Acrylic Content Research Articles

Preparation of acrylate-modified cationic flocculant by polymer reaction and its performance in treating oilfield-produced water

Introducing a lipophilic group into a cationic polymer flocculant can effectively improve the flocculation performance for treating oilfield-produced water. Copolymerization of acrylate and cationic monomers is the most commonly used method; however, the acrylate content in the copolymer is limited by its solubility in water. In this study, a polymer reaction method was proposed to introduce a suitable acrylate into a cationic polymer to improve flocculation performance. Acrylate was introduced into the copolymer (PDD) of methacryloyloxyethyltrimethylammonium chloride (DMC) and diallylamine (DAA) via the reaction between acrylate and the secondary amine in PDD. The effects of the acrylate type, amount of acrylate introduced, and reaction conditions on the flocculation performance of the product were investigated. The experimental results showed that the hydroxy-terminated acrylate-modified PDD exhibited considerably better performance than PDD, especially the hydroxyethyl acrylate (HEA)-modified PDD (PDD-HEA). When the dosage was 20 mg/L, the oil removal of PDD-HEA was 95.8 %, which was 1.5 times higher than that of PDD. The introduction of HEA can improve the ability of PDD to aggregate oil droplets, but it causes curling of the PDD molecular chain and weakens its bridging and flocculation ability. Therefore, a higher amount of HEA introduced does not necessarily lead to a better performance of the PDD-HEA. The most suitable modification degree of the structural units in PDD was 3.3 %. This study provides new insights into the synthesis and properties of hydrophobically modified cationic polymer flocculants and is helpful for the development of flocculants for oilfield-produced water treatment.

Preparation and Properties of Novel Modified Waterborne Polyurethane Acrylate

A series of novel modified waterborne polyurethane acrylate (WPU-EA) emulsions were prepared with isophorone diisocyanate (IPDI), polycarbonate diol, 2,2-bis-hydroxymethyl-propionic acid (DMPA), 1,4-butanediol (BDO), epoxy acrylate (EA), and pentaerythritol triacrylate (PETA). The structure of WPU-EA was confirmed by FTIR and 1H NMR spectroscopy. The effects of different dosages of epoxy acrylate on the cured film were investigated by tensile properties, dynamic mechanical analysis and thermogravimetric analysis. The results indicate that with increasing content of epoxy acrylate, the average particle size of the emulsion gradually increases. With the rise in epoxy acrylate concentration from 0%, 3.0%, 6.0% to 9.0%, the gel fraction of the cured film increases from 83.7%, 92.5%, 93.0% to 93.6%, respectively, and the glass transition temperature rises from 90.3 °C, 107.5 °C, 141.9 °C to 146.6 °C. The tensile strength and the thermal stability of the cured film increases, and the elongation at break decreases. Moreover, the WPU-EA emulsions were sprayed on polycarbonate sheets and exhibited the advantages of high hardness, better gloss and good adhesion, which is promising for the application of plastic coatings.

Designing Photothermal Superhydrophobic PET Fabrics via In Situ Polymerization and 1,4-Conjugation Addition Reaction.

This study demonstrates a simple and fast method to integrate superhydrophobicity, UV protection, and photothermal effect onto PET fabrics. The surface of PET fabric forms a hierarchical rough structure through in situ oxidative polymerization of the pyrrole (Py). The 1,4-conjugate addition reaction between pentaerythritol tetraacrylate, 3-aminopropyltriethoxysilane, and octadecyl acrylate not only endows the PET fabric with superhydrophobicity but also forms a cross-linked network structure which improves the stability of multifunctional coatings on the surface of the PET fabric. In addition, the wettability of the prepared PET fabric is investigated by adjusting the Py monomer and octadecyl acrylate concentration. The results reveal that the prepared PET fabrics exhibit obviously superhydrophobic behavior with a contact angle of 155.8°. The surface temperature of the superhydrophobic PPy/PET fabric can rise to 91 °C under a simulated sunlight which is much higher than the pristine PET fabric, while reaching basically the same steady-state in five heating/cooling cycles. The prepared PET fabric also possesses excellent self-cleaning, UV shielding, and solar light absorption performances. Furthermore, the superhydrophobic PET fabric exhibited excellent stability against 180 °C high temperature, strong UV radiation, different pH solutions and organic solvent erosion, 8 h washing tests, and 25 sandpaper abrasion cycles. These findings provide a path for the future development of multifunctional fabrics using fluorine-free environmentally friendly materials.

