Amounts Of Methacrylic Acid Research Articles

Soy protein isolate–based gel polymer electrolyte for flexible solid-state supercapacitor

At present, the polymer matrices of most polymer electrolytes are derived from petroleum-based synthetic polymers. Herein, sustainable and renewable soy protein isolate (SPI) was grafted with methacrylic acid (MAA) and then cross-linked by ring-opening reaction with polyethylene glycol diglycidyl ether as cross-linking agent to obtain a biomass-based polymer electrolyte. Results show that when the added amount of MAA is twice the quality of SPI, gel polymer electrolyte displays the best comprehensive properties and presents the highest ionic conductivity of 5.24 × 10−3 S/cm. The flexible supercapacitor was fabricated by using SPI-based gel polymer electrolyte with activated carbon electrodes, which exhibited excellent specific capacitance (128.63 F/g) and energy density (9.52 Wh/kg) at 0.5 A/g with a decent capacitance retention of 93% after 5000 charge–discharge cycles. It can be ascribed that grafting modification of SPI improves the interface performance of electrode–polymer electrolyte. Furthermore, potassium iodide is introduced to form a redox polymer electrolyte to achieve a high-energy-density supercapacitor, which provides outstanding energy density of 24.40 Wh/kg at 1.0 A/g. This work demonstrates that sustainable and renewable biomass can be converted into matrix of polymer electrolyte for high performance supercapacitor based on aqueous polymer electrolyte.

Synthesis and physicochemical characterization of Arabic gum microgels modified with methacrylic acid as potential drug carriers

Microgels of carbohydrate polymers are non-toxic and biocompatible that can readily be used in applications such as drug delivery, medicine, and pharmacy. In this work, Arabic gum (AG) microgels and methacrylic acid modified Arabic gum microgels (AGMAA) were synthesized via the water in oil emulsion polymerization technique using Tween 20 as the surfactant and hexane as the solvent. The microgels were characterized using various physicochemical methods such as Fourier transform infrared spectroscopy, thermal stability using differential scanning calorimetry, diffraction pattern analysis using X-Ray diffraction, morphology observation using field emission scanning electron microscopy and dynamic light scattering was used to analyze the size and zeta potential. The rate of deformation was higher in the AG microgels compared to the AGMAA microgels. The particle size and zeta potential of the AGMAA microgel were found to be larger and more negative than AG microgel, respectively. The particle size and zeta potentials of the microgels were found to be dependent on the amount of methacrylic acid as the modifying agent. The microgels were encapsulated with doxorubicin through the swelling method and the in vitro release was studied in mediums with pH values of 4.2 and 7.4. The results suggest the potentials of these microgels for drugs delivery.

Surface characterization of drying acrylic latex dispersions with variable methacrylic acid content using surface dilatational rheology

HypothesisDrying of latex dispersions often results in particle gradients at the latex-air interface. We expect that, by increasing the carboxylic acid content of latex particles, inter-particle interactions at the interface change. With dilatational rheology one could detect particle-particle interactions in an early stage of the drying process and elucidate the nature of these interactions. ExperimentsAcrylic latex dispersions were prepared with different amounts of methacrylic acid (MAA), ranging from 2 to 10 wt% on dry mass. Dilatational rheology studies during drying at different relative humidities RH were performed using profile analysis tensiometry. Visco-elastic properties of latex surfaces were used to identify inter-particle interactions at the surfaces depending on the drying rate and particle composition. FindingsDrying at 85% RH did not show significant changes of the mechanical properties of the latex surfaces. Drying at 65 and 53% RH resulted in a change of the mechanical properties, ultimately showing non-linear visco-elastic behavior. This indicates that capillary and/or Van der Waals forces were operating between particles at the surface. With increasing MAA content the viscous contribution decreased, possibly due to the formation of more gel-like structures at the particle surface due to higher solubility of polymer segments near to the surface.

