Showing papers on "Methacrylic acid published in 2021"

Production and Polymerization of Biobased Acrylates and Analogs.

Abstract: To prepare biobased polymers, particular attention must be paid to the obtention of the monomers from which they are derived. (Meth)acrylates and their analogs constitute such a class of monomers that have been extensively studied due to the wide range of polymers accessible from them. This review therefore aims to highlight the progresses made in the production and polymerization of (meth)acrylates and their analogs. Acrylic acid production from biomass is close to commercialization, as three different high-potential intermediates are identified: glycerol, lactic acid, and 3-hydroxypropionic acid. Biobased methacrylic acid is less common, but several promising options are available, such as the decarboxylation of itaconic acid or the dehydration of 2-hydroxyisobutyric acid. Itaconic acid is also a vinylic monomer of great interest, and polymers derived from it have already found commercial applications. Methylene butyrolactones are promising monomers, obtained from bioresources via three different intermediates: levulinic, succinic, or itaconic acid. Although expensive, methylene butyrolactones have a strong potential for the production of high-performance polymers. Finally, β-substituted acrylic monomers, such as cinnamic, fumaric, muconic, or crotonic acid, are also examined, as they provide an original access to biobased materials from various renewable raw materials, such as protein waste, lignin, or wastewater.

The Effects of Monomer, Crosslinking Agent, and Filler Concentrations on the Viscoelastic and Swelling Properties of Poly(methacrylic acid) Hydrogels: A Comparison

Abstract: The present work aims at comparatively studying the effects of the concentrations of a monomer (10–30 wt% based on the whole hydrogel composition), crosslinking agent (1–3 mol% based on the monomer), and reinforcing agent (montmorillonite-MMT, 1–3 wt.% based on the whole hydrogel composition) on the swelling and viscoelastic properties of the crosslinked hydrogels prepared from methacrylic acid (MAA) and N,N′-methylenebisacrylamide (BIS) in the presence of K2S2O8 in aqueous solution. The viscoelastic measurements, carried out on the as-prepared hydrogels, showed that the monomer concentration had the largest impact, its three-time enhancement causing a 30-fold increase in the storage modulus, as compared with only a fivefold increase in the case of the crosslinking agent and 1.5-fold increase for MMT in response to a similar threefold concentration increase. Swelling studies, performed at three pH values, revealed that the water absorption of the hydrogels decreased with increasing concentration of both the monomer and crosslinking agent, with the amplitude of the effect of concentration modification being similar at pH 5.4 and 7.4 in both cases, but very different at pH 1.2. Further, it was shown that the increased pH differently influenced the swelling degree in the case of the hydrogel series in which the concentrations of the monomer and crosslinking agent were varied. In contrast to the effect of the monomer and crosslinking agent concentrations, the increase in the MMT amount in the hydrogel resulted in an increased swelling degree at pH 5.4 and 7.4, while at pH 1.2, a slight decrease in the water absorption was noticed. The hydrogel crosslinking density determinations revealed that this parameter was most affected by the increase in the monomer concentration.

Synthesis, characterization and rheological study of Arabic gum-grafted-poly (methacrylic acid) hydrogels

Abstract: Hydrogel synthesis from synthetic and natural polymers display mutual advantages in terms of mechanical strength, biocompatibility, and degradation Hydrogels have emerged as one of the most effective carriers for drug and therapeutic agents in control delivery In this research, Arabic gum, a natural polymer and methacrylic acid (synthetic polymer) was grafted through free radical polymerization method to form a smart hydrogel The non-toxic and biocompatible hydrogels were characterized via Fourier Transform Infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction analysis The morphology was analyzed by field emission scanning electron microscopy (FESEM) and the mechanical properties by rheological studies The reaction variables were studied by changing the concentration of initiator, monomer and cross-linking agent Swelling study revealed high swelling in hydrogels with higher concentration of initiator and a low swelling in hydrogels with higher concentration of cross-linker and monomers; this confirmed the influence of the reacting variables on the swelling Swelling kinetics follow second order non-Fickian mechanism which depends on the pH and composition of the hydrogel The rheology revealed the mechanical properties of the hydrogels by amplitude and frequency sweep tests of the elastic modulus and viscous moduli The storage modulus is higher for hydrogels with high concentration of monomers but lower in hydrogels with high concentration of initiator and cross-linking agents The degradation depends on the ratio of monomer and cross-linking agents, least degradation was observed in hydrogels with higher percentage of cross-linking agents The properties displayed reveals the potentials of the Arabic gum-grafted hydrogels for agricultural, biomedical and pharmaceutical applications