Influence of various factors on surface properties of elastomeric materials based on nitrile butadiene rubbers

Objectives. The influence of the technological additive content and accelerated aging conditions on the surface energy and elastic-strength properties of nitrile butadiene rubbers with an average acrylic acid nitrile content and rubbers based on them were studied in the paper.Methods. The free surface energy of the samples was determined under the standard conditions and in the accelerated aging conditions with the use of the Owens, Wendt, Rabel, and Kaelble method.Results. It was shown that the elastomeric materials surface energy is influenced by surfactants such as rosin and stearic acid, which are typical ingredients of rubber compounds. It was also found that the thermal aging effect on the physical and mechanical properties of rubbers based on nitrile butadiene rubbers depends on the method of rubber isolation from latex and on the nature of the surfactant components in the samples.Conclusions. The analysis of the results obtained shows that the change in the vulcanizates physical and mechanical properties, depending on the technological additive content and the temperature effect, occurs along with a change in the critical surface tension.

Modeling the wetting of titanium dioxide and steel substrate in water-borne paint and varnish materials in the presence of surfactants

This paper reports the results of studying the effect of two additives such as polyether siloxane (PS) and sodium polyacrylate (SPA) on the wetting of various substrates in water-borne paints (WB paints). Titanium dioxide (TiO2), paraffin (PA), steel (ST), and glass (GL) were used as solid substrates. The edge wetting angle (θ0) and the ratio (dCosθ/dСS) were used as the criterion for assessing the wettability of solid substrates. In aqueous solutions (without acrylic resin), both surfactants improve the wetting of the substrates. For PS, all the substrates studied, depending on θ depression, can be arranged in a row: ST>PA>GL>TiO2. For SPA: PA>TiO2>GL>ST. The introduction of an acrylic film-forming agent in the composition enhances the wetting ability of SPA (in comparison with the aqueous solution of surfactants). With an increase in the concentration of SPA from 0 to 4 g/dm3 in acrylic resin solutions, the edge wetting angle of steel decreases by 6÷8° (while in water by only 3°). With respect to TiO2, the wetting activity of SPA does not depend on the acrylic content of the water. PS in acrylic-containing compositions exhibits worse wetting activity than SPA. The introduction of surfactants in the compositions improves the quality of coatings. With optimal SPA contents in the compositions, the corrosion rate of coatings is reduced (in distilled water by 45 %, in 60 % NaCl solution by 60 %). At the same time, the gloss of coatings increases by 50 % while adhesion increases by 2 points (according to ISO 11845: 2020). This is fully correlated with the nature of the effect of surfactants on the wetting of the steel substrate and pigment (titanium dioxide). Based on probabilistic-deterministic planning, the compositions of WB paints were optimized, ensuring their maximum wetting of TiO2 and ST. Equations for calculating cosθ depending on the content of acrylic polymer and surfactants have been derived

Lipophilic monomer tackifying hydrogel antifouling coatings prepared by soap free emulsion polymerization and its performance

Lipophilic monomer tackifying hydrogel with good adhesion ability on organic substrates prepared in oily systems contain a large number of volatile organic compounds(VOCs). In this study, lipophilic monomer tackifying hydrogel prepolymers were fabricated in an aqueous system by soap-free emulsion polymerization to solve the above problems. The effects of reaction temperature, monomer type and comonomer ratio on soap-free emulsion polymerization were investigated. The structure of the hydrogel antifouling material was characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The adhesion properties of the lipophilic monomer tackifying hydrogel antifouling material on the organic substrate were investigated by a “static seawater immersion panel experiment” and “dynamic rotating seawater experiment”. The antifouling ability of the lipophilic monomer tackifying hydrogel was investigated by inhibiting the adhesion of microalgae and bovine serum albumin (BSA) and panels tests in a real marine environment. The results showed that the lipophilic monomer tackifying hydrogel antifouling material with good adhesion on an organic substrate was successfully prepared by soap-free emulsion polymerization. When the molar content of butyl acrylate was 30%, it did not fall off after 28 days of the dynamic rotating experiment. The change in water absorption caused by the acrylic acid content has a direct impact on protein adhesion. Panels in the real marine environment experiments displayed that the lipophilic monomer tackifying hydrogel had considerable inhibitory ability on biological attachment.

