasing pH. At pH 2, the dye amount adsorbed by the fibers increased with increasing dye concentration up to 70 ppm and grafting yield up to 110%. It was also seen that the adsorption had considerably rapid kinetic and achieved equilibrium within 60 min. The maximum removing abilities of the grafted fibers was found to be 16 mg/g when the beginning concentration of CR was 70 ppm at pH 2. The dye was desorbed from the loaded fibers with 1 M NaOH solution, and it was found that 83% of the adsorbed dye was recovered. The investigations on reusability of the PET-g-HEMA fibers showed that the constructed fibers can be used at least five times without losing adsorption capacities for CR. All these results indicate that the grafting can be used to remove the anionic dyes from the aqueous solution.

Two-step grafting of 2-hydroxyethyl methacrylate (HEMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) onto a polyethylene plate for enhancement of Cr(VI) ion adsorption

ABSTRACTPolyethylene (PE) plates grafted with a neutral monomer, 2-hydroxyethyl methacrylate (HEMA), and a cationic monomer, 2-(dimethylamino)ethyl methacrylate (DMAEMA), (PE-g-PHEMA)-g-PDMAEMA plates were prepared by the two-step photografting. The Cr(VI) ion adsorption behavior of the (PE-g-PHEMA)-g-PDMAEMA plates was investigated as a function of the amounts of grafted HEMA, amount of grafted DMAEMA, initial pH value, and temperature. The adsorption capacity of the DMAEMA-grafted PE (PE-g-PDMAEMA) and (PE-g-PHEMA)-g-PDMAEMA plates had the maximum value at the initial pH value of 3.0, independent of the temperature. The adsorption capacity of (PE-g-PHEMA)-g-PDMAEMA plates increased with the amount of grafted HEMA (GHEMA) in the first-step grafting. The increase in the water absorptivity of the grafted layers and thereby the increase in the degree of protonation of dimethylamino groups on grafted PDMAEMA chains were found to lead to the increase in the adsorption capacity. This adsorption capacity was higher than or comparable to those of other polymeric adsorbents for Cr(VI) ions. The Cr(VI) ion adsorption behavior on both PE-g-DMAEMA and (PE-g-PHEMA)-g-PDMAEMA plates obeyed the mechanism of the pseudo-second-order kinetic model and was well expressed by Langmuir isotherm. The high values of the Langmuir constant suggest that the adsorption of Cr(VI) ions occurs through an electrostatic interaction between protonated dimethylamino groups on grafted PDMAEMA chains and ions. Cr(VI) ions were successfully desorbed from PE-g-PDMAEMA and (PE-g-PHEMA)-g-PDMAEMA plates in eluents such as NaCl, NaCl containing NaOH, NH4Cl, NH4Cl containing NaOH, and NaOH.

Kaolinite-polymer compounds by grafting of 2-hydroxyethyl methacrylate and 3-(trimethoxysilyl)propyl methacrylate

Novel kaolinite-polymer solids containing methacrylate groups were prepared by functionalization of the Brazilian São Simão kaolinite with the monomers 2-hydroxyethyl methacrylate (HEMA) and 3-(trimethoxysilyl)propyl methacrylate (TMSPM). Functionalization involved reflux of the monomers in the presence of kaolinite previously intercalated with dimethylsulfoxide (DMSO). HEMA and TMSPM effectively displaced DMSO molecules from the clay mineral interlayer, forming AlOC bonds in organic-inorganic hybrid matrices. The resulting materials were characterized by powder X-ray diffraction, thermal analysis, infrared spectroscopy and TEM analysis. Powder X-ray diffraction evidenced the intercalation of DMSO, and its substitution by HEMA and TMSPM. Thermal analyses indicated that HEMA- and TMSPM-functionalized kaolinite materials were thermally stable up to 300°C. The shift of the infrared bands due to interlayer hydroxyl groups and the presence of bands due to characteristic vibrations of the methacrylate groups (3349, 3331, 3290, and 1589cm−1) also confirmed the functionalization of the kaolinite with the monomers. The ability of both monomers to graft methacrylate groups onto kaolinite interlayer space was also analyzed. The solids obtained were used as adsorbents of dye methylene blue (MB), showing that the clay nanocomposites could remove the dye more efficiently than the isolated precursors (pure kaolinite and the polymers) separately. The kinetics of the process followed a pseudo-second order model and equilibrium fitted well to the Freundlich model.

