Polymerization Of Ethylene Glycol Dimethacrylate Research Articles

Cu(II)‐incorporated, histidine‐containing, magnetic‐metal‐complexing beads as specific sorbents for the metal chelate affinity of albumin

AbstractN‐Methacryloyl‐(L)‐histidine methyl ester (MAH) was synthesized from metharyloyl chloride and histidine. Spherical beads with an average size of 150–250 μm were obtained by the suspension polymerization of ethylene glycol dimethacrylate and MAH in an aqueous dispersion medium. Magnetic poly(ethylene glycol dimethacrylate‐co‐N‐Methacryloyl‐(L)‐histidine methyl ester) [m‐p(EGDMA‐co‐MAH)] microbeads were characterized with swelling tests, electron spin resonance, elemental analysis, and scanning electron microscopy. The specific surface area of the beads was 80.1 m2/g. m‐p(EGDMA‐co‐MAH) microbeads with a swelling ratio of 40.2% and 43.9 μmol of MAH/g were used for the adsorption of bovine serum albumin (BSA) in a batch system. The Cu(II) concentration was 4.1 μmol/g. The adsorption capacity of BSA on the Cu(II)‐incorporated beads was 19.2 mg of BSA/g. The BSA adsorption first increased with the BSA concentration and then reached a plateau, which was about 19.2 mg of BSA/g. The maximum adsorption was observed at pH 5.0, which was the isoelectric point of BSA. The BSA adsorption increased with decreasing temperature, and the maximum adsorption was achieved at 4°C. High desorption ratios (>90% of the adsorbed BSA) were achieved with 1.0M NaSCN (pH 8.0) in 30 min. The nonspecific adsorption of BSA onto the m‐p(EGDMA‐co‐MAH) beads was negligible. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2669–2677, 2004

Novel metal-chelate affinity sorbents for reversible use in catalase adsorption

A novel metal-chelate adsorbent utilizing N-methacryloyl-( l)-histidine methyl ester (MAH) as a metal-chelating ligand was prepared. MAH was synthesized by using methacryloyl chloride and l-histidine methyl ester dihydrochloride. Magnetic beads with an average size of 150–250 μm were obtained by suspension polymerization of ethylene glycol dimethacrylate (EGDMA), and MAH conducted in aqueous dispersion medium. The specific surface area of the porous beads was found to be 80.1 m 2/g. Mag-poly(EGDMA–MAH) beads were characterized by swelling tests, electron spin resonance (ESR), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). Elemental analysis of MAH for nitrogen was estimated as 43.9 μmol/g. Then, Fe 3+ ions were chelated on the magnetic beads. Fe 3+-chelated magnetic beads with a swelling ratio of 40% were used in the adsorption of catalase in batch system. The maximum catalase adsorption capacity of the mag-poly(EGDMA–MAH)–Fe 3+ beads was observed as 83.2 mg/g at pH 7.0. The K m values for immobilized catalase (mag-poly(EGDMA–MAH)–Fe 3+) (20.5 mM) were higher than that of free enzyme (16.5 mM). Storage stability was found to increase with immobilization. It was observed that enzyme could be repeatedly adsorbed and desorbed without significant loss in adsorption capacity or enzyme activity.

Chiral resolution of derivatized amino acids using uniformly sized molecularly imprinted polymers in hydro-organic mobile phases.

Uniformly sized molecularly imprinted polymers (MIPs) for Boc-L-Trp were prepared using ethylene glycol dimethacrylate (EDMA) as the cross-linker, and methacylic acid (MAA) and/or 4-vinylpyridine (4-VPY) as the functional monomers or without use of a functional monomer. The MIPs prepared were evaluated using acetonitrile or a mixture of phosphate buffer and acetonitrile as the mobile phase. The Boc-L-Trp-imprinted EDMA polymers can recognize Boc-L-Trp by its molecular shape, and can thus afford the enantioseparation of Boc-Trp. Besides the molecular shape recognition, the hydrophobic interactions with the polymer backbones as well as the hydrogen-bonding interactions of Boc-L-Trp with carboxyl and pyridyl groups in the polymers should work for the retention and recognition of Boc-L-Trp on the imprinted MAA- co-EDMA and 4-VPY- co-EDMA polymers, respectively, in the hydro-organic mobile phase. The hydrogen-bonding interactions seem to become dominant when only acetonitrile is used as the mobile phase. The Boc-L-Trp-imprinted 4-VPY- co-EDMA polymers gave the highest retentivity and enantioselectivity for Boc-Trp among the MIPs prepared. However, the simultaneous use of MAA and 4-VPY was not effective for the enantioseparation of Boc-Trp in a hydro-organic mobile phase. Furthermore, the baseline separation of Boc-Trp enantiomers was attained within 10 min on the Boc-L-Trp-imprinted 4-VPY- co-EDMA polymers under the optimized HPLC conditions.

