SYNTHESIS OF EPOXY(MET)ACRYLATE OLIGOESTERS AND THEIR STUDY AS A MODIFIER FOR EPOXY RESIN

The synthesis of oligoetherepoxymethacrylates has been carried out by esterifi cation of trialkyl triepoxide with methacrylic acid. The infl uence of esterifi cation conditions on the composition and yield of reaction products has been studied. It is shown that by varying the reaction conditions, the process can be directed towards preferential obtaining mono-, di- and trimethacrylic oligoesters. Synthesized oligoesterepoxymethacrylates have been used as a modifi er of epoxy resin. Self-extinguishing compositions were obtained on the basis of ED-20 epoxy resin and synthesized oligoesterepoxymethacrylates. The materials obtained by curing these compositions with amine and anhydride hardeners are characterized by improved physico-mechanical, adhesive and thermophysical properties.

Metals and metal alloys are widely used in medical devices that contact blood and/or tissue, and various coating materials for the metal parts have been proposed to improve surface properties such as biocompatibility. This study aims to understand the performance of new coating materials, copolymers of methyl acrylate and acrylic acid, in terms of their biocompatibility and adhesive strength to a metal surface. Blood compatibility was investigated through platelet and coagulation system responses. Cytocompatibility was studied in three cell-line types (endothelium, smooth muscle, and fibroblasts) in terms of cell viability and morphology; these tests showed that compatibility depended on the cell types and acrylic acid content of the copolymers. Because of their blood compatibility and adhesion strength, the methyl acrylate and acrylic acid copolymers containing 10–24 mol% acrylic acid were found to be excellent candidates as potential coating materials for devices contacting blood.

As a clean energy technology, Proton Exchange Membrane Fuel Cells (PEMFC) have been widely applied in transportation and stationary power systems. However, during fuel cell operation, impurities present in air or fuel accumulate on the electrodes, leading to poisoning of the platinum (Pt) catalyst. This poisoning reduces catalytic activity, accelerating the deterioration of fuel cell performance. These contaminants infiltrate the fuel cell system through various routes, including impurities in fuel supplies, degradation products from aging sealing materials, and organic pollutants from the ambient air.In this study, we focus on five representative organic contaminants: 1-propanol, propionic acid, acrylic acid, methyl acrylate, and benzoic acid. These substances belong to the classes of alcohols, fatty acids, unsaturated acids, esters, and aromatic acids, respectively.[1] Upon penetrating the fuel cell cathode, they strongly adsorb onto Pt active sites, hindering the oxygen reduction reaction (ORR) and causing a reduction in fuel cell voltage and efficiency. Therefore, elucidating the mechanisms by which these organic contaminants affect reactions on the Pt catalyst surface is critical for improving the contaminant tolerance of fuel cells.Initially, a three-electrode rotating disk electrode (RDE) setup was employed to systematically evaluate the impact of the aforementioned contaminants on the oxygen reduction reaction (ORR) performance of the Pt catalyst under half-cell conditions in a 0.1 M perchloric acid solution.Subsequently, varying concentrations of 1-propanol, propionic acid, acrylic acid, methyl acrylate, and benzoic acid were individually introduced into the electrolyte solution, and changes in polarization curves under each condition were monitored. Cyclic voltammetry was also performed to investigate the catalyst poisoning on the Pt surface and its recovery behavior. We found that all these contaminants significantly block the Pt surface and lead to reduced ORR activity. To understand the blocking effect of various contaminants the High-Energy Resolution Fluorescence (HERFD-XANES (Pt L₃-edge)) measurements were conducted to monitor the changes in the local electronic structure of the Pt catalyst (e.g., changes in the number of Pt 5d vacancies and oxidation states) under each contamination condition by comparing the changes in white line peak intensity. There is an obvious decrease in white line intensity due to the blocking effect of various contaminants on the Pt surface, which resembled the CV results. (Fig.1) The more strongly absorbed contaminants showed a significant decrease in white line intensity.To elucidate the adsorption behavior of contaminants on the Pt under a practical conditions various contaminants were sprayed on MEA and change in the electronic environment was recorded. We observed a significant decay in electrochemical performance and decrease in white line intensity with various contaminant. However, after 60 min’s aging at 60 °C and larger airflow, we record the XANES again, and found that electrochemical performance as well as white line intensity improved remarkably due to the removal of contaminant and approaching to the contaminant free Pt behavior for some of the contaminant which can be removed easily However the more strongly adsorbed molecules still showed a significant decay in performance and decrease in white line intensity. Acknowledgment This work is supported by the NEDO aging project commissioned by the New Energy and Industrial Technology Development Organization (NEDO)

The γ-radiation-induced crosslinking polymerization of methyl methacrylate (MMA), methacrylic acid (MAA), 2-hydroxyethyl methacrylate (HEMA), methyl acrylate (MA), and acrylic acid (AA) was carried out in bulk. The polymerization rates of AA and HEMA were much larger than those of other monomers. Acetylene had no influence on the polymerization rate in the initial stage, and the rate was dependent only on the kinds of monomers. In the absence of acetylene, gelation took place in PMA, PAA, and PHEMA obtained at complete conversion, but not in PMMA and PMAA. By the addition of acetylene, complete gelation of PMMA was observed, but no gel formation was observed for PMAA. Volume and weight swelling ratios were measured for PMA, PAA, PHEMA, and PMMA with complete gelation. It was found that by the addition of acetylene the molar concentration of crosslinks increased as much as about twice for PMA and PHEMA, and over about one hundred times for PMMA AND PAA. The relation between volume Sv and weight swelling ratio Sw was studied theoretically. Sv was expressed by the the equation, Sv = (pp /p+)Sw+ (1 -pp/ps), as a function of Sw and the densities of pure polymer (pp) and solvent (ps) in swollen polymer.

