Surface modification of macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins for improved Candida antarctica lipase B immobilization

Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0 m²/g), specific volumes (from 0.755 to 1.191 cm³/g) and particle sizes (<100 μm–630 μm) were synthesized via suspension polymerization. Modifications of poly(GMA-co-EGDMA) with various diamines (1,2-diaminoethane, 1,4-diaminobutane, 1,6-diaminohexane and 1,8-diaminooctane), 2-fluoroethylamine, glutaraldehyde and cyanuric chloride were carried out. The influence of the interaction between Candida antarctica lipase B (Cal-B) and various carriers during immobilization on the loading and hydrolytic activity (hydrolysis of para-nitrophenyl acetate) of the immobilized Cal-B were studied. Immobilization of Cal-B was performed at different temperatures and pH values. Cal-B immobilized at 30 °C and pH 6.8 was leading to increased activities. Purely physical adsorption between enzyme and copolymer was observed on carriers in which amine or fluorine groups were introduced into the carrier structure by modification with various diamines or 2-fluoroethylamine. As a consequence enzyme loading and activity decreases. In contrary, modification of the poly(GMA-co-EGDMA) with glutaraldehyde and cyanuric chloride results in a covalent connection between enzyme and carrier. The obtained results show a significant increase in Cal-B activity. The influence of the amount of glutaraldehyde and cyanuric chloride used for modification was screened. Increasing the amount of glutaraldehyde or cyanuric chloride used for modification resulted in an increase of the enzyme loading. Consequently, higher amount of glutaraldehyde used led to a higher fraction of the enzyme molecules that are covalently connected on to the carrier. As the amount of glutaraldehyde or cyanuric chloride used for modifications increases, activity of immobilized C. antarctica lipase B primarily increases, showing the highest value for 0.66% and 0.050% w/w, respectively, and subsequently decreases. We could show that Cal-B immobilized on epoxy-containing copolymer modified with glutaraldehyde and cyanuric chloride performs higher activity than free enzyme powder.     

Particulate poly(glycidyl methacrylate-co-ethylene dimethacrylate) material for protein separation by anion-exchange chromatography

New materials with different structures are being developed in order to be used in protein separation by ion exchange chromatography. Materials for beds are becoming of smaller particulate size, at the expense of lower permeability, in order to obtain better peak resolution during separation. On the other hand, polymeric organic monoliths, obtained by “in situ” polymerization, have been synthethized in recent years for similar purposes. In this work, a variety of poly(glycidyl methacrylate-co-ethylene dimethacrylate) resin has been synthetised by “in situ” polymerization, milled and classified in order to verify its behaviour when used at particulate state in protein separation by ion exchange chromatography, even at semipreparative scale, which is not possible to carry out using monoliths. The particulate and classified material was aminofunctionalized with diethylamine and then properly characterized in order to determine its physical properties and evaluate its separation performances once packed in chromatographic columns. The results show that the material obtained presents good permeability and favourable equilibrium isotherms. Kinetics follows the pore diffusion model, giving diffusion coefficients similar to others reported for several commercial materials. The axial dispersion coefficients obtained at different flow rate allow to forecast a reasonably good behavior in the anion exchange chromatographic fractionation of proteins, as it was proved with egg white proteins at laboratory and semipreparative scale.     

Reactive polymers,XXXVII. An investigation of the internal structure of polymeric sorbents based on poly(2,3-epoxypropyl methacrylate-co-ethylene dimethacrylate)

The internal structure of polymeric sorbents based on 2,3-epoxypropyl methacrylateethylene dimethacrylate was investigated by means of mercury porosimetry and by employing the sorption method. The results were confronted with characteristic chromatographic data and helped to elucidate the relationships existing between the internal structure of copolymers and their chromatographic properties.     