Isolation of the interaction between CaCO3 filler and acrylic binder. Part II: Effect of the amount and type of functional monomer

The aim of this work is to better understand the effect that different functional monomers and amounts have on the dispersion of calcium carbonate (CaCO3) fillers in waterborne acrylic coatings. This will allow to improve the final performance of coatings at a certain pigment volume concentration (PVC) or to increase the PVC without significant losses in the properties. In this paper we report the preparation of CaCO3/poly(methyl methacrylate-co-butyl acrylate) P(MMA/BA) latex blends without the use of any additive and with applicable rheology. This has been possible thanks to the direct addition of CaCO3 powder to diluted latex. Paint-like blends have been prepared with latexes synthesized with acrylic acid (AA) and methacrylic acid (MAA) functional monomers at 1, 3, and 5 wt based on monomer percent (wbm%) and with itaconic acid (IA) at 1 wbm%, at different PVC values of 30, 40 and 50. Moreover, the effect of water soluble species on the final paint properties has been checked by dialyzing latexes synthesized with the minimum and the maximum amount of MAA, before the blending with CaCO3. The effect of all these variables has been investigated by analysing the final paint-like film properties (rheology, gloss, mechanical properties and scrub resistance). The interaction between the different latexes and CaCO3 filler was also studied by investigating the adsorption capacity of polymer particles on the surface of CaCO3 particles with NMR measurements. Higher gloss value, more elastic mechanical properties and higher scrub resistance have been observed for films prepared with the latex containing 1 wbm% of MAA functional monomer.

Hydroplasticization of latex films with varying methacrylic acid content

The hydroplasticization of coatings of acrylic copolymers with different amounts of methacrylic acid (MAA) was investigated to clarify the role of carboxylic acid functionalities on the change in polymer mobility due to water uptake. The coating Tg as a function of water uptake was studied using dynamic mechanical analysis. The Tg’s decreased with increasing water content, confirming the plasticizing effect of water on the coatings. At relative humidities RH between 0 and 60% the coating Tg shows a sharper decrease than at higher RH, an effect that increases with increasing MAA content. This behavior is attributed to the presence of dimers of carboxylic acid in the coatings, which is also observed with FTIR-ATR analyses. Due to water uptake, the dimers are disrupted and form “open” dimers where carboxylic acid groups remain in close proximity and are connected through water molecules. With 1H NMR relaxometry, two T2 relaxation times are found, representing two hydrogen pools with different mobilities. Both mobilities increase with increasing water content, indicating the presence of polymer domains with different hardness. Correlating the T2 relaxation times with the coating Tg’s shows that at higher MAA content the proton mobility as a function of Tg of the soft domains increases with increasing MAA content. Since the polymer proton mobility, and hence the polymer mobility, is expected to scale with the polymer Tg, it is hypothesized that harder domains are present in the coatings, which are not visible in the Ostroff-Waugh decays due to the fast relaxation behavior of these protons.

Fabrication of Ag and Au nanoparticles in cross-linked polymer microgels for their comparative catalytic study

Abstract Three dimensional cross-linked polymer microgels with temperature responsive N-isopropyl acrylamide (NIPAM) and pH sensitive methacrylic acid (MAA) were successfully synthesized by free radical emulsion polymerization with different amounts of MAA. Silver and gold nanoparticles with the size of 6.5 nm and 3.5 nm (±0.5 nm), respectively were homogeneously reduced inside these materials by chemical reduction method at pH 2.78 and 8.36 for the preparation of hybrid materials. The samples were characterized by FT-IR, DLS and TEM techniques. The catalytic activity of the hybrid materials was investigated for the reduction of 4-nitrophenol (4-NP) using NaBH4 as reducing agent by UV-Vis spectroscopy. The hybrid polymer network synthesized at pH 8.36 showed enhanced catalytic efficiency compared to the catalysts synthesized at pH 2.78. In this study, it has been stated that the catalyst activity strongly depends on the amount of MAA, pH value during synthesis and the type of entrapped metal nanoparticles.

