Methyl Methacrylate-ethylene Glycol Dimethacrylate Research Articles

Metal-Organic Framework (MOF-199) Coated by Molecularly Imprinted Poly MMA-EGDMA for Solid Phase Extraction of Carbofuran from Fruit Samples

A selective adsorbent was synthesized based on the coating of a molecularly imprinted poly (methyl methacrylate-ethylene glycol dimethacrylate) (poly (MMA-EGDMA)) on the surface of metal-organic frameworks (MOFs) to obtain MMA-EGDMA@MOF-199 and used for the separation and preconcentration of carbofuran. Subsequently, carbofuran was determined by high-performance liquid chromatography with a diode array detector (HPLC-DAD). X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis were used to characterize the synthesized adsorbent. Both pH and extraction time were optimized as crucial extraction parameters. The adsorption capacity of the adsorbent was 20 mg g−1. The selectivity of the synthesized adsorbent for similar compounds was also investigated. Under the optimal conditions, the calibration curve was linear from 1.0 to 400 μg L−1. A high extraction efficiency (94%) was obtained for carbofuran with a limit of detection (LOD) of 0.4 µg L−1. The adsorbent was successfully applied to the SPE of carbofuran from fruit samples after its extraction, followed by high-performance liquid chromatography analysis.

Preparation of Black Poly(Methyl Methacrylate-Ethyleneglycol Dimethacrylate) Microspheres Using Metallic Complex Dyes

In this study, we synthesized polymethyl methacrylate cross-linked microspheres and functionalized the surface of the microspheres with amine groups, and discussed the effect of functionalization and the change of the surface morphology of the microspheres. This research uses 1:2 metal composite acid dye to dye self-synthesized microspheres with uniform particle size, and successfully prepares black polymethyl methacrylate cross-linked microspheres, which are applied to spacer microspheres.

An environmentally benign methodology to elaborating polymer nanocomposites with tunable properties using core-shell nanoparticles and cellulose nanocrystals

An environmentally benign concept based on waterborne systems is developed for preparation of novel nanocomposite materials with tunable properties. The designed nanocomposites are based on combination of core-shell latex nanoparticles, cellulose nanocrystals (CNC) and polyethylene glycol (PEG). First, core-shell latex nanoparticles from copolymer (methyl methacrylate-ethylene glycol dimethacrylate)-core and copolymer (methyl methacrylate-butyl acrylate)-shell (CS15) are prepared by starved emulsion polymerization. Likewise, incorporation of CNC aqueous suspension into the core-shell latex without any further chemical modification of the nanofiller while assuring good compatibility between both entities is achieved. PEG is effectively added to the suspension to assure multiple functions in the final material. After mixing of the ternary systems, the nanocomposites are prepared by three approaches, i.e. solution casting, solution casting followed by compression molding, and freeze drying followed by compression molding. SEM analysis shows that compression molding processes lead to the highest degree of coalescence of CS15 nanoparticles. This effect is however reduced in presence of PEG or PEG/CNC. It is further observed that the presence of PEG helps protecting CNC from thermal degradation. Thermal and thermo-mechanical analyses prove a high plasticizing performance of PEG and its good confinement between the nanoparticles and at interstitial spaces. Furthermore, it is revealed that the level of material reinforcement by CNC depends strongly on the ratio between CNC and PEG due to the establishment of strong interactions via hydrogen bonding between both components, which can affect the formation of CNC percolating network. These findings allow tuning the microstructure and related properties of the nanocomposites.

