Glycidyl Methacrylate for use in polymerization reactions in chemistry

Glycidyl Methacrylate for use in polymerization reactions in chemistry

New Developments and Application in Chemical Reaction Engineering

Glycidyl methacrylate (purity; 98 %) was purchased from Aldrich. Ionic liquids based on 1-n-ethy1-3-methylimidazolium (EMIm), 1-n-butyl-3-methylimidazolium (BMIm), 1-n-hexyl-3-methylimidazolium (HMIm) with different anions such as Cl- BF4- PF6- were prepared according to the procedures reported previously. Copolymerization of glycidyl methacrylate (GMA) and CO2 were carried out in a 50 mL stainless steel autoclave equipped with a magnetic stirrer. The reactor was charged with 40 mmol of GMA, 2 mmol of catalyst and then purged several times with CO2. The mixture was heated to a desired temperature. The reactor was then pressurized with CO2 at 140 psig (9.6 atm) and the reaction started. After a certain period of reaction time, the pressure was reduced to atmosphere to terminate the copolymerization. The polymer was separated by precipitation followed by filtration. The polymerization yield was determined by gravimetry.

Composite resin polymerization and relevant parameters

The BisGMA–TEGDMA system is composed of dimethacrylates. Upon curing, the resulting solid is highly cross-linked. A continuous, covalently bonded network is formed and is generally referred to a thermoset. Thermosets are not soluble or otherwise processable once cured. The advantages of a thermoset are high thermal and mechanical stability. This is in contrast to a resin composed of monomethacrylates, which would result in linear polymers that are soluble, thermally processable, and less mechanically stable. Monomers with three or four methacrylates are possible, but it is not clear if this offers a significant advantage.7,8 Details of the different methods to initiate polymerization and cross-linking will be discussed later.

Nanoarmoring of Enzymes with Carbon Nanotubes and Magnetic Nanoparticles

Chitosan, glycidyl methacrylate (GMA), bromoacetyl bromide, glutaraldehyde, triethylamine, polyvinyl alcohol (PVA; MW: 50,000), bipyridine, CuBr, and tetrahydrofuran were obtained from Sigma-Aldrich (St. Louis, USA) and used as received. All other chemicals were of analytical grade and were purchased from Merck AG (Darmstadt, Germany).

The following instruments were employed in the major characterization experiments: UV–vis spectrophotometer (AAS; AA 6800, Shimadzu, Japan), Fourier Transfer Infrared Spectroscopy (FTIR) (Perkin–Elmer Inc., Norwalk, CT, USA), Brunauer–Emmett–Teller (BET) analysis (QuantachromeNova 2200 E, USA), X-ray Diffraction (XRD) (MiniFlex 600, Rigaku), Vibrating Sample Magnetometer (VSM, model 155, Digital MeasurementSystem, Inc., Westwood, MA, USA), Scanning Electron Microscopy (SEM, ZEIZZ, Evo 50), Atomic Force Microscopy (AFM, PSIA, XE 100 E model).

2.2 Synthesis of polymer brushed magnetic nanoparticles

Fig. 1 explains an overall synthesis strategy of magnetic nanoparticles grafted with polymer brush. Fe3O4 nanoparticles were first silanized with (3-aminopropyl) triethoxysilane (APTES), functionalized with Br− ends and finally grafted with glycidyl methacrylate (GMA) brush via atom transfer radical polymerization (ATRP) initialization.

The first anion-exchange column based on a styrenic epoxide monomer

Experience with glycidyl methacrylate made us aware of the advantages of an epoxide monomer system. First, the epoxide group is considerably more reactive than a benzyl chloride moiety. The increased reactivity of the epoxy moiety dramatically broadens the range of amines that can be reacted to produce novel anion-exchange materials. Most of the most desirable tertiary amines contain hydroxyl groups substituted at the beta-carbon relative to the nitrogen. These beta-substituted hydroxyl groups substantially reduce the basicity of the tertiary amine as well as increase steric hindrance and decrease the solubility in the polymer. The combination of these three factors makes them challenging to use for the preparation of quaternary anion-exchange materials. For example, as we have learned from our experience in developing the IonPac AS5 and AS5A columns, both of which made use of a tertiary amine containing two beta-hydroxyl groups, preparing quaternary ion-exchange materials with such amines is difficult. During development of these columns, we attempted to prepare an analog with three beta-hydroxyl groups, the reason being that such materials would be even more hydroxide selective than anion-exchange sites with only two beta-hydroxyl groups. However, we were never successful in driving the reaction to completion when using vinylbenzylchloride as the reactive monomer in combination with such a tertiary amine. In contrast, the reaction product of an epoxide with a tertiary amine always produces a beta-hydroxyl group in the link between the monomer and the quaternary ion-exchange site. This means that a styrenic epoxide can introduce a third beta-hydroxyl moiety if it reacts with a tertiary amine containing only two beta-hydroxyl moieties, a much easier to accomplish reaction. Thus, the availability of a styrenic monomer with an epoxide functional group should allow for the first time the production of an even higher level of hydroxide selectivity than the previous generation of columns designed for use with hydroxide eluent.

