Graft Copolymerization Of 2-hydroxyethyl Methacrylate Research Articles

Emerging application of robust data envelopment analysis for optimization of graft copolymerization of poly(2-hydroxyethyl methacrylate) to Tamarindus indica seed polysaccharide

A newer application of data envelopment analysis (DEA) model with robust data envelopment analysis (RDEA) was presented for optimization of reaction variables of graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) to Tamarindus indica seed polysaccharide (TSP). It helped to find out the most appropriate reaction conditions and variables (concentrations of HEMA and reaction initiator; temperature and time duration) for copolymerization. The data generated through the experimental work has been analyzed and indexed to predict the maximum %grafting. Sensitivity analysis was performed to check robustness of efficiency scores of CCR DEA efficient samples and a comparative analysis of the CCR DEA and RRDEA efficiency score has been done. The data obtained via real-time experiments and data predicted using computational modelling predictions were found to be in close vicinity.

Optimization of the technological parameters of the graft copolymerization of 2-hydroxyethyl methacrylate with polyvinylpyrrolidone for nickel deposition from salts

Optimization of the technological parameters of the graft copolymerization of 2-hydroxyethyl methacrylate with polyvinylpyrrolidone for nickel deposition from salts

Optimization of the technological parameters of the graft copolymerization of 2-hydroxyethyl methacrylate with polyvinylpyrrolidone for nickel deposition from salts

Optimization of the technological parameters of the graft copolymerization of 2-hydroxyethyl methacrylate with polyvinylpyrrolidone for nickel deposition from salts

Graft Copolymerization of 2-Hydroxyethyl Methacrylate onto Chitosan Using Radiation Technique for Release of Diclofenac

Chitosan (CS) was modified with 2-hydroxyethyl methacrylate (HEMA) by gamma radiation to improve its water absorption ability and use it as a drug delivery system. For this, HEMA was grafted by direct method onto dissolved CS (homogeneous) or powder CS (heterogeneous) using doses less than 20 kGy. The grafting percentage was easily controlled changing the homogeneity of system. Low and medium grafting percentages (20-70%) were obtained with the heterogeneous method, while the homogeneous method yielded higher grafting percentages (~340%). CS-g-HEMA was confirmed using infrared spectroscopy (ATR-FTIR), thermogravimetric analyses (TGA) and X-ray diffraction (XRD). In addition, the swelling behaviour, critical pH, and drug absorption, using diclofenac as a model, were also evaluated. Results show that the presence of HEMA had a positive effect on swelling and the drug uptake when low grafting percentages were used; CS-g-HEMA (17%) swelled in water (261%) and loaded better amounts of diclofenac (1.5 mg g-1) than CS (0.97 mg g-1).

Radiation-induced and RAFT-mediated grafting of poly(hydroxyethyl methacrylate) (PHEMA) from cellulose surfaces

This paper presents the results of RAFT mediated free-radical graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto cellulose fibers in a “grafting-from” approach under γ-irradiation. The effects of absorbed dose and monomer concentration on the graft ratios were investigated at different monomer (HEMA) to RAFT agent (cumyl dithiobenzoate, CDB) ratios. Cellulose-g-PHEMA copolymers with various graft ratios up to 92% (w/w) have been synthesized. The synthesized copolymers were characterized by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy, elemental analysis and scanning electron microscopy. The results of various techniques confirmed the existence of PHEMA in the copolymer composition.

Chemically induced graft copolymerization of 2-hydroxyethyl methacrylate onto polyurethane surface for improving blood compatibility

To improve hydrophilicity and blood compatibility properties of polyurethane (PU) film, we chemically induced graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto the surface of polyurethane film using benzoyl peroxide as an initiator. The effects of grafting temperature, grafting time, monomer and initiator concentrations on the grafting yields were studied. The maximum grafting yield value was obtained 0.0275g/cm2 for HEMA. Characterization of the films was carried out by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements. ATR-FTIR data showed that HEMA was successfully grafted onto the PU films surface. Water contact angle measurement demonstrated the grafted films possessed a relatively hydrophilic surface. The blood compatibility of the grafted films was preliminarily evaluated by a platelet-rich plasma adhesion test and hemolysis test. The results of platelet adhesion experiment showed that polyurethane grafted polymerization with monomer of 2-hydroxyethyl methacrylate had good blood compatibility featured by the low platelet adhesion. Hemolysis rate of the PU-g-PHEMA films was dramatically decreased than the ungrafted PU films. This kind of new biomaterials grafted with HEMA monomers might have a potential usage for biomedical applications.

Controlled Release of Doxofylline from Biopolymer Based Hydrogels

In order to modify the xanthan gum (XG) polysaccharide and to develop the hydrogels meant for the drug delivery, we have prepared XG-g-poly [HEMA-co-AA] superporous hydrogel (SPH) through chemical cross-linking by graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) on to XG via redox initiator system of ammonium persulfate (APS) and N, N, N’, N’tetramethylethylenediamine (TMED), in the presence of N, N’-methylenebisacrylamide (MBA) crosslinking agent, sodium bicarbonate foaming agent, a triblock copolymer of polyoxyethylene/ polyoxypropylene/ polyoxyethylene as a foam stabilizer. Characterization of SPH was done by FT-IR, TGA, SEM, HPLC and GCMS. The prepared SPH were successfully loaded with Doxofylline (DF) drug and formulation H10 showed higher % drug content (98±2.3) and % drug entrapment efficiency (83±2.0). From the in Vitro drug release study in pH progressive media, formulation H10 showed comparatively higher release extending upto 24h.The mechanism of DF release from the SPH matrix was found to be of diffusion type.