Synthesis of opaque and colored hollow polymer pigments

A parametric study was carried out to investigate the effects of process parameters on the properties of opaque and/or colored polymer pigment. The core was synthesized using methyl methacrylate (MMA), methacrylic acid (MAA), and ethylene glycol dimethacrylate, and the shell from styrene. The surfactant/water (S/W) ratio was changed between 0.56 and 1.46, and the best ratio was determined to be 0.97. The increase in the amount of MAA and the pH of the medium increases the diameter of the swollen particles. The hollows could form only when the fraction of MAA in the monomer mixture was above 10%, and pH ≥ 10. The opaque pigment with the largest diameter could be obtained at the S/W ratio of 0.97 and the MAA content of 20%, as 350 nm. It gave an opacity value of 93.8% when mixed with an acrylic resin at 50% by volume. The colored opaque polymer pigments were synthesized by adding copper phthalocyanine into the monomer mixture. The addition of 2% copper phthalocyanine yielded a green-blue color but 3% yielded blue color. The latter yielded a change in the lightness (ΔL*) by a value of −31.49, and a total color difference (ΔE*) of 30.05 compared with that of white opaque polymer pigment. POLYM. ENG. SCI., 57:913–920, 2017. © 2016 Society of Plastics Engineers

Copolymeric hexyl acrylate-methacrylic acid microspheres – surface vs. bulk reactive carboxyl groups. Coulometric and colorimetric determination and analytical applications for heterogeneous microtitration

Copolymeric acrylate microspheres were prepared from hexyl acrylate using different amounts of methacrylic acid, resulting in a series of microspheres of gradually changing properties. The distribution of carboxyl groups – between surface and bulk of microspheres was evaluated. Bulk reactive carboxyl groups were determined using reverse coulometric titration with H+ ions, following hydroxide ions have been generated and allowed to react with microspheres in the first step. It was found that the number of reactive carboxyl groups available in copolymeric microspheres is lower compared to number of methacrylic acid units used for polymerization process. Moreover, there is correlation between the number of groups introduced and found to be reactive in microspheres. On the other hand, the number of surface reactive groups was proportional to the number of groups introduced in course of polymerization. Thus, the surface reactive groups can be used as reagent, in novel heterogeneous microtitration procedure, in which a constant number of microspheres of different carboxyl groups contents is introduced to the sample to react with the analyte. The applicability of novel proposed method was tested on the example of Ni2+ determination.

Methacrylic acid-co-butylmethacrylate copolymers: design, characterization and evaluation as encapsulating material for colon targeted formulations

Hydrophilic monomer methacrylic acid was copolymerized with hydrophobic monomer butylmethacrylate in different molar ratio, using AIBNfree radical initiator. Successful polymerization was confirmed by FTIR and 1H NMR, while DSC and XRD revealed the amorphous nature of the polymers. Copolymers were highly hemocompatible. The polymers showed pH-dependent swelling and erosion which increased with increase in pH. As the amount of methacrylic acid increased, the swelling and erosion also increased. Polymers were used for the microencapsulation of a model anti-inflammatory drug, aceclofenac by an oil-in-oil solvent evaporation method. Microparticles were characterized using FTIR, XRD, DSC, and SEM analysis. The negatively charged particles were almost spherical in shape. The drug release was best explained by zero-order kinetics with anomalous release mechanism. Less than 1% of drug was released at pH 1.2 while the bulk of the drug load was released at pH 6.8 or above, confirming the colon-targeting nature. The microparticles showed significant lowering in myeloperoxidase activity in trinitrobenzene sulfonic acid-induced colitis rat model. There was a significant lowering in the severity of disease symptoms and colon-to-body weight ratio. The histopathological studies also confirmed successful treatment with microparticle formulation.

The Preparation and Characterization of Redispersible Polymer Powder with Core-Shell Structure

Acrylate polymer emulsion was synthesized by semi-continuous seeded emulsion polymerization with methacrylic acid (MAA) as the hydrophilic shell monomer. The redispersible polymer powder was prepared by spray drying method. The effects of the amount of MAA, styrene (St) stoichiometry equivalents to methyl methacrylate, and two kinds of spray drying methods on size distribution of the redispersible polymer powder were further systematically investigated. The Malvern laser particle size analyzer, transition electron microscopy (TEM), scanning electron microscopy (SEM) and differential scanning calorimeter were employed to characterize the redispersible polymer powder. Results showed that the redispersible polymer powder obtained by pneumatic spray drying with excellent re-dispersibility could be synthesized at 10 % of MAA, 50 % of St stoichiometry equivalents. The final copolymer emulsion with “perfect” core-shell morphology was approved by TEM, and the comparable film forming ability of the redispersible polymer powder with the original emulsion was observed by SEM, which could form a dense and smooth membrane.