Enhancing the hydrophilicity of polypropylene microporous membranes by the grafting of 2-hydroxyethyl methacrylate via a synergistic effect of photoinitiators

Membrane surfaces modified with polymers based on 2-hydroxyethyl methacrylate (HEMA) is promising for hydrophilicity, biocompatibility, and functionality. In this work, the UV-induced graft polymerization of HEMA onto polypropylene microporous membrane (PPMM) was studied using ferric chloride (FeCl 3) and benzophenone (BP) as co-photoinitiators with different methods for the first time. It was found that the conventional photoinitiator, BP, could not initiate the grafting polymerization of HEMA on the PPMM. Incorporation of FeCl 3 into the reaction system remarkably enhanced the grafting of HEMA onto PPMM, which could be ascribed to the “synergistic effect” between Fe 3+ and BP. Results indicated that the maximum grafting degree for the soak method, which added monomer, photoinitiators and membranes in acetone/water mixture together was 2.5-fold greater than that for the adsorption method. Therefore, the grafting degree of HEMA on the membrane surface could be modulated in a wide range through the variation of UV irradiation time, monomer concentration, and BP/FeCl 3 ratio. The poly(HEMA)-modified membrane surfaces were characterized by attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Static water contact angle of the membrane surface indicated a decrease from 145° to 42° with the grafting degree increasing from 0 to 35.67 wt.%. Water drop lied on the modified surface with 35.67 wt.% of grafting degree permeated completely into the membrane pores in 3 s. Furthermore, these poly(HEMA)-tethered membranes showed well protein resistance and potential hemocompatibility due to the enhancement of surface hydrophilicity.

New LDPE Copolymeric Films with Enhanced Hydrophilic Properties Prepared by Gamma Irradiation

Graft copolymerization induced by gamma radiation has being used as a tool to modify the surface properties of a range of polymeric substrates. This work describes the use of this technique for the grafting of 2-hydroxyethyl methacrylate (HEMA) branches onto low-density polyethylene (LDPE) surface, in order to improve its hydrophilic properties. Sample preparation protocols were selected from previous work in order to obtain films with high grafting yields. The obtained PE-g-HEMA films were characterized by thermal analysis techniques (DSC and TGA), and by Fourier transform infrared spectroscopy (FTIR). The results obtained show that, upon irradiation, there is some loss of cristalinity of the copolymer backbone, but also that the samples keep a good thermal stability. The water uptake of the samples was evaluated. Hydration levels up to near 95 % with a ydration/dehydration average ratio of 1:5 were obtained.

Radiation Grafting of 2-Hydroxy Ethyl Methacrylate (HEMA)/Glycidyl Methacrylate (GMA) onto Polyethylene-Coated Polypropylene Non-woven Fabric