Novel Multifunctional Epoxy (Meth)Acrylate Resins and Coatings Preparation via Cationic and Free-Radical Photopolymerization

Abstract: In this work, a series of novel multifunctional epoxy (meth)acrylate resins based on a low-viscosity aliphatic triepoxide triglycidyl ether of trimethylolethane (TMETGE) and acrylic acid (AA) or methacrylic acid (MMA) have been synthesized Thanks to the performed modification, the obtained prepolymers have both epoxides as well as carbon-carbon double bonds and differ in their amount The obtained results indicate that the carboxyl-epoxide addition esterification occurs in the presence of a catalyst (triphenylphosphine) at a temperature of 90 °C, whilst the required degree of conversion can be achieved simply by varying both the reagents ratio and reaction time The structure of synthesized copolymers was confirmed by spectroscopic analyses (FT-IR, 1H NMR, 13C NMR) and studied regarding its nonvolatile matter content (NV), acid value (PAVs), as well as its epoxy equivalent value (EE) Due to the presence of both epoxy and double carbon-carbon pendant groups, one can apply two distinct mechanisms: (i) cationic ring-opening polymerization or (ii) free-radical polymerization to crosslink polymer chains Synthesized epoxy (meth)acrylate prepolymers were further employed to formulate photocurable coating compositions Hence, when cationic photoinitiators were applied, polyether-type polymer chains with pending acrylate or methacrylate groups were formed In the case of free-radical polymerization, epoxy (meth)acrylates certainly formed a poly(meth)acrylate backbone with pending epoxy groups Further, photopolymerization behavior and properties of cured coatings were investigated regarding some structural factors and parameters Moreover, reaction rate coefficients of photo-cross-linking by both cationic ring-opening and free-radical photopolymerization of the received epoxy (meth)acrylate resins were determined via real-time infrared spectroscopy (RT-IR) Lastly, basic physicomechanical properties, such as tack-free time, hardness, adhesion, gloss, and yellowness index of cured coatings, were evaluated

Removal of bisphenol A from aqueous media using a highly selective adsorbent of hybridization cyclodextrin with magnetic molecularly imprinted polymer.

Abstract: In this study, a unique magnetic molecularly imprinted polymer (MMIP) adsorbent towards bisphenol A (BPA) as a template molecule was developed by bulk polymerization using β-cyclodextrin (β-CD) as a co-monomer with methacrylic acid (MAA) to form MMIP MAA-βCD as a new adsorbent. β-CD was hybridized with MAA to obtain water-compactible imprinting sites for the effective removal of BPA from aqueous samples. Benzoyl peroxide and trimethylolpropane trimethacrylate were used as the initiator and cross-linker, respectively. The adsorbents were characterized by Fourier transform infrared spectroscopy, scanning electronic microscopy, transmission electron microscopy, vibrating sample magnetometer, Brunauer-Emmett-Teller and X-ray diffraction. 1H nuclear magnetic resonance spectroscopy was used to characterize the MAA-βCD and BPA-MAA-βCD complex. Several parameters influencing the adsorption efficiency of BPA such as adsorbent dosage, pH of sample solution, contact time, initial concentrations and temperature as well as selectivity and reusability study have been evaluated. MMIP MAA-βCD showed significantly higher removal efficiency and selective binding capacity towards BPA compared to MMIP MAA owing to its unique morphology with the presence of β-CD. The kinetics data can be well described by the pseudo second-order kinetic and Freundlich isotherm and Halsey models best fitted the isotherm data. The thermodynamic studies indicated that the adsorption reaction was a spontaneous and exothermic process. Therefore, MMIP based on the hybrid monomer of MAA-βCD shows good potential of a new monomer in molecularly imprinted polymer preparation and can be used as an effective adsorbent for the removal of BPA from aqueous solutions.