Immobilization of DNA on poly(glycidyl methacrylate-co-ethylene dimethacrylate), bead cellulose and sepharose

Summary The copolymer of glycidylmethacrylate with ethylene-dimethacrylate, its derivatives, bead cellulose and Sepharose were used for immobilization of DNA via new coupling methods: reaction with oxirane, acylhydrazide hydrazide, and diazonium salt. The susceptibility of immobilized DNA for DNAse was tested. The most efficient immobilization was achieved on carriers with acylhydrazide groups. The binding capacity of the carrier and the susceptibility of immobilized DNA for the DNase depends on the length of the spacer. The immobilized DNA is stable in solution for several weeks, and in the lyophilized state for several months.     

Reactive polymers. 60. glycidyl methacrylate-styrene-ethylene dimethacrylate terpolymers modified with strong-acid groups

Glycidyl methacrylate-styrene-ethylene glycol dimethacrylate (GMA-ST-EDMA) terpolymers were prepared by suspension radical polymerization. The polymer is enriched in styrene during the polymerization, and this can be explained by kinetic and thermodynamic factors operating simultaneously. The terpolymers were used in the preparation of strong-acid ion exchangers. Special attention was paid to the stability of ion exchange derivatives under the conditions of ion exchange. The GMA-EDMA copolymer, which according to its IR spectra contained sulfonate groups, was the most stable: its exchange capacity did not decrease even after one hundred exchange cycles. Modified GMA-ST-EDMA terpolymers undergo an autocatalytic hydrolysis of the polymeric matrix, which gradually dissolves.     

A hydrophilic matrix for boron isolation: Monodisperse-porous poly(glycidyl methacrylate-co-ethylene dimethacrylate) particles carrying diol functionality

The novel chelating adsorbent has been synthesized by functionalization of monodisperse-porous poly(glycidyl methacrylate-co-ethylene dimethacrylate) particles with N-methylglucamine (NMDG) as a boron selective ligand. The resulting resin can adsorb boron in almost all pH range (pH 4–10) and its maximum capacity is ca. 12 mg/g. The adsorption behavior of poly(GMA-co-EDM)NMDG resin obeyed Langmuir isotherm well.     

Immobilization of mushroom polyphenol oxidase on poly(allyl glycidyl ether-co-ethylene glycol dimethacrylate) macroporous beaded copolymers

Functional, macroporous, beaded copolymers containing epoxy groups were synthesized for immobilization of polyphenol oxidase (PPO) from edible mushroom (Agaricus bisporus). The effect of incorporation of two different sets of monomers such as glycidyl methacrylate (GMA) and allyl glycidyl ether (AGE) and the effect of cross-linking agent ethylene glycol dimethacrylate (EGDM) with varying cross-link densities on binding and expression of mushroom PPO activity were studied. The effect of porogen viz. cyclohexanol and hexanol on PPO immobilization was studied. AGE copolymers with hexanol as a porogen were found to give higher binding and expression of PPO activity than GE polymers. Cross-linking of amino groups of enzyme with 5% glutaraldehyde for 6 h gave a stable binding of PPO on AGE-75(Hex) polymer with storage half-life of approximately 25 days. Under optimum conditions, AGE-75(Hex) polymer gave 70.3% of activity yield while percent retention of PPO activity was found to be 83.5%. Immobilized PPO showed a broader pH, higher temperature and excellent storage stability.     

Reactive polymers. XXXII. Effect of composition of polymerization feed on morphology and some physical properties of macroporous suspension copolymers glycidyl methacrylate–ethylene dimethacrylate

The effects of inert solvent concentration of crosslinking agent and initiator and polymerization temperature on specific surface area, porosity, penetration modulus, stress at break, and inner and surface morphology of the copolymer glycidyl methacrylate–ethylene dimethacrylate were investigated. There is a direct influence of interfacial tension between the continuous and dispersed phases in suspension at the beginning of polymerization on the morphology of the bead, and hence on the resulting physical characteristics of the structure.     