Improving the digital to garment inkjet printing properties of cotton by control the butyl acrylate content of the surface treatment agent

Direct to garment inkjet printing (DGIP) is an eco-friendly textile dyeing method that utilizes a simple process with a small amount of ink for textile products. In general, water-based pigment ink is printed on the surface of cotton; however, due to the high hydrophilicity of cotton's surface, the ink is absorbed excessively, which causes ink smearing, low color strength, and unstable wet rubbing fastness characteristics. In this study, the surface treatment agent (STA) for DGIP, which improved the color strength, wet-rubbing fastness of cotton, and STA dispersion stability characteristics, was enhanced by controlling the butyl-acrylate (BA, soft segment) and the vinyl-acetate (VA, rigid segment) ratios. The wet-rubbing fastness improved as the BA ratio increased though the color strength and ink sharpness properties deteriorated. The total K/S color strength of the surface-treated cotton using the BA30 condition was improved by 30% wet rubbing fastness class 3–4 than neat cotton, and the ink smearing phenomenon was verified to decrease. Ultimately, an optimal STA condition was established by adjusting the ratio of BA and VA wt% where the DGIP characteristics of printed cotton verified that these were the simplest parameters to adjust for optimal impact.

A critical evaluation of novel demulsifying agents based on acrylic terpolymers for Mexican heavy crude oils dehydration

• Random acrylic terpolymers as demulsifying agents for crude oil. • Trifunctional molecule with exceptional dehydrating and clarifying capacities. • Higher performance to dehydrate crude oils than commercial formulations. • Prediction of dehydrating efficiency as function of the crude oil properties. A novel kind of random acrylic terpolymers based on butyl acrylate (B), 2-(dimethylamino)ethyl acrylate (Ae), and 2-carboxyethyl acrylate (Ce) monomers was obtained by emulsion polymerization. Monomers’ weight ratios were varied, keeping in all cases a higher content of butyl acrylate (60, 70, 80, and 90 wt%) and controlling the number average molecular mass ( M ¯ n ) during polymerization. The random acrylic terpolymers were characterized by spectroscopic techniques; subsequently evaluated as demulsifier agents in three aged heavy crude oils of 7.55, 6.11, and 3.33 °API (apparent gravities), which form very stable water-in-oil (W/O) emulsions. The best performance for removing the emulsified water at 80 °C was obtained with terpolymers containing 90–80 wt% of the hydrophobic monomer B and small amounts of the hydrophilic monomers Ae and Ce (BAeCe-9551 and BAeCe-8111), being more efficient than two commercial demulsifiers (FDH-1 and F-46 TRETOLITE™). Moreover, the BAeCe-9551 terpolymer was evaluated in a fresh heavy crude oil of 20.2 °API at 60 °C — temperature of separation tanks —, showing better performance as breaker, coalescer, and clarifier than FDH-1. Finally, a quantitative structure–activity relationship (QSAR) analysis was carried out employing terpolymers’ molecular parameters and crude oils’ physicochemical parameters. Only one equation fulfilled all thresholds for Q F 1 2 , Q F 2 2 , Q F 3 2 , and r m 2 parameters, proving to be the most accurate to predict the water removal efficiency (WRE) of BAeCe-1 and BAeCe-2 series terpolymers when added to heavy crude oils. This correlation will allow selecting the best terpolymer for demulsifying a petroleum stream as a function of its physicochemical characteristics.

Ethylene/Propylene/Diene Terpolymers Grafted with Poly(methyl acrylate) by Reverse Atom Transfer Radical Polymerization

AbstractThis article describes the synthesis of ethylene‐propylene‐diene terpolymers grafted with poly(methyl acrylate) (PMA) by reverse atom transfer radical polymerization. The PMA graft molecular weights and densities are controlled by varying the concentration and conversion of methyl acrylate, as well as the concentration of initiator. The grafted copolymers are characterized by Fourier‐transform infrared spectroscopy, proton NMR, and gel permeation chromatography. Copolymers with graft molecular weights varying from 12 to 179 kDa and grafting densities from 11% to 53% are made following this procedure.