In situ synthesis of silver nanoparticles on modified poly(ethylene terephthalate) fibers by grafting for obtaining versatile antimicrobial materials

Abstract: Because of having high mechanical properties and cheapness of PET textiles, functionalization of them for new properties is an active research area. In the present work, methacrylic acid (MAA)-grafted PET fibers (PET-g-MAA) were obtained by grafting of MAA monomers to PET surface for an antimicrobial material synthesis. The morphologies of the obtained graft copolymers were examined with a scanning electron microscopy (SEM), and the chemical modification after grafting was determined with Fourier-transform infrared spectroscopy (FTIR) analysis. Subsequently, silver ions were adsorbed onto the PET-g-MAA fibers surface and the adsorbed ions to the surface were reduced to silver nanoparticles (AgNPs) by UVC light. The morphology of fiber surfaces modified with MAA and coated with AgNPs was examined by SEM studies, and it was observed that AgNPs were disturbed along the fibers. The presence of silver on the surface was also confirmed by energy-dispersive X-ray spectroscopy (EDS) and energy dispersion X-ray fluorescence spectrometry (EDXRF). The crystalline structure of the original PET fiber, PET-g-MAA fiber and PET-g-MAA fiber modified with AgNPs was investigated by X-ray diffraction (XRD). The thermal properties of the obtained fibers were investigated by thermogravimetric analysis (TGA). The immobilization of AgNPs on the grafted fibers leads to a change on the patterns of TGA curves. The most significant change is the less weight reduction in the temperature range of 200–300°C. Disk diffusion test was performed using Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25,922) bacteria in order to investigate the antibacterial ability of the obtained fibers, and it was found that the fibers coated with AgNPs had antibacterial effect on both bacterial species. The cytotoxicity of the groups with the best antibacterial properties was determined by MTT test, and the synthesized material did not have cytotoxic effects on L929 fibroblast cells. The material obtained has the potential to be used in antimicrobial applications.

Intracellular delivery of budesonide and polydopamine co-loaded in endosomolytic poly(butyl methacrylate-co-methacrylic acid) grafted acetalated dextran for macrophage phenotype switch from M1 to M2

Abstract: In this study, a rationally designed nanocomposite (BUDPDA@MAP) composed of polydopamine (PDA) nanoparticle and anti‐inflammatory drug budesonide (BUD) encapsulated in a pH‐responsive endosomolytic polymer (poly(butyl methacrylate‐co‐methacrylic acid) grafted acetalated dextran, denoted by MAP), is proposed. The uniform nanocomposite is prepared using a microfluidic device. At low endosomal pH (5.5), MAP destabilizes the endosomal membranes for the cytoplasmic delivery of PDA, and releases BUD simultaneously, resulting in a greater reactive oxygen species scavenging capability than both the free drug and PDA alone. The combined therapeutic efficacy from PDA and BUD also leads to a successful macrophage phenotype switch from pro‐inflammatory M1 to anti‐inflammatory M2.

Water-Resistant Latex Coatings: Tuning of Properties by Polymerizable Surfactant, Covalent Crosslinking and Nanostructured ZnO Additive

Abstract: This paper deals with the development of acrylic latexes providing high-performance water-resistant coatings. For this purpose, mutual effects of anionic surfactant type (ordinary and polymerizable), covalent intra- and/or interparticle crosslinking (introduced by allyl methacrylate copolymerization and keto-hydrazide reaction, respectively) and ionic crosslinking (provided by nanostructured ZnO additive) were investigated. The latexes were prepared by the standard emulsion polymerization of methyl methacrylate, butyl acrylate and methacrylic acid as the main monomers. The addition of surface-untreated powdered nanostructured ZnO was performed during latex synthesis, resulting in stable latexes comprising dispersed nanosized additive in the content of ca 0.9−1.0 wt.% (based on solids). The coating performance with emphasis on water resistance was evaluated. It was determined that the application of the polymerizable surfactant improved coating adhesion and water-resistance, but it wasn′t able to ensure high water-resistance of coatings. Highly water-resistant coatings were obtained provided that covalent intra- and interparticle crosslinking together with ionic crosslinking were employed in the coating composition, forming densely crosslinked latex films. Moreover, coatings comprising nanostructured ZnO additive displayed a significant antibacterial activity and improved solvent resistance.

Molecularly imprinted polymer based on metal-organic frameworks: synthesis and application on determination of dibutyl phthalate

Abstract: The molecular surface imprinted graft copolymer of metal-organic framework MOF-5 with methacrylic acid were prepared by free radical polymerization with dibutyl phthalate as the template molecule u...

Functionalized crosslinked interpenetrating polymeric network for pH responsive colonic drug delivery

Abstract: Current exploration unveils the promising role of arabinoxylan (AX) in targeted delivery of acid labile active moiety, by using methacrylic acid (MAA) as monomer, N′,N′-methylene-bis-acrylamide (MB...