Synthesis and Surface Properties of SiO<sub>2</sub> Modified Fluorosilicone Acrylic Copolymer Hybrids

SiO2 modified fluorosilicone acrylic copolymer hybrids were synthesized via seeding emulsion polymerization in the presence of conventional nonionic and anionic surfactants, in which methyl methacrylate (MMA) and butyl acrylate (BA) were used as main monomers, small amount of methacrylic acid (MAA) and 2-hydroxyethyl methacrylate (HEMA) were used as functional monomers to confer adhesion, hardness and strength upon the latex film, while trifluoroethyl methacrylate (TFMA) and vinyl triethoxy silane (VTES) were used as fluorine- and silicon- containing monomers respectively. Meanwhile, tetraethoxysilane (TEOS) used as the precursor to prepare in-situ SiO2 nanoparticles, was added during the polymerization process, which resulted in SiO2 enhanced fluorosilicone acrylic copolymer latexes. SiO2 nanoparticles were produced in-situ during the polymerization. The nanocomposite latex film revealed better thermal resistance and wear resistance properties as compared with the counterpart free of SiO2 nanoparticles prepared under similar polymerization conditions.

The synthesis and characterization of lanthanide-encoded poly(styrene-co-methacrylic acid) microspheres

Lanthanide-encoded polystyrene microspheres with methacrylic acid (MAA) as a co-monomer and with diameters on the order of 2 μm and a very narrow size distribution were synthesized by two-stage dispersion polymerization (2-DisP). These microspheres were designed as a platform for mass cytometry-based bioassays. Different lanthanides (Ln) were loaded into these microspheres during the synthesis, through the addition of LnCl3 salts and excess MAA to the reaction after about 10% conversion of styrene, i.e., well after the microsphere nucleation stage was complete. Different levels of MAA were employed to investigate the relationship between the number of carboxyl group on the particle surface and the amount of MAA used. The reaction remained well controlled with both 2 and 4 wt % MAA. As monitored by inductively coupled plasma (ICP) mass spectrometry, we found high incorporation efficiency (>95%) of Ln ions into the particles when the total amount of LnCl3 salts in the reaction mixture was sufficiently small. The Ln incorporation efficiency decreased with the increasing amount of LnCl3 salts. Mass cytometry analysis shows that individual microspheres contain ca. 105–108 chelated lanthanide ions, either a single element or a mixture of elements. This method of incorporating lanthanide into P(S-MAA) particles through the second stage of two-stage dispersion polymerization yields microspheres suitable for the highly multiplexed detection of biomolecules.

Hyaluronic acid as an internal wetting agent in model DMAA/TRIS contact lenses

Model silicone hydrogel contact lenses, comprised of N,N-dimethylacrylamide and methacryloxypropyltris (trimethylsiloxy) silane, were fabricated and hyaluronic acid (HA) was incorporated as an internal wetting agent using a dendrimer-based method. HA and dendrimers were loaded into the silicone hydrogels and cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry. The presence and location of HA in the hydrogels was confirmed using X-ray photoelectron spectroscopy and confocal laser scanning microscopy, respectively. The effects of the presence of HA on the silicone hydrogels on hydrophilicity, swelling behavior, transparency, and lysozyme sorption and denaturation were evaluated. The results showed that HA increased the hydrophilicity and the equilibrium water content of the hydrogels without affecting transparency. HA also significantly decreased the amount of lysozyme sorption (p < 0.002). HA had no effect on lysozyme denaturation in hydrogels containing 0% and 1.7% methacrylic acid (MAA) (by weight) but when the amount of MAA was increased to 5%, the level of lysozyme denaturation was significantly lower compared to control materials. These results suggest that HA has great potential to be used as a wetting agent in silicone hydrogel contact lenses to improve wettability and to decrease lysozyme sorption and denaturation.