One-pot synthesis of zeolitic imidazolate framework-8/poly (methyl methacrylate-ethyleneglycol dimethacrylate) monolith coating for stir bar sorptive extraction of phytohormones from fruit samples followed by high performance liquid chromatography-ultraviolet detection

In this work, zeolitic imidazolate framework-8 (ZIF-8)/poly (methyl methacrylate-ethyleneglycol dimethacrylate) (MMA-EGDMA) composite monolith was in situ synthesized on stir bar by one-pot polymerization. Compared with the neat monolith, ZIF-8/poly(MMA-EGDMA) composite monolith has larger surface area and pore volume. It also exhibits higher extraction efficiency for target phytohormones than poly(MMA-EGDMA) monolith and commercial polyethylene glycol (PEG) coated stir bar. Based on it, a method of ZIF-8/poly(MMA-EGDMA) monolith coated stir bar sorptive extraction (SBSE)-high performance liquid chromatography-ultraviolet detection (HPLC-UV) was established for the analysis of five phytohormones in apple and pear samples. The developed method exhibited low limits of detection (0.11–0.51μg/L), wide linear range (0.5–500μg/L) and good recoveries (82.7–111%), which demonstrated good application potential of the ZIF-8/monolith coated stir bar in trace analysis of organic compounds.

Radiochemical “degelation” of polymethyl methacrylate networks

Methyl methacrylate-ethylene glycol dimethacrylate networks were synthetized and submitted to radiochemical degradation, with ageing monitored by means of sol-gel analysis. The networks were shown to undergo chain scission predominantly, which leads to their degelation, i.e., the recovery of a thermoplastic-like behavior with loss of all elastically active chains. The degelation dose was shown to increase with crosslink density and the corresponding critical conversion ratio was discussed regarding a recent and general statistical theory that covers radiochemical as well as chemical chain scissions.

Poly(methyl methacrylate-ethylene glycol dimethacrylate) copolymer for adsorptive removal of erythrosine dye from aqueous solution

AbstractThe preparation and characterization of poly(methyl methacrylate-ethylene glycol dimethacrylate), (poly(MMA-EGDMA)) polymer for erythrosine adsorption has been investigated. Erythrosine is a synthetic red dye used to color food. Water-soluble acid dyes have caused serious water pollution. Poly(MMA-EGDMA) polymer showed better adsorption performance for erythrosine at acidic region and at 30°C. The adsorption process had also been verified by Langmuir and Freundlich adsorption isotherms at 30, 40, and 50°C. Free energy of adsorption (∆G°), enthalpy (∆H°), and entropy (∆S°) changes were calculated to predict the nature of adsorption. The estimated value for ∆G° was calculated as −125.6 kJ/mol at 303 K (30°C). The estimated value for ∆H° was found as −60.69 kJ/mol at 303 K. The negative value for ∆H° indicated that the adsorption of erythrosine on poly(MMA-EGDMA) polymer was an exothermic process.

Methyl Methacrylate–Ethyleneglycol Dimethacrylate–Acrylic Acid Surface as Stationary Phase for Stir Bar Sorptive Extraction

Methyl Methacrylate–Ethyleneglycol Dimethacrylate–Acrylic Acid Surface as Stationary Phase for Stir Bar Sorptive Extraction

Kinetic Modeling of the Molecular Architecture of Cross‐Linked Copolymers Synthesized by Controlled Radical Polymerization Techniques

AbstractA recently developed general kinetic approach, based on population balances in terms of generating functions, is applied to the modeling of the molecular architecture of branched copolymers produced through controlled radical polymerization (CRP) techniques, namely nitroxide‐mediated radical polymerization (NMRP) and atom‐transfer radical polymerization (ATRP). Thanks to this method, it is possible to carry out dynamic predictions of distributions of molecular weights, sequence lengths and z‐average mean square radius of gyration of the products, both before and after gelation (whenever it occurs) with consideration of complex kinetic schemes. The model chemical systems styrene + divinylbenzene (S/DVB) and methyl methacrylate + ethylene glycol dimethacrylate (MMA/EGDMA) are experimentally investigated in order to assess the prediction capabilities of the aforementioned approach. Measurements of absolute molecular weights and z‐average radius of gyration of the copolymers are performed for different times of polymerization using a SEC system with a refractive index detector coupled with MALLS. It is shown that the proposed computational tool can enhance the possibility of better design of these complex materials but additional studies concerning the impact of intramolecular cyclizations on the structure of materials synthesized at diluted conditions are needed.