Reactive polymers,XXXVIII. Sorption of acid gases on macroporous 2,3-epoxypropyl methacrylate copolymers modified by a reaction with amines

Macroporous copolymers of 2,3-epoxypropyl methacrylate and ethylenedimethacrylate modified by aminolysis yielded sorbents with various contents of amino and hydroxy groups. The dependences of structural characteristics of these sorbents and of the sorption of sulphur dioxide on the content of crosslinking agent and on the cyclohexanol/dodecanol ratio used as the porogenic medium in the preparation of copolymers were investigated. The sorption of sulphur dioxide depends on the geometrical structure of the sorbent, concentration, chemical structure and accessibility of functional groups.     

Reactive polymers. XXVI. Sorption properties of the glycidylmethacrylate-ethylenedimethacrylate copolymer modified with ammonia

Sorption properties of the glycidylmethacrylate-ethylenedimethacrylate copolymer with the ? OH and ? NH₂ groups were characterized by using the static and dynamical procedure. Hg(II) was found to be sorbed selectively from the acetate buffer. Using sorption and desorption isoplanes determined in the measurements, conditions of the sorption of Hg(II) and its separation from an excess of some metal ions (Cu(II), Pb(II), Cd(II), Co(II), Zn(II), Ca(II), Mg(II)) were determined.     

Selective adsorption of bilirubin by macroporous poly(glycidyl methacrylate-co-divinylbenzene) beads

Macroporous glycidyl methacrylate (GMA)-divinylbenzene (DVB) copolymer beads have been synthesized and the adsorption of bilirubin, albumin and other serum components were studied. The beads composed of DVB/GMA in the weight ratio of 75/25 provide an excellent bilirubin adsorption ability. When the surface of the beads was previously coated with albumin, discriminating adsorption of the bilirubin in the serum was attained and the adsorption of albumin was depressed. In addition, when the coated albumin was crosslinked with glutaraldehyde, the excellent bilirubin adsorption ability was maintained, however, an adsorption of albumin from the serum occurred.     

Monodisperse macroporous poly(glycidyl methacrylate) microspheres coated with silica: Design,preparation and characterization

Monosized macroporous poly(glycidyl methacrylate) (PGMA) microspheres that were 9.3 μm in size were synthesized by multistep swelling polymerization using a modified Ugelstad technique. The PGMA microspheres and their hydrolyzed analogs derived from poly(2,3-dihydroxypropyl methacrylate) (PDHPMA) were coated by silanization with tetraethoxysilane (TEOS) and (3-aminopropyl)triethoxysilane (APTES), respectively. The particles were characterized by elemental and thermogravimetric (TGA) analysis, scanning and transmission electron microscopy (SEM and TEM) coupled with an energy dispersive X-ray analysis (EDAX) and FT-IR spectroscopy to determine the SiO₂ content, morphology, particle size, polydispersity and structure. These types of particles are expected to have improved biocompatibility relative to their starting polymers.     

Reactive polymers. XX. The preparation of a carrier with aldehyde groups by oxidation of a macroporous glycidyl methacrylate-ethylenedimethacrylate copolymer with periodic acid

The oxidation of a macroporous glycidyl methacrylate-ethylenedimethacrylate copolymer and of a polymer formed by its hydrolysis was investigated at temperatures ranging from 5 to 80°C with various concentrations of periodic acid. The reaction yields (formylmethyl)-methacrylate units bearing free aldehyde groups capable of further reactions. The results allowed to estimate the activation energy of the reaction (60 and 27.5 kJ mol^-1) and to discuss its mechanism. The oxidation of the epoxide group seems to proceed in two steps with vicinal glycol as the intermediate product.     

Reactive polymers, 51. The temperature behaviour of macroporous methacrylate sorbents

The behaviour of macroporous methacrylate copolymers was investigated in the temperature range between 20 and 270°C. On the basis of retention of methyl alcohol and n-decane a discontinuity at 40°C was recorded in all cases, interpreted by the increasing mobility of chains of surface layers of the polymer globules. This temperature agrees with the reported T_g value of poly(glycidyl methacrylate) and is independent of further substitution of the polymer chain with ionogenic groups. At 210–250°C depolymerization takes place; in the case of methacrylic acid copolymers cyclic anhydrides are formed, while in the case of esters alkyls are eliminated. Modified copolymers of 2,3-dihydroxypropyl methacrylate with ionogenic groups are more stable thermally — the depolymerization proceeds under the same conditions to a smaller degree. Heating is connected with changes in the morphology of particles and pores, and also in the polarity of the polymers noticeable by the ratio of retentions of alcohols and paraffins and by the heat of dissolution.     