A Magnetic, Core–Shell Structured, pH-Responsive Molecularly Imprinted Polymers for the Selective Detection of Sulfamethoxazole

Abstract: A magnetic, core–shell structured pH-responsive molecularly imprinted polymer was prepared by surface imprinting technique and free radical polymerization for selective extraction of sulfamethoxazole. The imprinted polymer shell was prepared using 2-(Dimethylamino) ethyl methacrylate as pH-sensitive monomer, a certain amount of 4-vinylphenylbronic acid and methacrylic acid as common monomer to increase selectivity, sulfamethoxazole as template molecules. Excellent adsorption capacity (39.06 mg g−1) and selectivity (IF = 2.19) were achieved and the capture/release process can be regulated by pH value. In addition, it has been successfully applied to the detection of sulfamethoxazole in water samples and the recovery rate reached 96.2%. This study provides a new method and idea for the selective separation and detection of sulfamethoxazole in actual samples.

Control of Particle Size in the Self-Assembly of Amphiphilic Statistical Copolymers.

Abstract: A range of amphiphilic statistical copolymers is synthesized where the hydrophilic component is either methacrylic acid (MAA) or 2-(dimethylamino)ethyl methacrylate (DMAEMA) and the hydrophobic component comprises methyl, ethyl, butyl, hexyl, or 2-ethylhexyl methacrylate, which provide a broad range of partition coefficients (log P). Small-angle X-ray scattering studies confirm that these amphiphilic copolymers self-assemble to form well-defined spherical nanoparticles in an aqueous solution, with more hydrophobic copolymers forming larger nanoparticles. Varying the nature of the alkyl substituent also influenced self-assembly with more hydrophobic comonomers producing larger nanoparticles at a given copolymer composition. A model based on particle surface charge density (PSC model) is used to describe the relationship between copolymer composition and nanoparticle size. This model assumes that the hydrophilic monomer is preferentially located at the particle surface and provides a good fit to all of the experimental data. More specifically, a linear relationship is observed between the surface area fraction covered by the hydrophilic comonomer required to achieve stabilization and the log P value for the hydrophobic comonomer. Contrast variation small-angle neutron scattering is used to study the internal structure of these nanoparticles. This technique indicates partial phase separation within the nanoparticles, with about half of the available hydrophilic comonomer repeat units being located at the surface and hydrophobic comonomer-rich cores. This information enables a refined PSC model to be developed, which indicates the same relationship between the surface area fraction of the hydrophilic comonomer and the log P of the hydrophobic comonomer repeat units for the anionic (MAA) and cationic (DMAEMA) comonomer systems. This study demonstrates how nanoparticle size can be readily controlled and predicted using relatively ill-defined statistical copolymers, making such systems a viable attractive alternative to diblock copolymer nanoparticles for a range of industrial applications.

Thermodynamic Theory of Multiresponsive Microgel Swelling

Abstract: Using a thermodynamic theory, we present a systematic study of the behavior of microgels of N-isopropylacrylamide (NIPAm) and methacrylic acid (MAA) copolymers as a function of the temperature, pH,...

Poly(n-vinylpyrrolidone-co-acrylonitrile-co-methacrylic acid)–graphene quantum dot conjugate: synthesis and characterization for sensing ammonia vapour

Abstract: Ammonia is a toxic gas that can cause various respiratory diseases. There are many ammonia sources such as chemical industries, laboratories, and life-stock, in addition to its natural origin. Hence, the detection of ammonia is of utmost importance. Herein, we report a bio-based synthesis of graphene quantum dots using the leaf extracts of Elaeocarpus serratus. The quantum dots were found to emit bright pink colour under a UV lamp. Further, the synthesized quantum dots were complexed with poly(n-vinylpyrrolidone-co-acrylonitrile-co-methacrylic acid) via in situ incorporation. All the synthesized materials were well characterized using various sophisticated techniques. The polymer composite was found to have enhanced electrical properties compared to the original copolymer. At 80 °C, the AC conductivity of the copolymer and the polymer–GQD composite was found to be 1.9 × 10−7 and 1.6 × 10−5 S cm−1, respectively. The activation energy of the copolymer was increased from 0.115 to 0.725 on forming the composite. The copolymer showed no ionic nature, whereas the polymer composite was found to be 61.56% ionic in nature. A portable electronic device was fabricated using the polymer composite for the selective and reversible detection of ammonia vapour in the presence of other organic vapours, with a detection limit of 0.232 ppm. A two-fold decrease in the impedance value was observed in the presence of ammonia vapour at room temperature, while the current–voltage characteristic plot showed a five-fold increase in current density at 90 °C in the presence of ammonia vapour. Such a drastic change in the electrical properties of the sensor is attributed to the weak physisorption of the ammonia vapour in the polymer matrix. Furthermore, to check the sensor's practical applications, we studied its impedance response in the presence of the gases released from the rotten fish sample. Interestingly, the sensor showed a significant decrease in the impedance which indicates that the polymer composite could be used for the real-time detection of ammonia.