Solid-state 13C NMR spectroscopic examination of lower alcohol vapor sorption by cross-linked poly(methyl methacrylate) particles

The sensitivity and selectivity of methyl methacrylate-ethylene glycol dimethacrylate copolymers with respect to lower alcohol (methanol, ethanol, and propanol-2) vapors were examined by solid-state 13C NMR spectroscopy. A comparative analysis was carried out for the capabilities of various spectral techniques for studying sorption processes in cross-linked polymer particles.

Modeling of the Mass Transfer Effect in Biphasic Enzyme Membrane Reactor for Hydrolysis of Olive Oil

This article presents a model to explain the mass transfer phenomenon of the ions (OH-, Na+ and RCOO-) formed during the hydrolysis reaction on the aqueous side of the reaction sites in the biphasic enzyme membrane reactor (EMR) using lipase immobilized on modified poly (methyl methacrylate-ethylene glycol dimethacrylate) (PMMA-EGDM) clay composite membrane. Our model divides the aqueous side of the system into two regions, an unstirred film (aqueous side) adjacent to the pore end (region I) and charged capillaries of the membrane (region II). The process involves transport of Na+, OH- and RCOO- ions in region I whereas the film is considered as an electro-neutral region. Space charge model (consisting of Nernst-Planck equation for ion transport and nonlinear Poisson-Boltzmann (PB) equation for charge distribution) is used to describe transport of ions inside charged capillaries (pores) in region II. The solution of the nonlinear PB equation is computationally intensive and to overcome this difficulty, a series solution of the PB equation for the charge distribution inside the capillaries is developed. The suggested solution is used to determine the rate of formation of oleic acid using the information on pore size of the membrane (determined from molecular weight cut-off experiment) and diffusivity data from the literature. The result shows that the concentration of RCOO- ions at the boundary of region I of the aqueous phase increases with increasing the duration of reaction. The pore wall charge determined using the model is found to be in the range of 0.715-0.735 mV.

Monodispersed Carboxylated Composite Polymer Microspheres and Physical Immobilization of Biomolecules

Carboxylated polymer microspheres were prepared by multi steps seeded polymerization using methacrylic acid as a comonomer. Ethylene glycol dimethacrylate was used as a crosslinking agent in the second step of seeded copolymerization to provide a crosslinked network in order to limit the penetration of carboxyl group to interior of the microspheres. In this research a series of polystyrene/poly(methyl methacrylate-ethylene glycol dimethacrylate)/poly(methyl methacrylate-methacrylic acid) composite polymer microspheres with varying proportion of methacrylic acid were prepared. Carboxyl group density increased with the increase of methacrylic acid content in the recipe. Physical immobilization of some biologically active macromolecules was studied at the respective isoelectric pH value under similar conditions. The specific activities of adsorbed trypsin on different composite polymer microspheres were also measured.

Synthesis and characterization of star-like microgels by one-pot free radical polymerization

A one-pot free radical polymerization process was used to prepare methyl acrylate/ethylene glycol dimethacrylate (MA/EGDMA) and methyl methacrylate/ethylene glycol dimethacrylate (MMA/EGDMA) polymers. The role of monomer and crosslinker reactivity ratios in producing different network structures was demonstrated. While both systems produced branched polymers that exhibited low intrinsic viscosities with little variation across a wide range of molecular weights, the star-like microgels formed between a less reactive monomer (MA) with a more reactive crosslinker (EGDMA) gave lower bulk solution viscosities than the more statistical polymers formed between similarly reactive monomers and crosslinkers (MMA and EGDMA). This paper presented a simple and cost-effective synthetic route for the production of polymers with high molecular weight and low viscosity with considerable potential for industrial-scale processing.