Investigation of Hydrogen Bonded Interpolymer Complexes Based on Poly (n‐butyl methacrylate–co‐methacrylic acid) and Poly (n‐butyl methacrylate ‐co‐4‐vinyl pyridine). Temperature Effect

AbstractSummary: Two kinds of interpolymer complexes as soluble or precipitate of different structures were obtained in both THF and butan‐2‐one as common solvents by monitoring the hydrogen‐bonding density within homoblends of poly(n‐butyl methacrylate‐co‐4‐vinylpyridine) (BM4VP) and poly(n‐butyl methacrylate‐co‐methacrylic acid) (BMMA). A viscometry study confirmed such differences between these two types of interpolymer complexes from the behavior of the reduced viscosity of their blend solutions with feed blend composition. Qualitative and quantitative analyses of the interactions that occurred between these copolymers of relatively bulky side chain length containing various amounts of methacrylic acid and 4‐vinylpyridine were carried out by FTIR. The fraction of associated pyridine groups to the carboxylic groups of the BMMA increases as the content of these latter increases in the BMMA/BM4VP blends. The obtained results also showed that the fractions of associated pyridine within the BMMA25/BM4VP26 blends are higher than those within BMMA18/BM4VP19 or BMMA8/BM4VP10. The FTIR analysis of a selected BMMA18/BM4VP19 1:1 ratio, carried out from 80 °C to 160 °C, above the glass transition temperatures of the two constituents of the blend, confirms the presence of strong hydrogen bonding interactions between the pyridine and the carboxylic groups within these blends even at 160 °C. A LCST is expected to occur at higher temperature as shown from the progressive decrease of the fraction of the associated pyridine.

PH-responsive hydrogel microparticles as intelligent delivery carriers for α-MSH antagonists

For a first step in the development of an intelligent delivery system for a nonapeptide as an α-MSH antagonist, pH-responsive P(MAA-co-EGMA) hydrogel microparticles were prepared and their feasibility as intelligent delivery carriers was evaluated. There was a drastic change in the swelling ratio of P(MAA-co-EGMA) microparticles at a pH of around 5 and as the MAA amount in the hydrogel increased, the swelling ratio increased at a pH above 5. The loading efficiency of the nonapeptide at pH 7 increased with the amount of Methacrylic acid (MAA) in the hydrogel and at pH 2, where the electrostatic attraction was greatest, a high loading efficiency was not obtained because of the low swelling ratio of the hydrogel. The P(MAA-co-EGMA) microparticles demonstrated a pH-sensitive release behavior for the nonapeptide. In addition, the P(MAA-co-EGMA) microparticles showed a protective ability for the nonapeptide and preserved the stability of the nonapeptide. © 2010 American Institute of Chemical Engineers AIChE J, 2010

Removal of basic dyes from aqueous medium using novel poly(MAA)-cross linked pregelled starch graft copolymer

Wastewater from textile industries may contain a variety of dyes that have to be removed before their discharge into waterways. For this purpose, pregelled starch (PG) as one of the most abundant biodegradable carbohydrate polymer was first cross linked with epichlorohydrin to obtain insoluble cross-linked pregelled starch (CPS). The latter was graft copolymerized with different amounts of methacrylic acid (MAA) using potassium persulphate as initiator. This was done to obtain six levels of poly(MAA)-cross linked pregelled starch graft copolymers (PMCPS) having different graft yields (expressed as meq COOH/100 g starch) with increasing order and designated as (PMCPS 1 to PMCPS 6). The latter copolymers were used to remove basic dyes namely (safranine T, methylene blue, crystal violet) from their solution and filtered to form polymer—dyes complex. Major factors affecting the dyes removal such as dye concentration, pH, polymer dose, treatment time, agitation speed, and extent of grafting were studied in detail. It was found from the obtained results that; the % dye removal increased by (a) increasing the dye concentration and pH within the range studied; (b) increasing the agitation speed until ≥ 40 rpm then leveled off thereafter; (c) increasing the polymer dosage from 0.25 to 3.0 g/L then leveled off thereafter; (c) increasing the time of the reaction up to 60 minute then leveled off after that; and (d) increasing the extent of grafting of PMCPS i.e., from PMCPS 1 to PMCPS 6. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Influences of MAA on the porous morphology of P(St–MAA) latex particles produced by batch soap-free emulsion polymerization followed by stepwise alkali/acid post-treatment