Synthesis of Poly(methacrylic acid-co-butyl acrylate) Grafted onto Functionalized Carbon Nanotube Nanocomposites for Drug Delivery.

Abstract: Design of a smart drug delivery system is a topic of current interest. Under this perspective, polymer nanocomposites (PNs) of butyl acrylate (BA), methacrylic acid (MAA), and functionalized carbon nanotubes (CNTsf) were synthesized by in situ emulsion polymerization (IEP). Carbon nanotubes were synthesized by chemical vapor deposition (CVD) and purified with steam. Purified CNTs were analyzed by FE-SEM and HR-TEM. CNTsf contain acyl chloride groups attached to their surface. Purified and functionalized CNTs were studied by FT-IR and Raman spectroscopies. The synthesized nanocomposites were studied by XPS, 13C-NMR, and DSC. Anhydride groups link CNTsf to MAA–BA polymeric chains. The potentiality of the prepared nanocomposites, and of their pure polymer matrices to deliver hydrocortisone, was evaluated in vitro by UV–VIS spectroscopy. The relationship between the chemical structure of the synthesized nanocomposites, or their pure polymeric matrices, and their ability to release hydrocortisone was studied by FT-IR spectroscopy. The hydrocortisone release profile of some of the studied nanocomposites is driven by a change in the inter-associated to self-associated hydrogen bonds balance. The CNTsf used to prepare the studied nanocomposites act as hydrocortisone reservoirs.

Isotherm and Electrochemical Properties of Atrazine Sensing Using PVC/MIP: Effect of Porogenic Solvent Concentration Ratio

Abstract: Widespread atrazine use is associated with an increasing incidence of contamination of drinking water. Thus, a biosensor using molecularly imprinted polymers (MIPs) was developed to detect the amount of atrazine in water to ensure prevention of exposure levels that could lead to reproductive effects in living organisms. In this study, the influence of the porogen on the selectivity of MIPs was investigated. The porogen plays a pivotal role in molecular imprinting as it affects the physical properties and governs the prepolymerization complex of the resulting polymer, which in turn firmly defines the recognition properties of the resulting molecularly imprinted polymer (MIP). Therefore, bulk MIPs against atrazine (Atr) were synthesized based on methacrylic acid (MAA) as a functional monomer and ethyleneglycol dimethacrylate (EGDMA) as a crosslinker; they were prepared in toluene and dimethyl sulfoxide (DMSO). The imprinting factor, binding capacity, and structural stability were evaluated using the respective porogenic solvents. Along with the characterization of the morphology of the obtained polymers via SEM and BET analysis, the kinetic and adsorption analyses were demonstrated and verified. The highest imprinting factor, binding capacity, and the highest structural stability were found to be on polymer synthesized in a medium of MAA and EGDMA, which contained 90% toluene and 10% DMSO as porogen. Moreover, the response for Atr concentrations by the PVC-based electrochemical sensor was found to be at a detection limit of 0.0049 μM (S/N = 3). The sensor proved to be an effective sensor with high sensitivity and low Limit of Detection (LOD) for Atr detection. The construction of the sensor will act as a baseline for a fully functionalized membrane sensor.

Selective Oxidation of Isobutane to Methacrylic Acid and Methacrolein: A Critical Review

Abstract: Selective oxidation of isobutane to methacrolein (MAC) and methacrylic acid (MAA) has received great interest both in the chemical industry and in academic research. The advantages of this reaction originate not only from the low cost of the starting material and reduced process complexity, but also from limiting the use of toxic reactants and the production of wastes. Successive studies and reports have shown that heteropolycompounds (HPCs) with Keggin structure (under the form of partially neutralized acids with increased stability) can selectively convert isobutane to MAA and MAC due to their strong and tunable acidity and redox properties. This review hence aims to discuss the Keggin-type HPCs that have been used in recent years to catalyze the oxidation of isobutane to MAA and MAC, and to review alternative metal oxides with proper redox properties for the same reaction. In addition, the influence of the main reaction conditions will be discussed.