Fabrication of ZIF-8@super-macroporous poly(glycidyl methacrylate) microspheres

ZIF-8@super-macroporous poly(glycidyl methacrylate) (SM-PGMA) microspheres were synthesized. The SM-PGMA microsphere was a novel material with high surface areas and large pore size. Here, ZIF-8 was loaded effectively both on the surface and inside of the macro-pores of microspheres by a facile way. The ZIF-8@SM-PGMA microspheres were characterized by SEM, TEM, XRD and FTIR. Additionally, they were used as an adsorbent material for the adsorption of phenol from aqueous solutions. The results indicated that the ZIF-8@SM-PGMA microspheres possessed apparently higher adsorption capacity for phenol than that of SM-PGMA microspheres. The ZIF-8@SM-PGMA microspheres obtained in this study have great potential for adsorption, separation, catalysis etc.     

Chemical transformations of polymers,XXI. Imidazole containing polymers from crosslinked macroporous poly(methacrylic acid esters) with reactive sulfoester groups

New imidazole containing polymers were synthesized by nucleophilic substitution reactions of poly(ethylene methacrylate arylsulfonates) with imidazole, benzimidazole and some of their derivatives. The reaction time and the solvents used had varying effects on the binding rates. The conversion was best reproducible at high reaction speed in ethanol.     

Chromatographic properties of macroporous beads from poly(GMA-co-EDMA)

A series of macroporous glycidyl methacrylate-ethylene dimethacrylate copolymers have been prepared by the suspension polymerization according to a statistical design of experimental approach in which concentration of ethylene dimethacrylate and time needed for raising the polymerization temperature from 20 to 70°C have been varied. The porous properties of hydrolyzed copolymers have been characterized by means of size exclusion chromatography using polystyrene standards in tetrahydrofuran. Pore volume, specific surface area, and pore size are affected by the crosslinking agent concentration rather than by the rate of temperature increase during the polymerization reaction.     

Macroporous membranes. 3. Properties of macroporous membranes synthesized from glycidyl methacrylate,ethylene dimethacrylate and alkyl- or hydroxyalkyl methacrylate

A series of macroporous membrances composed either of glycidyl methacrylate and ethylene dimethacrylate with an addition of other monomer chosen from a group comprising 2-hydroxyethyl methacrylate, butyl methacrylate, octyl methacrylate or dodecyl methacrylate, or of a copolymer of 2-hydroxyethyl methacrylate and ethylene dimethacrylate were synthesized and their properties were determined. The addition of a third monomer changes the porous properties only when the concentration of the monomer in the polymerization feed is rather high. The presence of bulkier alkyl side chains in a polymer matrix raises hydrophobicity and reduces the water regain while the strength of the membrane increases.     

Textural properties of poly(glycidyl methacrylate): acid-modified bentonite nanocomposites

The aim of this study was to obtain enhanced textural properties of macroporous crosslinked copolymer poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) by synthesizing nanocomposites with acid-modified bentonite. Nanocomposites were obtained by introducing various amounts of acid-modified bentonite (B_A) into the reaction system. All samples were characterized by attenuated total reflectance infrared spectroscopy, scanning electron microscopy, transmission electron microscopy (TEM), mercury intrusion porosimetry, and low temperature physisorption of nitrogen. The FTIR and TEM analysis confirmed incorporation of B_A into the copolymer structure and the successful formation of nanocomposites. TEM images confirmed formation of nanocomposites having both intercalated and exfoliated acid-modified bentonite in copolymer matrix. A significant increase of specific surface area, pore volume, and porosity of the nanocomposites in comparison to the copolymer were obtained. The difference between textural properties of nanocomposites with different amounts of incorporated acid-modified bentonite was less prominent.