Chromium (VI) separation from aqueous solution using anion exchange membrane

AbstractThe preparation is reported of a chemically modified crosslinked poly(methyl methacrylate–ethylene glycol dimethacrylate) (PMMA–EGDM) copolymer anion exchange ultrafiltration membrane on a macroporous clay support. This is obtained by nitrating a PMMA–EGDM membrane using NOx (a mixture of NO and NO2), which is further reduced to an amine group using hydrazine hydrate to form an anion‐exchange membrane (AEM). The membrane thus formed is characterized for its properties such as ion‐exchange capacity, membrane swelling, contact angle measurements, and membrane morphologies. The results show that the membrane becomes highly hydrophilic on the introduction of a charge and the separation experiments on the chromium (VI) salt solution show that the permeate flux (keeping the same rejection level of 90%) is considerably increased (by 100‐fold). The analysis of separation of Cr(VI) from its aqueous solution has been done by solving a two‐dimensional (in cylindrical coordinates) space‐charge model (SCM). A series solution of the nonlinear Poisson–Boltzmann equation has been generated, which leads to a considerable reduction in the computational time (from 15 h of batch time using the method reported earlier to 15 min for our method). The effective pore radius and wall potential of the unmodified and AEMs are evaluated by fitting the experimental data of the separation. The permeate flux calculated from this model matches well with the experimental values and a correlation is developed between the separation characteristic (rejection) and the wall charge developed by the chemical modification of the membrane. © 2005 American Institute of Chemical Engineers AIChE J, 2005

Enzyme membrane reactor for hydrolysis of olive oil using lipase immobilized on modified PMMA composite membrane

A non-interpenetrating crosslinked poly(methyl methacrylate-ethylene glycol dimethacrylate) (PMMA-EGDM) clay composite membrane has been prepared by using dual initiating system. We have functionalized these membranes by technique reported in literature to chemically bind the lipase on it. These are then used in biphasic enzyme membrane reactor (EMR) for hydrolysis of olive oil and the effect of various operating conditions on reaction rate was examined. The performance of the biphasic EMR is evaluated in terms of the apparent volumetric reaction rate based on the volume of the aqueous phase used for the extraction of the fatty acids. The immobilized form of the enzyme in our reactor is found to be highly stable and has been used for more than 50 h of reaction over a period of 25 days with negligible change (∼3%) in the activity. Experiment shows that the activity of lipase upon immobilization is found to increase by as much as 39%.

Preparation of NO x modified PMMA–EGDM composite membrane for the recovery of chromium (VI)

A non-interpenetrating cross-linked poly (methyl methacrylate–ethylene glycol dimethacrylate) copolymer ultrafiltration membrane on a microporous ceramic support has been prepared from the monomers in two stages. The polymer membranes thus obtained have been nitrated using NO x (a mixture of NO and NO 2) by the gas phase reaction at 80 °C. Separation experiments on the chromium (VI) salt solution have been carried out using unmodified (giving 68% rejection per pass) and nitrated membranes (giving as much as 67% rejection per pass). For nitrated membranes, the water flux and the solute flux increased with time of nitration about hundred folds because of the increase in the hydrophilicity as well as the pore size.

Modeling of high-conversion binary copolymerization

In this paper, the Three Stage Polymerization Model (TSPM) proposed in our previous publication for free radical homopolymerization was extended to describe high-conversion copolymerization reactions exhibiting a strong gel effect. Moreover, the literature data on conversion history for styrene (St)–methyl methacrylate (MMA), MMA–ethylene glycol dimethacrylate (EGDMA) and acrylonitrile (AN)-α-methylstyrene (AMS) copolymerizations were used to examine applicability of the model. It was found that TSPM is still suitable for kinetic description of the copolymerization systems mentioned above.

