Journal articles: 'Methacrylic copolymer' – Grafiati (2024)

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Sedimentation of water dispersed systems of acrylate copolymers in xylene Methyl methacrylate - butyl acrylate - methacrylic acid copolymer and butyl methacrylate - methacrylic acid amide copolymer of a different segmental structure were stabilised with non-ionic and anionic surfactants. Gel chromatography, viscosimetry, tensiometry, conductometry and sedimentation methods were applied to define the properties of the synthesized copolymers, surfactants in water solutions and water dispersions. The types and the properties of the phases being in a state of sedimentation balance were also determined. The obtained experimental data were interpreted and justified by using the copolymer and surfactants properties. The existing correlations were pointed out. The obtained results show that the stability of a disperse system considerably depends on the structure of the copolymer. The MMA/BA/MAA copolymer has monomeric units of elastic butyl acrylate. Segments containing these monomeric units adsorb surfactants much better and form more stable water disperse systems. However, the MBA/AMAA copolymer with the polarity of amide group of methacrylamide makes disperse systems less stable.

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Methacrylic acid copolymers crosslinked with 0.25-16 % divinylbenzene were synthesized by free radical polymerization using benzoyl peroxide as an initiator. The products were washed, dried and passed through a 80-mesh sieve prior to determining their infrared spectra, swelling capacity in water and disintegrant efficacy for microcrystalline cellulose (MCC) placebo tablet. The crosslinked methacrylic acid and divinylbenzene copolymers were successfully prepared as indicated by IR spectra, yielding around 50-80 %. The sieved particles of copolymers were white to faint yellow. In contact with water, they hydrated and swelled, where their swelling capacity was lowered with increasing the level of crosslink (divinylbenzene) in the copolymer structure. The copolymer with 0.25 % crosslink caused the MCC tablet to disintegrate fastest (1.2 min), corresponding to its highest swelling capacity. The disintegration efficacy increased with an increase in copolymer concentrations, but decreased with an increase in compression forces.

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The parameters of light resistance, heat resistance and water absorption of organic glasses based on methyl methacrylate copolymers with various methacrylic monomers containing UV absorbers and UV stabilizers are investigated. It has been shown that UV stabilizers - quenchers of excited states: diphenyl and isomers of terphenyl have the best stabilizing eff ect. A decrease in water absorption of copolymer organic glasses with the introduction of cyclic fragments into the copolymer was established. It was shown that the introduction of methyl methacrylate - methacrylic acid into the system as a comonomer of cyclohexylmaleimide allows increasing the heat resistance of organic glasses.

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The application of polymers for controlled drug delivery is influenced by no toxicity and solubility in different pH mediums. There already are existing pharmaceutical medicaments based on aqueous dispersion of an anionic copolymer methyl acrylate, methyl methacrylate and methacrylic acid. The aim of this work was to synthesise copolymers of methyl methacrylate and methacrylic acid and to estimate the effects of monomers ratio (1:1 and 1:2) on the molecular mass, polydispersity index, and solubility of obtained polymers. Acetone was used as a solvent because both monomers and the initiator azobisisobutyronitrile are soluble in it. FTIR method was used for functional group characterization, the gel permeation chromatography method for average molecular weights and the distribution of molecular weights determinations. High pressure liquid chromatography (HPLC) was applied for the estimation of residual monomers in obtained copolymers. The titration with ethanol solution of NaOH was used for assessing of monomer units in copolymers. The copolymer with the molar ratio of monomers 1:1 was soluble in water bufer with pH values higher then 6, while the copolymer with the molar ratio of monomers 1:2 was soluble in bufer with pH higher then 9.

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The aggregation behavior of un-neutralized, partly and fully Na-neutralized poly(styrene-ranmethacrylic acid) copolymers in aqueous solution was investigated using a SEM technique. It was observed that the un-neutralized copolymer formed spherical particles on the Si wafer, and the average size of particles was ca. 160 nm. The particle sizes did not change much with acid content. Upon the neutralization of the acid groups of the copolymer with NaOH, the copolymer became more hydrophilic, leading to the formation of network-like feature consisting of much smaller particles (<50 nm), compared to those of the acid copolymers. With increasing ionization, the boundary of the particles forming networks faded away, implying the formation of tubular structures.

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The behavior of methacrylic copolymers with oligoethylene glycol and amine groups in aqueous solutions has been studied. The eff ect of the composition of copolymers of alkoxyoligo(ethylene glycol) methacrylates and N-[3-(dimethylamino) propyl] methacrylamide on their solubility in aqueous media, aggregation properties and surface activity at the water-oil phase boundary was demonstrated. The presence of thermo- and pH-responsive properties, characterized by lower critical solution temperature, has been shown. Polymers exhibit high interfacial activity at the water-toluene interface, which increases with an increase in the proportion of methacrylic ether units in the copolymer. For polymers in aqueous media the value of the critical micelle concentration was found in the region of 10-3 g/L.