The paper presents results of an investigation of the possibility of applying polyethylene-coated polypropylene (PE-co-PP) nonwoven fabric for treating dye wastes resulting from wastewater of the textile industry. For this purpose the radiation-induced graft copolymerization of binary mixtures of 2-hydroxy ethyl methacrylate (HEMA)/glycidyl methacrylate (GMA) onto polyethylene-coated polypropylene by the pre-irradiation method has been investigated. The effect of different factors that may affect the grafting percent such as solvent type and comonomer compositions were studied. Two solvents, dimethyl sulphoxide (DMSO) and 1-butanol were used. It was found that the degree of grafting depend upon the type of solvent and the composition of the comonomer mixture. Morphology of grafted nonwoven fabric was examined by scanning electron microscope (SEM). The hydrophilic properties in terms of swelling percent and water uptake were investigated. The higher swelling and water uptake percent were achieved at 100% HEMA diluted with 1-butanol. The use of these modified samples as absorbents for different classes of dyestuffs normally released from textile factories was achieved. The results obtained showed that the highest percentage of dye sorption was found in the case of basic dye and the lowest one in the case of reactive dye, depending on the reactive groups on the dye. Copolymers with a higher proportion of HEMA monomer diluted with 1-butanol as solvent showed the highest hydrophilic properties and higher dye uptake.

Modification of LDPE molecular structure by gamma irradiation for bioapplications

The surface properties of low-density polyethylene (LDPE) can be modified by the grafting of 2-hydroxyethyl methacrylate (HEMA). This was done aiming at the production of new materials suitable for bioapplications. Samples with different monomer concentrations were prepared from LDPE particles by gamma irradiation, following different irradiation protocols, including irradiation in presence and absence of air. The samples were characterized by thermal analysis techniques (DSC and TGA) and by Fourier transform infrared spectroscopy (FTIR). The results obtained show a decrease in the crystallinity of the supporting matrix for copolymers with high yields of grafting. However, the new materials prepared maintain good structural order resulting from the protective effect of polyHEMA grafted onto LDPE backbone. These effects can improve the diffusion of other species deeper inside the matrix and increase the material hydrophilicity. The studies performed made possible the selection of experimental protocols adequate for the production of new copolymeric materials with high grafting yield. These were used in the production of new LDPE films with enhanced hydrophilic properties.

Grafting of 2-Hydroxyethyl Methacrylate onto Isotactic Poly(propylene) Using Supercritical CO2 as a Solvent and Swelling Agent

Grafting of 2-hydroxyethyl methacrylate (2-HEMA) onto isotactic polypropylene (iPP) was carried out by free-radical polymerization using supercritical carbon dioxide (SC CO2) as a solvent and swelling agent. The iPP film was first impregnated with the monomer 2-HEMA and initiator benzoyl peroxide (BPO) with SC CO2 at 308.15 K. After releasing CO2 , the 2-HEMA molecules in the film were grafted onto the iPP at a higher reaction temperature. By this method, the grafting level and the morphology can be controlled by soaking time, pressure, concentrations of 2-HEMA and BPO, reaction temperature, and reaction time. The products were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). Contact angle measurements of 2-HEMA grafted iPP film using water as the test liquid showed a significant improvement of the surface polarity. The polymer films, having a markedly bumpy texture, were obtained under suitable conditions.

Kinetics of radiation-induced grafting of 2-hydroxyethyl methacrylate onto chloroprene rubber membrane and computer verification

Kinetics of radiation-induced grafting of 2-hydroxyethyl methacrylate onto chloroprene rubber membrane and computer verification

Kinetics of radiation‐induced grafting of 2‐hydroxyethyl methacrylate onto chloroprene rubber membrane and computer verification

Grafting of 2-hydroxyethyl methacrylate(HEMA) onto chloroprene rubber(CR) membrane was carried out in ethanol by direct cobalt-60 gamma ray irradiation. The kinetics of the grafting reaction was studied in respect of concentration of monomer, dose rate and temperature. The experimental results show that the functional relationship equation is dg0/dt = k[M]1.5 Ḋ. The apparent activation energy and collision frequency factor of the grafting polymerization are 46.2 kJ mol−1 and 4.98 × 107 mg cm−2 kGy−1 mol−1.5 litre1.5, respectively. The work established the relationship of the initial grafting rate (dg0/dt) with various effect factors: ln (dg0 dt) = 17.7 − 5560(1/T) + 1.5 ln [M] + ln Ḋ. This equation is also verified for the first time by a software named SMR, which function is using multiple linear regression to calculate the regression coefficient of a linear equation. © 1999 Society of Chemical Industry