The main problem with this idea was that, while such materials have been reported in the literature, styrenic epoxide monomers are not commercially available. As such, a member of the R&D team began work on the synthesis of two different styrene monomers containing epoxide moieties. After many months of work, we finally received approximately 10 g of monomer for experimental studies. Fortunately, we already had experience with glycidyl methacrylate as well as styrenic monomers, so we were familiar with surfactant systems suitable for emulsion polymerization of such monomer systems. Within a couple of weeks, we produced our first prototype columns using this new monomer system. Initial experiments demonstrated an exceptionally high level of hydroxide selectivity. The first column in a series of columns to use this monomer was the IonPac AS11 column. Firstly, there were several major shifts in ion-exchange selectivity associated with this new monomer. For example, peak shape was considerably better for hydrophobic anions. Secondly, anionic species with hydroxyl substituents tended to elute earlier than with the IonPac AS5A column. For example, quinic acid elutes before fluoride on the IonPac AS11 column while it elutes after fluoride on most stationary phases based on vinylbenzylchloride. The other design concept with the IonPac AS11 column was to accelerate the gradient analysis time. To accomplish this, we switched from 5-μm nonporous substrate to 13-μm nonporous substrate and increased the standard operating flow rate from 1 to 2 mL/min. As a result, while the IonPac AS5A column could separate 34 anions in less than 30 min, the IonPac AS11 column could separate the same number of anions in less than 15 min (Fig. 17). The IonPac AS11 column is still widely used today. It has the advantage of being fast and operating with a relatively low hydroxide concentration so its economical to use when using reagent free ion chromatography (RFIC). Its commonly used for screening applications when looking at unknown samples. However, it has a relatively low dynamic loading capacity and as such is not a good choice for samples containing a wide range of analyte concentrations. Several newer columns that are better choices for such samples will be discussed in following sections of this chapter.

Carbon Dioxide Utilization for Global Sustainability

A radical copolymerization of GMA (0.18 mmol) with AN (0.02 mmol) [poly(GMA-co-AN)] was prepared in dimethyl sulfoxide (DMSO, 300 mL) using 2,2’-azobisisobutyronitrile (AIBN, 0.27 g) as an initiator at 60 °C for 24 h under nitrogen atmosphere, then the solution was poured into distilled water to give a precipitate. The copolymer was recovered using an excess of methanol, and dried in vacuum at 30 °C for 12 h. The copolymer composition of poly(GMA-co-AN) was determined from the ratio of area in the copolymer using the 1Н-NMR spectrum. The ratio of area for the copolymer peak is 76.3:26.7 (GMA:AN).

The synthesis of a copolymer of DOMA and AN [poly(DOMA-co-AN)] from poly(GMA-co-AN) and CO2 was carried out using quaternary ammonium salts. 0.5 mmol of catalyst was introduced to a 250 mL four-neck semi-batch reactor containing the mixture of 5 g of poly(GMA-co-AN) and 100 mL of DMSO, and the solution was heated up to a desired temperature (100 °C). Reaction was started by stirring the solution under a slow stream of CO2 (10 mL/min), and continued for 8 h. The yield of CO2 addition to poly(GMA-co-AN) is defined as the number of unit of cyclic carbonate group in poly(DOMA-co-AN) divided by the number of unit of epoxide group in poly(GMA-co-AN).

To prepare blend films, weighed amounts of poly(DOMA-co-AN) and PEI with given composition were cast from 10 wt% solution in DMF. The films were dried under vacuum for 3 days at room temperature. Glass transition temperatures (Tg) were measured using a differential scanning calorimetry (DSC, Perkin Elmer) calibrated with pure indium as a standard.

Monolithic Materials

Macroporous poly(glycidyl methacrylate-co-ethylene dimethacrylate) (GMA–EDMA) monolithic disks were introduced in the late 1980’s, first as novel stationary phases for chromatography of biopolymers [47,48]. These] disks are promising stationary phases] for a variety of dynamic processes based on interphase mass distribution [49,50].