The catalytic phase transfer reactions of per acetylated alpha-D-glucosaminyl chloride with isomeric hydroxybenzoic, 1-hydroxy-2-naphthoic acids in solid potassium carbonate--acetonitrile were studied. It was found that the composition and yields of reaction products are determined by the nature of the source ofcarboxylic acids, lipophilic phase transfer catalyst, temperature. For the first time found that the O-beta-glycosyl esters of ortho-hydroxyaromatic acids in the presence of potassium carbonate can anomerizovatsya in 1,2-cis derivatives. The structure of the synthesized compounds proved 1H NMR spectroscopy. In in vivo experiments it was established that glycosyl esters of salicylic acid and per acetylated 2-carboxy phenylglucosaminide exhibit analgesic activity similar to aspirin.

The feasibility of the one- step synthesis of mixtures of Z- and E- alkenyl alkyl sulfides via the reaction of elemental sulfur with terminal and disubstituted alkynes and alkyl halides has been demonstrated in the presence of low- valent Ni, Co, Pd, and Fe complexes. The effects of structure in the starting alkynes and alkyl halides have been investigated, along with process conditions and their effect on the composition and yields of reaction products.

Chlorides of Ti(IV), V(III), Nb(V), and Mo(VI), in contrast to Cr(III) and Zr(IV) chlorides, catalyze oxidation of magnesium with cyclopentadiene to magnesium cyclopentadienide. The kinetic features of the process were revealed, and the composition and yield of reaction products were determined. Certain details of the reaction mechanism were discussed.

Relationship between properties and conversions of North Bohemian coals during coal/oil coprocessing

A series of ambient self-crosslinkable acrylic resin/protein composite emulsions (PA–Ps) were prepared by copolymerizing the functional monomer acetyl acetylethyl methacrylate (AAEM) with methyl acrylate, butyl acrylate and acrylic acid, and then protein crosslinking agents such as gelatin and casein were also added. The PA–P films were characterized by Fourier transform IR spectroscopy, contact angles, differential scanning calorimeter, thermogravimetric analysis, antisolvent testing and physicomechanical testing. Influences of AAEM and protein dosages on properties of composite films were examined in detail. The results indicate that influences of AAEM and protein on PA–P films are diverse on solvent resistance, physicomechanical properties and thermal properties. With enhancement of AAEM and protein dosages, hardness, solvent resistance to tetrahydrofuran and glass transition temperature (Tg) of PA–P films are markedly enhanced, but the decomposing temperatures (Td) are decreased. Tensile strengths are evidently reinforced while elongations at break are lessened. Suitable AAEM and protein dosages could render PA–P films with good water resistance.

Dielectric and infrared data have been obtained over a wide temperature range on copolymers of ethyl methacrylate with methacrylic and acrylic acid synthesized by radical copolymerization. The dissociation energy ΔH0 for the acid dimer in the copolymer is estimated from the temperature dependence of the relaxation strength Δεα of the α relaxation, which is associated with the glass transition. The value of δH0 obtained by this method is in fair agreement with that determined by infrared (IR) spectroscopy. The strength of the α relaxation and its activation energy are both increased by the incorporation of methacrylic acid units but are decreased by acrylic acid units. This behavior is attributed to the restriction of main‐chain motions by hydrogen‐bonded acid dimers in the copolymers with methacrylic acid and to the incorporation of more flexible links in the copolymers with acrylic acid. The β relaxation observed below the glass transition temperatures is almost unaffected by the incorporation of methacrylic acid.

Reaction of oxygen atoms with ethylene is an important step in the combustion process particularly affecting the profiles of intermediate species and flame speed. Currently, the relative importance of different pathways of this multichannel reaction at different temperatures is not fully established and determination of the branching ratios for different reaction channels as a function of temperature remains essential for modeling combustion systems. In the present work, the products of the O(3P) + C2H4 reaction have been studied over an extended temperature range (297-900 K) using a low pressure flow reactor (1-8 Torr) combined with a quadrupole mass spectrometer. The yields of the three main reaction products, H atom, CH3 radical, and CH2O, were determined to be 0.31 ± 0.05, 0.53 ± 0.09, and 0.17 ± 0.03, respectively, independent of pressure and temperature under experimental conditions of the study. For the yields of the minor reaction products, H2 and CH4, the upper limits were determined as 0.05 and 0.02, respectively. These results are compared with the experimental data and theoretical calculations available in the literature.