Experimental study on an oil‐based polymer gel for lost circulation control in high‐temperature fractured formation

AbstractAiming at the lack of plugging agent for oil‐based drilling fluid leakage in fractured formation, an oil‐based gel‐plugging agent with high structural strength and strong thermal stability was synthesized based on monomer polymerization and crosslinking. According to the preparation experiment, when the total concentration of methyl methacrylate (MMA) and butyl acrylate (BA) is 30% and the ratio is 6:4, the oil‐based gel solution can be completely gelatinized from 80 to 200°C, which has high gel strength and controllable gelation time. The effects of total concentration of BA and MMA, the ratio of BA and MMA, synthesis temperature, oil‐based drilling fluid invasion, shear effect, and fiber concentration on gelling performance were systematically studied. Fourier transform infrared molecular structure analysis showed that the oil‐based gel contained benzene ring group and ester characteristic group. From the rheological properties of oil‐based gel with 30% gelling agent at 160°C, it could be seen that the elastic modulus G′ of 10 Hz is 232 kPa, which is much larger than the storage modulus G″ is 99 kPa, which reflects the solid properties and has good elasticity and high strength. The displacement experiment of sand filling pipe and dynamic and static plugging experiment of high temperature and high pressure shows that the oil‐based gel has high bearing capacity in fractures and sand filling pipe. The bearing pressure is 3.01 MPa in 6 mm fractures, and the bearing pressure gradient is 0.602 MPa/cm.

Compositional effects on cure kinetics, mechanical properties and printability of dual-cure epoxy/acrylate resins for DIW additive manufacturing

Interest in 3D printing of thermoset resins has increased significantly in recent years. One approach to additive manufacturing of thermoset resins is printing dual-cure resins with direct ink write (DIW). Dual-cure resins are multi-component resins which employ an in situ curable constituent to enable net-shape fabrication while a second constituent and cure mechanism contribute to the final mechanical properties of the printed materials. In this work, the cure kinetics, green strength, printability, and print fidelity of dual-cure epoxy/acrylate thermoset resins are investigated. Resin properties are evaluated as a function of acrylate concentration and in situ UV exposure conditions. The acrylate cure kinetics are probed using photo-differential scanning calorimetry and the impacts of resin composition and UV cure profile on the acrylate extent of conversion are presented. Continuous and pulsed UV cure profiles are shown to affect total conversion due to variances in radical efficiency at different UV intensities and acrylate concentrations. The effects of acrylate concentration on the kinetics of the epoxy thermal cure and the final mechanical properties are also investigated using dynamic mechanical analysis and three-point bend measurements. The glass transition temperature is dependent on formulation, with increasing acrylate content decreasing the Tg. However, the room temperature shear moduli, flexural moduli, strength, strain-to-failure, and toughness values are relatively independent of resin composition. The similarity of the final properties allows for greater flexibility in resin formulation and in situ cure parameters, which can enable the printing of complex parts that require high green strength. We found that the in situ UV print intensities and exposure profiles that are necessary to achieve the best print quality are not, in most cases, the conditions that maximize conversion of the acrylate network. This highlights the importance of developing optimized resin compositions which enable complete cure of the acrylate network by promoting acrylate dark cure or thermal cure.

Hierarchically Porous Microspheres by Thiol-ene Photopolymerization of High Internal Phase Emulsions-in-Water Colloidal Systems.

A facile method for the preparation of hierarchically porous spherical particles using high internal phase water-in-oil-in-water (w/o/w) double emulsions via the photopolymerization of the water-in-oil high internal phase emulsion (w/o HIPE) was developed. Visible-light photopolymerization was used for the synthesis of microspherical particles. The HIP emulsion had an internal phase volume of 80% and an oil phase containing either thiol pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) or trimethylolpropane tris(3-mercaptopropionate) (TMPTMP) and acrylate trimethylolpropane triacrylate (TMPTA). This enabled the preparation of microspheres with an open porous morphology, on both the surface and within the microsphere, with high yields in a batch manner. The effect of the thiol-to-acrylate ratio on the microsphere diameter, pore and window diameter, and degradation was investigated. It is shown that thiol has a minor effect on the microsphere and pore diameter, while the acrylate ratio affects the degradation speed, which decreases with increasing acrylate content. The possibility of free thiol group functionalization was demonstrated by a reaction with allylamine, while the microsphere adsorption capabilities were tested by the adsorption of methylene blue.