Vibrational Overtone Activated Photo-Cross-Linking of Ethylene Glycol Dimethacrylate Using Benzoyl Peroxide and 2,2‘-(Azobis)isobutyronitrile as Initiators

Laser vibrational overtone initiated polymerization of ethylene glycol dimethacrylate (EGDMA) has been demonstrated using two initiators, benzoyl peroxide (BP) and 2,2‘-(azobis)isobutyronitrile (AIBN). Excitation of the initiator occurs through absorption of a single photon by the fifth CH stretching vibrational overtone transition at 604 nm (16 556 cm-1) for BP and 628 nm (15 924 cm-1) for AIBN. This vibrational excitation creates radicals that initiate radical chain polymerization. Monomer conversion was followed quantitatively by monitoring the intensity change of the vinyl combination band at 6169 cm-1 in the first overtone spectrum of EGDMA. Considering the concentration, the molar extinction coefficient, and laser power, AIBN was a factor of 3.2 more efficient than BP for vibrational overtone polymerization. In both cases, the rate of polymerization depends on the excitation wavelength. The influence of the initiator concentration and the photolysis duration is also presented.

N-methacryloly-(L)-histidinemethylester carrying a pseudospecific affinity sorbent for immunoglobulin-G isolation from human plasma in a column system

N-methacryloly-(L)-histidinemethylester (MAH) as a pseudospecific ligand was synthesized by using methacryloyl chloride and histidine. Spherical beads with an average size of 63-75 μm were obtained by suspension polymerization of ethylene glycol dimethacrylate (EGDMA), 2-hydroxyethyl methacrylate (HEMA) and MAH conducted in an aqueous dispersion medium. The specific surface area of the beads was found to be 18.3 m2/g. Poly(EGDMA-HEMA-MAH) beads were used in the separation of immunoglobulin-G (HIgG) from aqueous solutions and/or human plasma in a packed-bed column system. HIgG adsorption capacity of the beads decreased with an increase in the flow-rate of plasma. The maximum HIgG adsorption on the poly(EGDMA-HEMA-MAH) sorbents was observed at pH 7.4. HIgG adsorption onto the poly(EGDMA-HEMA) sorbents was negligible. Higher adsorption values (up to 135 mg/g) were obtained when the poly(EGDMA-HEMA-MAH) sorbents were used from aqueous solutions. HIgG adsorption increased with decreasing temperature and the maximum adsorption achieved at 4°C. MAH incorporation significantly affected HIgG adsorption capacity (135 mg/g). Higher amounts of HIgG were adsorbed from human plasma (up to 165 mg/g). Adsorption capacities of other blood proteins were obtained as 8.7 mg/g for fibrinogen and 14.6 mg/g for albumin. The total protein adsorption was determined as 191 mg/g. The pseudospecific affinity beads allowed one-step separation of HIgG from human plasma. HIgG molecules could be repeatedly adsorbed and desorbed with these sorbents without noticeable loss in their HIgG adsorption capacity.

Control of polymer topology through transition-metal catalysis: synthesis of hyperbranched polymers by cobalt-mediated free radical polymerization.

A novel approach was demonstrated for the synthesis of hyperbranched polymers by direct free radical polymerization of divinyl monomers controlled by a cobalt chain transfer catalyst (1). By controlling the competition between propagation and chain transfer with 1, the free radical polymerization of ethylene glycol dimethacrylate (3) afforded soluble hyperbranched polymers in one pot. The structure of the hyperbranched polymers was confirmed by (1)H and (13)C NMR. The molecular weight and intrinsic viscosity of the hyperbranched polymers were measured by matrix-assisted laser desorption ionization (MALDI) mass spectrometry and size exclusion chromatography (SEC) equipped with triple detectors. The intrinsic viscosities of the hyperbranched polymers are much lower than those of their linear analogues and do not show molecular weight dependence. The unique structure and properties of these hyperbranched polymers combined with the commercial availability of many divinyl monomers and the robustness of free radical polymerization make this new approach attractive for the preparation of new functional materials.