As with the me]mbrane absorbers, these monolithic separation media afford an enhanced accessibility of immobilized ligands located on the open surface of the flow-through channels to their specific counterparts dissolved in the mobile phase. The advantageous hydrodynamic properties of monolithic adsorbents also enable the observation of the real-time kinetics of formation of bioaffinity pairs under dynamic conditions. In other words, the mass transfer enhanced by convection allows one to consider the biospecific reaction as a process controlled only by time [50]. High performance monolithic disk chromatography (HPMDC) combines the advantages of both membrane technology (simple scale-up, low pressure-drop across a monolith, high bed stability) and column chromatography (high selectivity and efficiency of separation, high loading and capacity).

POLYMER RESINS - SYNTHESIS AND STRUCTURE

1.3 Resins containing oxirane (epoxide)16, thiirane (episulfide)17 and phenol18 functions

Epoxide containing resins based on glycidyl methacrylate (GMA) crosslinked with ethylene glycol dimethacrylate (EGDMA) are well known and have been widely exploited,19 indeed it seems that some materials are now available commercially.20 Some applications are favoured by resins with a high surface area, and to generate the latter usually requires high levels of crosslinker with a solvating porogen. This then automatically limits the maximum GMA content that can be used. We have explored the use of trimethylolpropane trimethacrylate (TRIM) as a trifunctional crosslinker to replace EGDMA, in an effort to achieve high surface areas resins with simultaneously a high GMA content.16 Table 2 summarises the resins synthesised.

33rd European Symposium on Computer Aided Process Engineering

We studied the precipitation polymerization of VCL/GMA/BIS in an aqueous solution focusing on parameter estimation approaches. We showed that incorporating quantum chemically computed parameter values and their calculation error into the estimation problem improves the optimization result. Based on the identified synthesis model, we were able to derive an improved feeding strategy of GMA to the batch reaction to achieve a homogeneous GMA composition in the microgels by testing different scenarios. Our hybrid approach of quantum chemistry and parameter estimation from experimental data shows the potential of integrating theoretical derivations and semi-empirical knowledge. Further, we laid the ground to design and optimize the functionalization of VCL-based microgels with GMA in the future.

Polymeric composite membranes and biomimetic affinity ligands for bioseparation and immunoadsorption

Immobilized-metal affinity composite-cellulose membrane for the separation of proteins

One of the key advantages of composite cellulose-GMA membrane is the abundance of epoxide groups, which provide reactive sites for the further coupling of ligands. The active group density on the matrix and the strength of the composite membranes were notably affected by the reaction conditions, such as the reaction temperature and the ratio of materials. The conditions for reaction of chelating agent (imminodiacetic acid, IDA) with the composite cellulose membrane were also optimized. A higher IDA density on the surface of the composite membrane was obtained for the reaction at 75°C, pH 11 for 4 h in the presence of 2–3% (w/v) NaCl as promoter. The relationship between flow-rate and back pressure was almost linear for a cartridge of 16 mm ID., stacked with 22 pieces of membranes. The back-pressure was only 1.17 × 105Pa when the flow rate was 14mL/min. Human serum albumin (HSA), commonly used for therapeutic purposes, must be of high purity.

Yang et al. (1998) purified commercially available HSA solution with a Ni2+-IDA membrane cartridge, and obtained the chromatogram shown in Fig. 17.14. The commercially available HSA solution and that purified on Ni2+-IDA membrane cartridge were assayed by capillary zone electrophoresis. The electropherograms are shown in Fig. 17.15. The results showed that the metal-chelating membrane provided an efficiency comparable with agarose bead based metal immobilization affinity chromatography for HSA purification, but the performance of the membrane cartridge was 3–5 times faster than agarose bead packed column. Due to its macroporous structure and the convective flow of solution through the pores, fast assay of proteins could be performed by high-performance membrane chromatography.

Monolithic Materials

Continuous 300 × 8 mm rods of porous poly (glycidyl methacrylate-co-ethylene dimethacrylate) have been prepared by free radical polymerization [71]. The epoxy groups of these monoliths were modified by a reaction with diethylamine that affords ionizable functional groups required for ion-exchange chromatography. This material was then tested for separation of proteins. A dynamic capacity of 15 mg chicken egg albumin per one  ml of the bed volume could be obtained at a flow velocity of 200 cm/min. The linear gradient elution mode enabled an excellent selectivity. However, a further scale up of monolithic columns is complicated. Therefore a modified method for the preparation of large polymethacrylate monoliths has been developed by Peters et al. [68]. In order to achieve the heat dissipation, they have used a slow polymerization procedure involving a gradual addition of the polymerization mixture into the reaction vessel. The gradual addition of the polymerization mixture resulted in very homogeneous monoliths. The pore volume in different sections of the monolith was examined and a high degree of homogeneity observed (Table 22.2). A similar approach was also tested for styrenic systems.