Photo-induced synthesis, characterization and swelling behavior of poly(2-hydroxyethyl methacrylate) grafted carboxymethyl chitosan

In the present study, carboxymethyl chitosan was prepared and characterized. Photo-induced graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto carboxymethyl chitosan (CMCs) was then carried out under nitrogen atmosphere in aqueous solution using 2,2-dimethoxy-2-phenyl acetophenone (PI) as photo-initiator. Grafting process was confirmed and the produced copolymers were characterized with aid of elemental analysis, FTIR, 2D-X ray diffraction, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The effects of HEMA and PI concentrations and the reaction time on the grafting yield were investigated by determining the grafting percentage and grafting efficiency. Under the applied experimental conditions, the optimum grafting conditions were obtained at: CMCs = 0.2 g, HEMA = 0.615 mol/L, PI = 0.0078 mol/L and reaction time = 90 min. The synthesized copolymers revealed a self-ability to form physically crosslinked hydrogels. The hydrogel nature of the copolymers was investigated by studying the solubility profiles and the cyclic swelling–deswelling behavior of copolymers with different grafting extents. These investigations of the photo-synthesized graft copolymers showed that they can be tailored and exploited as promising carriers for drug delivery purposes.

Characteristics of xanthan gum-based biodegradable superporous hydrogel

A novel biopolymer-based superporous hydrogel (SPH) was synthesized through chemical crosslinking by graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) on to xanthan gum (XG) via redox initiator system of ammonium persulfate (APS) and N, N, N′, N′-tetramethylethylenediamine (TMED), in the presence of N, N′-methylenebisacrylamide (MBA) crosslinking agent, sodium bicarbonate foaming agent, a triblock copolymer of polyoxyethylene/polyoxypropylene/polyoxyethylene as a foam stabilizer. Characterization of SPH was done by FT-IR, TGA, SEM, HPC and GCMS. The effects of pH and salinity on the swelling aptitude of the SPH were investigated along with its degradability in Streptococcus bovis medium.

Synthesis and characterization of membranes obtained by graft copolymerization of 2-hydroxyethyl methacrylate and acrylic acid onto chitosan

Chitosan based membranes to be applied on wound healing as topical drug delivery systems were developed by graft copolymerization of acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) onto chitosan using cerium ammonium nitrate as chemical initiator. Evidence for graft copolymerization of the vinyl monomers onto chitosan was obtained by FTIR and DMTA. Swelling degree, cytotoxicity, thrombogenicity and haemolytic activity of these membranes were evaluated. Chitosan-graft-AA-graft-HEMA showed to be the best matrix for drug delivery systems than chitosan-graft-AA because it retains good swelling properties, but the content in HEMA has improved cytocompatibility, hemocompatibility and thrombogenic character.

Graft Copolymerization of 2-Hydroxyethyl Methacrylate (HEMA) on Persian Silk Yarn

Silk is a highly valued animal fibre that has long been used to produce textiles of the finest quality. During the degumming process it losses almost 30% of its weight. The weighting of silk fibres with mineral compounds is an effective technique to counteract this loss in weight. Chemical modification by graft copolymerization of vinyl monomers is also effective. Persian silk yarn was degummed using Marseille solution soap and graft copolymerized with 2-hydroxyethyl methacrylate (HEMA) in aqueous media by a redox initiator system. The percentage of HEMA in the feed varied from 0-100%. The grafting efficiency obtained was 70-90%. The pH of the medium varied and its effect on the graft copolymerization was investigated. The grafted silk yarn gained in weight as the pH of the copolymerization medium was reduced and the time of copolymerization increased. Grafting affects the mechanical properties of yarn by reducing the tensile strength and slightly increasing the elongation of the yarn. The solubility in a...

Radiation-induced graft copolymerization of 2-hydroxyethyl methacrylate onto chloroprene rubber membrane. II. Characterization of grafting copolymer

The cobalt-60 radiation-induced graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto a chloroprene rubber (CR) membrane has been studied in ethanol. The structure, morphology, crystallinity, thermal stability, and hydrophility of graft copolymer were characterized by means of Fourier transform infrared photoacoustic spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, differential thermal gravimetric analysis, and contact angle test methods, respectively. The permeabilities of urea, creatinine, and creatine through the CR and CR-g-HEMA membranes are investigated in a dialysis cell, and the permeation mechanism is also discussed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1745–1750, 1998

Radiation-induced graft copolymerization of 2-hydroxyethyl methacrylate onto poly(?-methyl-L-glutamate) membrane in ethanol solution

The radiation-induced graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto poly(γ-methyl-L-glutamate) membranes was investigated in ethanol. The effects of dose, dose rate, concentration of HEMA, and temperature on the degree of grafting were studied. The initial rate of grafting copolymerization shows the following functional relationship equation: dG 0 /dt = k[M] 0 D 0.56 . The average values of the apparent constants at 27 and 37°C for the initial rates of grafting are k 1 = 51 and k 2 = 91 G%h -0.44 kGy -0.56 mol -1 L, respectively. The apparent activation energy of grafting copolymerization is E = 10.7 kcal/mol.