Effects of cyclization and electrostatic interactions on the termination rate of macroradicals in free-radical crosslinking copolymerization

Summary Effects of cyclization and ionic group contents on the termination rate of macroradicals formed at zero monomer conversion were investigated. For this purpose, the pregel regime of free-radical methyl methacrylate / ethylene glycol dimethacrylate (MMA/EGDM) and acrylamide / N,N’-methylenebisacrylamide (AAm/BAAm) copolymerization systems was studied by means of the dilatometric technique. To eliminate the chain-length dependent variation of the termination rates, different sets of experiments were carried out each at a fixed monomer and in itiator concentration. At low crosslinker contents, the termination rate of zero-conversion macroradicals was enhanced in crosslinking copolymerizations compared to linear polymerization. This is due to the cyclization reactions which reduce the size of the macroradical coils and thus, enhance the termination rates due to the lowering of the thermodynamic excluded volume effect. As the amount of the crosslinker increases, an enhancement in the in itial rate of polymerization is observed in all series of experiments, indicating that steric effects on segmental diffusion dominate at high crosslinker contents. The results also indicate a slower rate of termination of ionic macroradicals compared to the non-ionic radicals of the same molecular weight and points the significance of the thermodynamic excluded volume effect on rising the ionic group content.

Size distribution of polymers during the photoinitiated free-radical copolymerization of methyl methacrylate and ethylene glycol dimethacrylate

Photoinitiated methyl methacrylate-ethylene glycol dimethacrylate (MMA/EGDM) copolymerization has been investigated in toluene at a monomer concentration of 35 w/v %. Diphenyl-2,4,6-trimethylbenzoylphosphine oxide (DPTPO) was used as a photoinitiator at 0.3 wt% concentration. Monomer conversions and the size distribution of the polymer molecules were measured as a function of the reaction time up to the onset of macrogelation. Compared to the photoinitiators benzoin or benzoin derivatives, gelation process proceeds at much higher rates in the presence of DPTPO. The size distribution curves obtained by size-exclusion chromatography (SEC) change from monomodal to bimodal distributions as the polymerization proceeds. Strongly bimodal SEC curves were obtained in the close vicinity of the gel point. This finding confirms the coagulation type gelation mechanism of compact primary particles. It also indicates that the present gelation theories cannot describe the structure dependent kinetics of free-radical crosslinking copolymerization.

Gel formation in free‐radical crosslinking copolymerization

AbstractPolymer gels with varying amounts of crosslinker and solvent were prepared by solution free‐radical crosslinking copolymerization of methyl methacrylate/ethylene glycol dimethacrylate (MMA/EGDM) and styrene/p‐divinyl benzene (S/p‐DVB) comonomer systems. The structural characteristics of the gels were examined using equilibrium swelling in toluene and gel fraction measurements. Experimental results were compared with the predictions of a kinetic model developed recently for free‐radical crosslinking copolymerizations. Experimental data on S/EGDM networks reported by Hild, Okasha, and Rempp were also used to test this model. It was found that the model correctly predicts the development of the gel properties in free‐radical crosslinking copolymerization. © 1995 John Wiley & Sons, Inc.

Free-radical crosslinking copolymerization: Effect of cyclization on diffusion-controlled termination at low conversion

The pregelation period of free-radical methyl methacrylate/ethylene glycol dimethacrylate (MMA/EGDM) and acrylamide/ N,N′ -methylenebisacrylamide (AAm/BAAm) copolymerization systems was studied by means of the dilatometric technique. The amount of cyclization in MMA/EGDM copolymers was estimated using proton nuclear magnetic resonance and analytical titration methods. The results suggest that, in MMA/EGDM copolymerization and at a monomer concentration of 220 gl −1 , nearly half of the pendent double bonds are consumed by cyclization. It was found that the average termination rate constant of macroradicals at zero conversion, k t 0 is dependent on the crosslinker concentration. k t 0 increases first but then decreases continuously as the amount of crosslinker increases. Moreover, termination rate constants become less sensitive to conversion in the presence of small amounts of crosslinker. All of these phenomena can be explained in terms of cyclization, as it decreases the size of macroradical coils by producing intramolecular links.