Grafting of 2‐HEMA on IPP and in situ chlorinated PP through solution polymerization

Grafting of 2-hydroxyethyl methacrylate (2-HEMA) on isotactic polypropylene (IPP) and in situ chlorinated polypropylene (CPP) by free radical process was carried out at 110°C using toluene as solvent. Various conditions for grafting were optimized. The maximum percent of grafting of 2-HEMA achieved on IPP was 3.6%, whereas that on in situ CPP was 8.7%. The products were characterized by Fourier transform infrared spectroscopy and thermal and contact angle measurements. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 69: 2107–2113, 1998

Grafting of 2-HEMA on IPP andin situ chlorinated PP through solution polymerization

Grafting of 2-hydroxyethyl methacrylate (2-HEMA) on isotactic polypropylene (IPP) and in situ chlorinated polypropylene (CPP) by free radical process was carried out at 110°C using toluene as solvent. Various conditions for grafting were optimized. The maximum percent of grafting of 2-HEMA achieved on IPP was 3.6%, whereas that on in situ CPP was 8.7%. The products were characterized by Fourier transform infrared spectroscopy and thermal and contact angle measurements. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 69: 2107–2113, 1998

Low density polyethylene with an isocyanate functional group

In order to introduce an isocyanate (NCO) functional group into low density polyethylene (LDPE), grafting of 2-hydroxyethyl methacrylate (HEMA) combined with isophorone diisocyanate (IPDI) on to LDPE was carried out in solution using a radical initiator. The spectra of infrared (i.r.) and proton nuclear magnetic resonance for HEMA combined with IPDI showed that the hydroxyl group of HEMA and the NCO group of IPDI were reacted to form urethane, and the secondary NCO group preferentially reacted over the primary NCO group. From the i.r. spectra of the grafted LDPE, it was found that NCO groups were introduced into LDPE. Thermal stability of the grafted LDPE was investigated by differential scanning calorimeter analysis, and rheological values were observed to evaluate processability.

Development and characterization of a wettable surface modified aromatic polyethersulphone using glow discharge induced HEMA-graft polymerisation.

The aromatic polyethersulphone (PES) is a well known polymer for the preparation of membranes with excellent thermal stability and chemical resistance. The disadvantage of PES-membranes is their hydrophobic character, which in contact with protein containing solutions leads to high protein adsorption and as a consequence to deterioration of membrane properties. In this report the surface modification of PES by means of glow discharge induced grafting of 2-hydroxyethyl methacrylate (HEMA) is described. Graft polymerisation creates a largely wettable layer of poly(2-hydroxyethyl methacrylate) (PHEMA) on the surface of PES. This has been shown by contact angle measurements using the Wilhelmy plate method. Chemical characterization is carried out by means of X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy/attentuated total reflection (FTIR-ATR). The influence of storage conditions on the surface properties of modified PES samples has been investigated after storage in vacuum, water, and air.

Studies on the radiation‐induced graft copolymerization of mixtures of n‐butyl acrylate and 2‐hydroxyethyl methacrylate on polyurethane. I. Synthesis and characterization

AbstractModification of polyurethane, by grafting two types of monomers, a hydrophilic and hydrophobic, with an aim to enrich the surface with both hydrophobic and hydrophilic moieties, is attempted. Grafting of 2‐hydroxyethyl methacrylate and n‐butyl acrylate from a mixture of these two onto polyurethane by γ‐irradiation and subsequent characterization of the graft copolymer by infrared spectroscopic method, mechanical characterization, contact angle, and scanning electron microscopy is detailed.

Note Radiation-Induced Grafting of 2-Hydroxyethyl Methacrylate Onto Silk for Biomedical Applications

Etude de l'influence de la composition du solvant, de la dose d'irradiation et de son debit, et de la concentration du monomere sur le pourcentage de greffage