Reversible addition–fragmentation chain transferbased copolymers of acrylonitrile and alkyl acrylates as possible precursors for carbon fibers: synthesis and thermal behavior during stabilization

AbstractCopolymers of acrylonitrile and alkyl acrylates with various alkyl substituents (methyl, ethyl, butyl, 2‐ethylhexyl and lauryl) were synthesized via reversible addition–fragmentation chain transfer polymerization in dimethylsulfoxide. It is demonstrated that reactivity of alkyl acrylate in copolymerization decreases with increase of the length of the alkyl substituent. The molar fractions of homodiads and homotriads of acrylonitrile and the number‐average sequence length of acrylonitrile units decreases with a decrease in the acrylate content in the copolymer or with an increase in the length of the alkyl substituent in the acrylate. The copolymer composition was held constant throughout copolymerization in all the studied systems resulting in the formation of copolymers with high compositional homogeneity. Additionally the reversible addition–fragmentation chain transfer mechanism provides low dispersity of the copolymers. Both factors enable the effect of the alkyl substituent in alkyl acrylate on the thermal behavior of acrylonitrile copolymers to be carefully revealed. Being inert in the cyclization reaction, alkyl acrylates have no effect on the activation energy of the reaction. However, increase of the length of the alkyl substituent is followed by a slower evolution of the ladder structure. In contrast, in conditions of oxidative stabilization, the stabilization index increases in the order of increase of the number‐average sequence length of the acrylonitrile units in the copolymers. Thus, the use of alkyl acrylates with longer alkyl substituents provides an increase of chain flexibility and the formation of an enhanced ladder structure during oxidative stabilization which is profitable for carbon fiber production. © 2021 Society of Industrial Chemistry.

Protective Coatings Having Renewable Content Contributing towards Sustainability in Buildings

AbstractMost of the materials and world economy are based on petroleum and other related non‐renewable resources. In today's time, there is growing concern worldwide for the rapidly decreasing petroleum‐based resources. Hence, among the researchers around the world, more and more focus is growing on development of materials that are partially or totally independent of non‐renewable petroleum origin resources and are sustainable. In the research group, works has been going on reducing the non‐renewable contents in building materials and especially in developing the protective coatings. Under this work, studies are carried out to see how additions of plant extracts affect the properties of acrylic resin. Also, attempts are being made to modify acrylic resin using these plant extracts to get better systems. In this paper, effect of plant extracts obtained from local plants on some of the properties of acrylic resin is described. During the investigations, it is found that when acrylic content is replaced with plant extracts up to 25%, properties do not show any adverse effect on coating behavior.

Cationic Co(I) Catalysts for Regiodivergent Hydroalkenylation of 1,6-Enynes. An Uncommon cis-β-C-H Activation Leads to Z-Selective Coupling of Acrylates.

Two intermolecular hydroalkenylation reactions of 1,6-enynes are presented which yield substituted 5-membered carbo- and -heterocycles. This reactivity is enabled by a cationic bis-diphenylphosphinopropane (DPPP)CoI species which forms a cobaltacyclopentene intermediate by oxidative cyclization of the enyne. This key species interacts with alkenes in distinct fashion, depending on the identity of the coupling partner to give regiodivergent products. Simple alkenes undergo insertion reactions to furnish 1,3-dienes whereby one of the alkenes is tetrasubstituted. When acrylates are employed as coupling partners, the site of intermolecular C-C formation shifts from the alkyne to the alkene motif of the enyne, yielding Z-substituted-acrylate derivatives. Computational studies provide support for our experimental observations and show that the turnover-limiting steps in both reactions are the interactions of the alkenes with the cobaltacyclopentene intermediate via either a 1,2-insertion in the case of ethylene, or an unexpected β-C-H activation in the case of most acrylates. Thus, the H syn to the ester is activated through the coordination of the acrylate carbonyl to the cobaltacycle intermediate, which explains the uncommon Z-selectivity and regiodivergence. Variable time normalization analysis (VTNA) of the kinetic data reveals a dependance upon the concentration of cobalt, acrylate, and activator. A KIE of 2.1 was observed with methyl methacrylate in separate flask experiments, indicating that C-H cleavage is the turnover-limiting step in the catalytic cycle. Lastly, a Hammett study of aryl-substituted enynes yields a ρ value of -0.4, indicating that more electron-rich substituents accelerate the rate of the reaction.