Reaction of oxygen atoms with propene is an important step in combustion processes particularly affecting the profiles of intermediate species and flame speed. The relative importance of different pathways of this multichannel reaction at different temperatures represents significant theoretical interest and is essential for modeling combustion systems. In the present work, we report the first experimental investigation of the products of the O(3P) + C3H6 reaction over an extended temperature range (298-905 K). By using a low pressure flow reactor combined with a quadrupole mass spectrometer, the yields of the five reaction products, H atom, CH3, C2H5, CH2O and OH were determined as a function of temperature between 298 and 905 K: 0.0064 × (T/298)2.74 exp(765/T), 1.41 × (T/298)-1.0 exp(-335/T), 0.92 × (T/298)-1.41 exp(-381/T), 0.17 × (T/298)0.165 exp(-36/T), and 0.0034 × (T/298)2.34 exp(788/T), respectively (corresponding to the variation of the respective yields between 298 and 905 K in the ranges 0.08-0.31, 0.46-0.32, 0.26-0.12, 0.15-0.19, and 0.05-011), independent of pressure in the range 1-8 Torr of helium. For the yields of the minor reaction products, H2 and CH3CHO the upper limits were determined as 0.2 and 0.05, respectively. These results are compared with the experimental data and theoretical calculations available in the literature.

Pressure-sensitive adhesives (PSAs) bond to surfaces by applying a light pressure, and must be soft and tacky which requires the glass transition temperature (T g) below −20 °C. Performance characterization is done via adhesion and cohesion. Achievement of high adhesion and high cohesion together is a challenge for PSA applications. In this study, a series of PSAs with different monomer compositions were prepared using emulsion polymerization to show the effect of polar comonomers on adhesive properties. The main monomer was butyl acrylate and methyl methacrylate, and the polar comonomer was chosen from acrylic acid (AA), methacrylic acid (MAA), acrylamide (AAm), and methacrylamide (MAAm). The adhesive performance was studied at 0.5, 1.25, and 2% of the polar comonomer content based on total monomer composition. Water-borne acrylic adhesive polymers obtained with constant thickness were coated onto a bi-oriented polypropylene and evaluated for the effect on performance by measuring their loop tack, peel, and shear strength on several surfaces, including stainless steel, glass, aluminum, and low-density polyethylene (LDPE). Results showed that MAAm increases cohesive forces compared to AAm due to dipole–dipole interactions. When the amount of polar comonomer with T g above room temperature has been decreased, there have been a significant increase on the adhesion properties and tackiness of the polymers beside on LDPE due to its non-polar surface characteristics. When AA and MAA compared, there have been a significant increase on cohesive strength on all the surfaces. The highest adhesion has been obtained using AA in a lower amount. The adhesion and cohesion balances were better achieved with 0.5% s/m MAAm and 2.5% s/m AA, respectively. This study does not only show the effect of polar monomers on adhesion and cohesion properties, but also show the adhesive and cohesive effects of hydrogen bonding on different surfaces.

ABSTRACTFrontal polymerization of deep eutectic solvents (DESs) made with acrylic or methacrylic acid as the monomer and hydrogen bond donor was studied. Fronts with acrylic acid and choline chloride propagated more uniformly than with pure acrylic acid, so an exploration into how the DES affected frontal polymerization was performed. The hydrogen bond acceptor of the DES was replaced by several analogs to determine the effect on the DES front behavior. The analogs used were talc, DMSO, lauric acid, and stearic acid, which acted as a heat sink, inert diluent, hydrogen bonding diluent, and inert phase change material, respectively. None of the methacrylic acid‐analog systems were able to sustain a front. While the acrylic acid‐analog systems did sustain a front (with the exception of stearic acid), none of the fronts replicated the acrylic acid DES behavior. The acrylic acid–talc sample behaved more violently—like pure acrylic acid polymerization—than the acrylic acid DES, and the DMSO and lauric acid samples produced slower fronts than that of the acrylic acid DES. We propose that the reactivity of the acrylic acid and methacrylic acid is enhanced in the DES. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 4046–4050

For the safe and trouble-free operation of a manufacturing plant and the safe storage of acrylic, as well as methacrylic monomers, it is important to know the polymerization stability as a function of the process parameters (temperature, oxygen concentration, and impurities, e.g., metal ions). Contamination with metal ions can be caused by the corrosion of steel units. Therefore, the influence of the metal ions Cr 3+ , Fe 3+ , Ni 2+ and Cu 2+ in the concentration range of 0-10 ppm (g/g) on the polymerization behavior and the oxygen consumption of acrylic and methacrylic acid were examined in this work. It was shown that Cr 3+ , Ni 2+ , and Cu 2+ ions extend the inhibition period of acrylic acid (AA) and methacrylic acid (MAA) and reduce the O 2 consumption. Fe 3+ ions, however, cause a decrease of the inhibition period and in the case of AA an increase of the O 2 consumption, which leads, in the end, to a faster unintentional polymerization. Therefore, alloys which contain iron should be avoided as far as possible in the construction of AA plants. Fe 3+ -ions show the opposite influence towards MAA, in this paper the presence of Fe 3+ shows a stabilizing effect.