Determination of inorganic and organic mercury compounds by capillary gas chromatography coupled with atomic absorption spectrometry after preconcentration on dithizone-anchored poly(ethylene glycol dimethacrylate-hydroxyethylmethacrylate) microbeads

Poly(EGDMA-HEMA) microbeads were prepared by suspension polymerization of ethylene glycol dimethacrylate (EGDMA) and hydroxyethyl methacrylate (HEMA). Poly(vinyl alcohol), benzoyl peroxide and toluene were used as stabilizer, initiator, and diluent, respectively. A chelating ligand, dithizone, was then attached. The microbeads were characterized by FTIR spectrometers and elemental analysis. The affinity microbeads containing 118.9 μmol dithizone g −1 polymer were used for the adsorption/desorption of inorganic mercury [Hg], methyl mercury chloride [CH 3HgCl] and ethyl mercury chloride [C 2H 5HgCl] from aqueous media at concentrations in the range 5–1000 μg l −1 and various pH values (2.0–8.0). Adsorption rates were high, and adsorption equilibria were reached in about 30 min. The maximum adsorption of mercury species onto the dithizone-anchored microbeads from their individual solutions was 138 mg g −1 for Hg(II), 221 mg g −1 for CH 3HgCl and 207 mg g −1 for C 2H 5HgCl. The same behavior was observed during competitive adsorption in the case of the adsorption from their mixture. The affinity order of mercury species was CH 3HgCl > C 2H 5HgCl > Hg(II). Dithizone-anchored microbeads are suitable for repeated use for more than 5 cycles without noticeable loss of adsorption capacity. Speciation of organomercurials was performed using a Gas chromatography-atomic absorption spectrometry coupled system. Detection limits were increased at least 120-fold with this preconcentration approach using the dithizone-anchored microbeads.

Imprinted Membranes for Sensor Technology: Opposite Behavior of Covalently and Noncovalently Imprinted Membranes

New types of polymeric membranes with molecular recognition sites for l-phenylalanine (l-Phe), 6-amino-1-propyluracil (APU), atrazine, and sialic acid have been prepared using the molecular imprinting approach. The membrane synthesis includes radical polymerization of ethylene glycol dimethacrylate (EDMA) and functional monomers in the presence of a template. Several compounds(diethylamino)ethyl methacrylate (DEAEM), methacrylic acid (MAA), allylamine (AA), and (4-vinylphenyl)boronic acidwere as functional monomers, which are able to form covalent, ionic, or hydrogen bonds with the corresponding templates. Template specific conductometric sensors, based on these polymers, were constructed and studied. An opposite response of covalently versus noncovalently imprinted membranes was demonstrated and discussed in detail. Sensors based on these materials could detect the target molecules at concentrations of 1−50 μM in solution. The high specificity and stability of these imprinted membranes render them promis...

Photopolymerization of Di- and Tetrafunctional Methacrylic Monomers in a Polymeric Medium: Kinetics and Evidence of Reaction Diffusion Throughout the Photopolymerization Reaction

The photopolymerization behavior and reaction kinetics of ethylhexyl methacrylate (EHMA) and ethylene glycol dimethacrylate (EGDMA) monomers in styrene-butadiene-styrene block copolymer (SBS) were studied. For both monomers, di- and tetrafunctional, reaction diffusion was found to be the only mechanism of termination when the polymerization is carried out in this polymeric medium, that is, reaction diffusion controls the termination reaction from the beginning of the reaction. The polymerization of EGDMA in polystyrene and polybutadiene showed similar behavior to that in SBS. Also, the relationship between the individual rate constants k t and k p was studied, and a constant ratio of these kinetic constants was found.

Microgel formation in the free radical crosslinking polymerization of ethylene glycol dimethacrylate (EGDMA). I. Experimental

AbstractAn important feature of free radical crosslinking polymerization of ethylene glycol dimethacrylate (EGDMA) resin is the formation of heterogeneous structure through intramolecular reaction. Such structure formation affects not only the cure behavior and rheological changes of the resin but also the physical properties of the formed polymers. In this study, the reaction kinetics, morphological changes, and characteristics of formed polymers were examined by a differential scanning calorimeter, a Rheometrics Dynamic Analyzer, a dynamic light scattering goniometer, and a Fourier transfer infrared spectrometer. Experimental data showed the formation of bimodal polymers before gelation. These polymers are partially crosslinked and can be considered as microgel particles. © 1995 John Wiley & Sons, Inc.