Soap-free P(St–MAA) latex particles with variable styrene (St)/methacrylic acid (MAA) ratio were synthesized by batch emulsion copolymerization at 70 °C for 7 h, and the particles with porous structure were obtained after stepwise alkali/acid post-treatment. The effects of MAA amount on the particle morphologies after the alkali and the stepwise alkali/acid post-treatments were investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Results indicated that the alkali-treated latex particles showed anomalous structure with rough surface, and no hollow was clearly identified inside them. When these alkali-treated particles were further treated with acid solution, the particle surface became much smoother, and porous morphology appeared. It was found that when the MAA amount was less than or equal to 4 mol%, no obvious morphological variation was observed; while the latex particles showed clearly porous structure as the MAA amount increased to 6 mol%; with the further increase of MAA amount to 8 mol%, the pore size decreased distinctly.

Influencing Mechanism of Methacrylic Acid on the Redispersion Properties of Redispersible Polymer Powders

Acrylic polymer emulsions were synthesized by semi-continuous seeded emulsion polymerization and the corresponding redispersible polymer powders were prepared by spray drying. Methacrylic acid (MAA) was used as the hydrophilic shell monomer. The influences of the amount of MAA on the average particle size of the original emulsion, the dispersion stability, zeta potential, and size distribution of the redispersion emulsion were investigated. The results show that with an increase in the amount of MAA, the particle size of original emulsion, the dispersion stability, and the zeta potential of the redispersion emulsion increased significantly. The size distribution of the redispersion emulsion with a high amount of MAA was unimodal and similar to the original emulsion indicating excellent water-redispersibility. Transmission electron microscopy (TEM) was used to characterize the internal microtopography of the redispersible polymer powder, and results showed that with a higher amount of MAA, millipores with larger pore sizes were present in the transection of the redispersible polymer powder. When polymer powders are redispersed in an aqueous phase, large micropores provide a more convenient channel for water permeation, which optimizes the redispersibility. The hairy structure and higher zeta potential endow the redispersion emulsion with excellent redispersion stability.

A study on the characteristic of normoxic polymer gel dosimeter according to its composition

In this study, to find the optimal composition of the gel as therapeutic radiation, the amounts of methacrylic acid and gelatin were varied. The polymer gel with various compositions were evaluated for its sensitivity, reproducibility, and accuracy. As the concentration of the gelatine is high, the threshold R2 value increases and the dose response was decreases. As the concentration of the methacrylic acid is high, both the threshold R2 value and the dose response were decrease. As both concentrations of the gelatine and the methacrylic acid is high, the sensitivity to the dose was increases within some range. It was found that the polymer gel composed in this study can be optimized for measuring the therapeutic radiation.

Preparation of poly (MAA)‐crosslinked pregelled starch graft copolymer and its application in waste water treatments

AbstractPropelled starch (PG) was first crosslinked with epichlorohydrin to obtain insoluble crosslinked pregelled starch (CPS). The latter was graft copolymerized with different amounts of Methacrylic acid using potassium persulphate as initiator. This was done to obtain six levels of poly (MAA)‐crosslinked pregelled starch graft copolymers (PMCPS) having different graft yields (expressed as meq COOH/100 g starch) with increasing order and designated as (PMCPS 1 to PMCPS 6). The latter copolymers were dispersed in aqueous solution of heavy metal ions (Cu2+, Pb2+, Cd2+, and Hg2+) and filtered to form polymer‐metal ions complex. Different factors affecting the heavy metal ions removal such as pH, extent of grafting, treatment time and starch dose were studied in detail. It was found from the obtained results that; the residual metal ions removal from their aqueous solutions increased with (a) increasing the extent of grafting of PMCPS i.e., from PMCPS 1 to PMCPS 6; (b) Increasing the pH of the metal ions solution complex from 1 to 8; (c) increasing the starch dosage from 0.25 to 2.0% (W/V), then leveled off thereafter, (d) increasing the time of the reaction up to 20 min then leveled off after that. On the other hand, Pb, Cd and Hg ions were also removed from their solutions with different extent. Furthermore, the prepared copolymer could be recovered by washing the metal ions from the complex with weak acid 1N HNO3 (pH 2) and the metal‐binding activity of the starch was slightly reduced by this process. Finally, the ability of PMCPS to remove three types of basic dyes from their solutions was also reported. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009