Synthesizing environmentally friendly non-silicone oxygen bleaching stabilizer for linen yarn using oligomeric acrylic acid

Using potassium peroxodisulfate as an initiator and acrylic acid as a monomer, an acrylic acid oligomer was synthesized and then compounded with magnesium salt to form a non-silicone oxygen bleaching stabilizer. By investigating the effects of reaction temperature, reaction time, initiator concentration, monomer concentration, and magnesium salt dosage on product performance, the effect of stabilizers on linen yarn bleaching was analyzed. The synthetic conditions of oxygen bleaching stabilizer were determined by orthogonal test method, namely, acrylic acid monomer concentration 25%, initiator dosage 5%, oligomeric acrylic acid and magnesium salt compound ratio 5:1, reaction temperature 65 °C, reaction time 4 h. At this time, the chelated iron value of the product was as high as 239.314 mg/g, and the chelated calcium value also reached 145.000 mg/g. The dosage of the synthesized stabilizer were determined to be 4 g/L through indicators such as the decomposition rate of hydrogen peroxide and whiteness. The results showed that the environmentally friendly non-silicone oxygen bleaching stabilizer not only had a good ability to inhibit the decomposition of hydrogen peroxide, but also provided bleached linen yarn with a superior degree of whiteness and less metal ion residue, which can effectively solve the “silicon scale” problem and improve the quality of the pre-treatmented products.

Synthesis, Surface Tension, Flocculation and Antibacterial Properties of Cationic Copolymer Methacryloxyethyl Trimethyl Ammonium Chloride-Butyl Acrylate-Acrylamide

Abstract Three cationic copolymers methacryloxyethyl trimethyl ammonium chloride-butyl acrylate-acrylamide (MTAC-BA-AM terpolymer) were designed and synthesized by emulsion polymerization. Their structures were confirmed by FT-IR and 1H NMR. The effect of content of hydrophobic monomer butyl acrylate (BA) in MTAC-BA-AM terpolymer on surface activities, flocculation and antibacterial properties were investigated. The study of surface tension shows that MTAC-BA-AM terpolymer has good surface activity due to the introduction of hydrophobic monomer BA. The flocculation experiment showed that the light transmittance of the kaolin suspension supernatant was 98.13% when the dose of MTAC-BA-AM terpolymer in the kaolin suspension was 0.03 mg/L, which was obviously better than the P(MTAC-AM) (91.02%) without hydrophobic modification of BA. The bacteriostatic experiment of MTAC-BA-AM terpolymer showed that as the content of hydrophobic monomer BA in MTAC-BA-AM terpolymer increased the inhibitory rate of MTAC-BA-AM terpolymer aginst Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus)

A study on comfort properties of oak Tasar silk waste and acrylic blended fabrics

Oak Tasar is wild silk with natural golden brown colour and unique texture available in Himalayan region of India. A lot of fibre waste is generated during hand spinning of oak Tasar silk yarn which can be utilized by blending it with compatible fibre to incorporate the properties of both fibres in the yarn. The present study aimed to develop Oak Tasar silk waste and acrylic blended fabrics and study their comfort properties. The oak Tasar silk and acrylic blended plain weave and twill weave fabrics were prepared with five different blend ratios viz. 100:0, 60:40, 50:50, 40:60 and 0:100. The prepared fabrics were studied for comfort properties like thermal insulation (clo, TIV %), Q-max (warm/cool feeling), air permeability, water vapour transport rate and were statistically analysed. Results revealed that thermal insulation and clo value were found to be increased with increasing acrylic content in the fabric whereas Q- max, air permeability, water vapour permeability values were reduced with the addition of oak Tasar silk fiber in the blend. The 50:50 blended plain weave fabric among the blended fabrics had the highest clo value, i.e. 0.52 and 50:50 blended twill weave fabric had highest Q max value i.e. 0.109W/cm2. It was found from the study that the developed fabrics are comfortable and can be used for light winters.