Graft Copolymerization of 2-Hydroxyethyl Methacrylate onto Bovine Serum Albumin: Preparation and Characterization

ABSTRACT Bovine Serum Albumin (BSA) was separated from the whole blood of freshly slaughtered animals. This BSA was graft copo-lymerized with poly (2-hydroxyethyl methacrylate) and characterized. The infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and percentage of grafting of the composites were studied. The graft copolymers have better physico-chemical properties and, therefore, could be more useful in their field of application.

Radiation graft copolymerization of 2-hydroxyethyl methacrylate onto poly(γ-methyl L-glutamate) membrane. Study of regularity of graft copolymerization in aqueous solution

The regularities of radiation-induced graft copolymerization of HEMA onto PMLG membranes were investigated in aqueous system. The experimental results showed that the change of the percentage of grafting in a mixture of solvent water and ethanol appears S-shaped curve. It was found also that the radiation-induced graft copolymerization is competing with propagation, sisson, depolymerization, and crosslinking of the polymer. The influence of dose rate on rate of grafting and percentage of grafting showed that diffusion of HEMA controll the graft copolymerization. The rate of grafting is dependent not only on grafting temperature but also on HEMA concentration.

Characterization of plasma‐induced graft polymerization of 2‐hydroxyethyl methacrylate onto silicone rubber

AbstractGraft copolymerization of 2‐hydroxyethyl methacrylate (HEMA) as attempted onto the surface of silicone rubber membrane, which was pretreated by Ar‐plasma, then exposed in oxygen to introduce a peroxide group. The effect of the amount of HEMA grafted on Arplasma‐treated and graft copolymerization was examined for various parameters of power, pressure, time, reaction time, and concentration of HEMA aqueous solution. The surfaces were characterized by ATR–FTIR, ESCA, contact angle, and SEM. PHEMA was indicated by ATR–FTIR and ESCA analysis to be present successfully onto the grafted surface of silicone rubber membrane. The stable wettability, as demonstrated once the PHEMA grafted films, indicated contact with a hydrated environment by the study of contact angle. © 1994 John Wiley & Sons, Inc.

Studies on graft copolymerization of 2‐hydroxyethyl methacrylate onto poly(vinyl chloride)

AbstractPoly(vinyl chloride) was dehydrochlorinated in alkali solution and then grafted with 2‐hydroxyethyl methacrylate (HEMA) using benzoyl peroxide as a free‐radical initiator under a nitrogen atmosphere. The investigations involved examining the effects of grafting efficiency on various conditions, such as degree of dehydrochlorination, HEMA concentration, solvent effect, and reaction time. Maximum grafting to the extent of 57.2% was obtained. The mixed solvent grafting was attempted. © 1994 John Wiley & Sons, Inc.

Ultraviolet radiation‐induced graft copolymerization of 2‐hydroxyethyl methacrylate onto polypropylene

AbstractPolypropylene staple fibers were grafted with 2‐hydroxyethyl methacrylate (HEMA) using ultraviolet radiation in the presence of three different photoinitiators, uranyl nitrate (UN), ceric ammonium nitrate (CAN), and benzoin ethyl ether (BEE), separately. The parameters of grafting were optimized for obtaining maximum graft add‐on. BEE appeared to be a better photoinitiator than the other two, giving maximum possible graft add‐on. CAN, as a chemical initiator, did not show significant improvement in grafting. The moisture regain of the grafted polypropylene increased in proportion with the graft add‐on. Dyeing with reactive dye could give only light color to the grafted fiber. Possible explanations have been given. © 1994 John Wiley & Sons, Inc.

Photoinduced graft copolymerization of 2‐hydroxyethyl methacrylate on cotton cellulose in the presence of triethyleneglycol dimethacrylate

AbstractThe addition of a bifunctional monomer, triethylene glycol dimethacrylate (TEGDMA), to a grafting system containing 2‐hydroxyethyl methacrylate (HEMA) and benzoin ethyl ether photoinitiator substantially increased the graft add‐on of the unswollen and sodium hydroxide–swollen cotton cellulose. Grafting caused changes in the properties of the substrate such as moisture regain, the water of imbibition, and the dyeability with a direct and a reactive dye in accordance with the graft level. The observations have been explained in relation to structural changes in the grafted cotton. © 1994 John Wiley & Sons, Inc.

Note Kinetics of Radiation-Induced Graft Copolymerization of 2-Hydroxyethyl Methacrylate Onto Silicone Rubber Films

Note Kinetics of Radiation-Induced Graft Copolymerization of 2-Hydroxyethyl Methacrylate Onto Silicone Rubber Films