Development of Low Density, Low Atomic Number Foam Shell with Gas Barrier for Laser Fusion Target

AbstractLow density foam shells with high optical transmittance for fuel targets for the coming upgrade laser systems were developed by increasing the polymerization initiator for trimethylolpropane trimethacrylate in an oil phase of a water/oil/water emulsion. Foam with similar performance was fabricated using reduction-oxidation polymerization of ethyleneglycol dimethacrylate. These results showed that a cryogenic fuel layer sustained by these foam layers can be charecterized using optical interference technique.

Formation and structural characteristics of porous ethylene glycol dimethacrylate networks

AbstractThe relationships between the synthesis conditions and the morphology of ethylene glycol dimethacrylate (EGDM) networks were investigated. EGDM networks were prepared by free‐radical polymerization in toluene as a diluent. The networks were characterized by swelling, porosity, and pendant vinyl group content measurements. The accessibility of pendant vinyls to low molecular weight compounds was tested using pyrrolidine as a model reactant. The results show that the polymerization of EGDM in toluene is accompanied by a phase separation in the system. The networks thus obtained are heterogeneous and exhibit an inhomogeneity in the porosity and swelling distributions. Both the weight swelling ratio and the pore volume of the networks increase with increasing monomer dilution. It was also found that the accessibility of pendant vinyls increases as the cross‐linking density of the network decreases or as its porosity increases. The results can be explained with the formation of highly cross‐linked microgels as the intermediates in the network formation processes. Two equations were derived to predict the equilibrium weight swelling ratio and the pore volume of heterogeneous networks. Satisfactory agreement of the results of measurements with the predictions of the equations was observed.

Fractography of polyethylene glycol dimethacrylate doped with polymethyl methacrylate

AbstractThe presence of polymethyl methacrylate (PMMA) can greatly affect the properties of materials made by polymerization of ethylene glycol dimethacrylate (EGDM). Fracture surfaces, examined by scanning electron microscopy, show a much wider range of morphologies in mist regions than observed in previous work on PEGDM alone. These morphologies are attributed to the moderation of brittle fracture by localized plastic deformation. It is suggested that the effect of PMMA is due to its segregation around clusters of highly cross‐linked particles of PEGDM that, as a result, become more discrete and, hence, more susceptible to interparticle displacements during fracture. In agreement With this suggestion, the mist regions usually exhibit a particulate microstructure.

Spin probe investigation of triethylene glycol dimethacrylate polymers

The temperature dependence of rotational mobility has been investigated for the spin probe 2,2,6,6-tetramethylpiperidine-1-oxyl in dense network polymers of methylene glycol dimethacrylate with varying degrees of polymerization. Irrespective of the degree of polymerization there are three characteristic regions of change in the ESR spectrum of the spin probe: high-temperature ( H = 2945–3025 A/m) and low-temperature forms (both maxima) are found. These results point to the presence of microregions, having different glass temperatures, in the structure of the polymers under investigation.

The infrared spectra and the structure of crosslinked thiethylene glycol dimethacrylate polymers

The infrared spectra and the structure of crosslinked thiethylene glycol dimethacrylate polymers

Spatial distribution of trapped radicals in .gamma.-irradiated ethylene glycol dimethacrylate polymers

Spatial distribution of trapped radicals in .gamma.-irradiated ethylene glycol dimethacrylate polymers

Polymerization of ethylene glycol dimethacrylate

AbstractIn the polymerization of ethylene glycol dimethacrylate (EDMA), the content of pendant double bonds (PDB) in the polymer was found to be lower than expected, hence it was deduced that the intramolecular cyclizations occurred in the polymerization. The experimental result that the content of PDB decreases with dilution in the solution polymerization of EDMA will qualitatively support this assumption. A composition equation in which the bimolecular linear chain growth, crosslinking, and the unimolecular cyclization are simultaneously considered, is proposed. In this equation, reactivity ratios of EDMA and PDB (r1 and r2) are used with the cyclization coefficient rc, where rc is expressed as a ratio of kc (unimolecular reaction velocity constant of intramolecular cyclization) to k11 (bimolecular reaction velocity constant of addition of EDMA to an EDMA‐type radical, which was previously derived by addition of EDMA to a radical). By the copolymerization of methyl methacrylate with PDB in EDMA‐polymers, r1 = 7.5 ± 2.5 and r2 = 1 ± 1 were experimentally determined. It has been found that the PDB contents measured in the bulk polymerization of EDMA agree with those calculated from the integrated curve of the above theoretical equation when r1 = 7.5, r2 = 1/7.5, and rc = 4.0 moles/1.