Microbial metabolites in the gut‐brain axis of an amyotrophic lateral sclerosis model

Backgound Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder characterized by progressive atrophy of motor neurons. Recent studies have demonstrated gut microbiome-associated contributions to human ALS and ALS experimental mice SOD1­G93A. Treatment with dietary butyrate, a natural bacterial product, rectified intestinal abnormalities and reduced disease progression in ALS mice. The emergence of ALS as a multifactorial disorder is further emphasized by understanding gut-brain mechanisms such as microbial metabolites. Methods Here, we hypothesize that butyrate treatment increases the concentration of anti-inflammatory and neuroprotective metabolites. SOD1­G93A (G93A) mice were used as a model of human ALS. G93A and WT mice classified as treated and untreated groups. Treated groups were given 2% dietary butyrate in their drinking water while untreated were given water ad libitum. Fecal samples were collected at 4, 8 and 14 weeks of age for treated groups while samples for untreated groups were obtained at 4, 7,13, and 17 weeks of age. Metabolites in fecalsamples were prepared using the automated MicroLab STAR® system (Hamilton Company) and measured by Metabolon. Raw data were extracted, peak-identified and QC processed using Metabolon's hardware and software. Statistical comparisons between metabolite concentrations in untreated and treated groups were conducted using two-way ANOVA via R. Results In untreated G93A mice, there was an increase in indole derived metabolites at 13 weeks of age, at onset of ALS symptoms. Specifically, concentration of indole acetate and indole acrylate, which are known to be aryl hydrocarbon receptor (AhR) ligands which indirectly aid in neuroprotection, increased at 13 weeks. Additionally, endocannabinoid concentrations, such as behenoyl ethanolamide (BEA) increased at 13 weeks while linoleoyl ethanolamide (LigEA) increased at 17 weeks. Our results suggest that the increased production of anti-inflammatory and neuroprotective metabolites onset and at 17 weeks could be a compensatory mechanism by the gut to alleviate ALS pathology. We also identify specific microbial metabolites associated with ALS as well as investigate the effect of butyrate on metabolites over the course of disease. Conclusion This study profiled fecal metabolites in G93A mice at different stages of ALS and with butyrate treatment. Four metabolites emerged as metabolic markers with diagnostic potential. Our findings contribute to the notion that the gut microbiome may play an essential role in the pathogenesis and pathophysiology of ALS and have significant translational implications for identifying new biomarkers for ALS. Further investigation is needed to explore whether related genes or enzymes could elucidate biological mechanisms of how ALS develops at the systemic level.

Influence of UV Polymerization Curing Conditions on Performance of Acrylic Pressure Sensitive Adhesives.

Acrylic pressure sensitive adhesives (PSAs) were prepared by UV polymerization under varying curing conditions of both fast and slow curing, employing high- and low-intensity UV radiation, respectively. The influences of curing conditions and isobornyl acrylate (IBOA) content on PSA performance were comprehensively investigated by measurement of their rheological, thermal, and adhesive properties. In particular, rheological characterization was accomplished by several analytical methods, such as in situ UV rheology, frequency sweep, stress relaxation, and temperature ramp tests, to understand the effect of the UV curing process and IBOA content on the viscoelastic behavior of acrylic PSAs. The slow-cured samples were observed to form more tightly crosslinked networks compared to the fast-cured. On the other hand, at high loading levels of IBOA, in the case of slow curing, the sample exhibited a contrasting trend, having the shortest stress relaxation time and the highest energy dissipation; this was due to molecular chain scission occurring in the crosslinked polymer during UV polymerization. Consequently, we successfully demonstrated the influence of monomer composition of acrylic PSAs, and that of curing conditions employed in UV polymerization. This study provides valuable insights for the development of crosslinked polymer networks of acrylic PSAs for flexible display applications.