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Microcapsules containingn-octadecane (MicroC18) withn-octadecyl methacrylate (ODMA)-methacrylic acid (MAA) copolymer shell were fabricated through phase separation method, in which the shell-forming copolymers synthesized by free-radical solution polymerization. Meanwhile, theses copolymers were employed as the surfactant during microencapsulation. The crystallization temperature and crystallinity degree of comb-like copolymer display a gradual decrease with an increase the molar ratio of MAA. MicroC18 with spherical profiles and the diameter ranging from 3 to 20 μm were fabricated. In addition, the system pH value plays an important role in the formation process of microcapsules and the optimum value of pH in the range of 8.5-10.5.

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Results from the x-ray photoelectron spectroscopy (XPS or ESCA), ion scattering spectroscopy (ISS or LEIS), and Fourier transform infrared spectrometry (FTIR) analyses are presented for unmodified and modified poly (methylmethacrylate)/poly (methacrylic acid) (PMMA/PMAA) copolymer films. Analyses of the unmodified PMMA/PMAA copolymer series, via ESCA, ISS, and FTIR, established the surface composition and functionality of the PMMA/PMAA copolymers before the H2O/Ar rf-plasma treatment was employed. The ESCA, ISS, and FTIR analysis of these modified PMMA/PMAA copolymers show that surface modification over a limited depth (50–200 Å) has occurred. The composition, bonding, and functionality changes of the surfaces are discussed. A two-step modification mechanism (surface reduction of the PMMA/PMAA copolymer followed by H2O adsorption) is proposed to interpret the spectroscopic results.

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Micellization of di- and triblock copolymers, poly(methacrylic acid)-block-polystyrene and poly(methacrylic acid)-block-polystyrene-block-poly(methacrylic acid), varying in molecular weight and composition, has been studied by static and dynamic light scattering, and sedimentation velocity. Micelles with polystyrene cores were prepared in water-dioxane mixtures, rich in dioxane, and transferred into water-rich mixtures, water, and aqueous buffers via stepwise dialysis. It has been shown that, in dioxane-rich mixtures, the micellar system was in dynamic equilibrium, while in water-rich solvents, water, and aqueous buffers the micellization equilibrium was frozen and micelles behaved like autonomus particles. Under certain conditions, micelles were accompanied by independent large particles. This phenomenon, known from other micellar systems as an "anomalous micellization", is discussed.

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In this paper the biodegradation study of grafted copolymers of polystyrene (PS) and corn starch and poly(methacrylic acid) and corn starch in model river water is described. These copolymers were obtained in the presence of different amine activators. The synthesized copolymers and products of degradation were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Biodegradation was monitored by mass decrease and number of microorganisms by Koch?s method. Biodegradation of both copolymers advanced with time, poly(methacrylic acid)-graft-starch copolymers completely degraded after 21 day, and polystyrene-graft-starch partially degraded (45.78-93.09 % of total mass) after 27 days. Differences in the degree of biodegradation are consequences of different structure of the samples, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. The grafting degree of PS necessary to prevent biodegradation was 54 %. Based on experimental evidence, mechanisms of both biodegradation processes are proposed, and influence of degree of starch and synthetic component of copolymers on degradation were established.

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A method for the synthesis of dicinamyl ester of 2,5-furandicarboxylic acid (DCF) a new unsaturated compound of the furan series and potential monomer for producing copolymers with various vinyl compounds and based on them a new generation of construction and ion-exchange materials has been developed. DCF does not form hom*opolymers as in bulk as in solution (toluene solvent). However, DCF is actively copolymerized with styrene, methyl methacrylate, methacrylic and acrylic acids to form cross-linked polymers with varying degrees of crosslinking. The copolymerization constants of DCF with all investigated vinyl compounds were determined. The DCF copolymers are enriched with comonomer units for all ratios of the components in the initial reaction mixture. They are statistical, and the comonomer units in the macromolecule are randomly arranged. Copolymers with styrene or methyl methacrylate have higher mechanical strength compared to polystyrene and polymethyl methacrylate. Copolymers containing carboxyl groups and 10-20 % wt. crosslinking agent exhibit good ion-exchange properties with respect to heavy metals. The equilibrium adsorption amount of Cu2+ onto ion-exchange сopolymers (221-234 mg/g) was almost twice as large as that onto Amberlite IRC-748 (120.0 mg/g). Materials with a crosslinking agent content of 2.5-5% wt. form polymer gels with high water absorption. Materials containing 2.5 % wt. crosslinking agent (≥ 1400 % for copolymer DCF /acrylic acid and ≥ 1700 for copolymer DCF/methacrylic acid) are showed maximum swelling. These materials can be recommended as water absorbers.

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Konjac glucomannan is a kind of natural polysaccharides with excellent biocompatibility and biodegradable activities. In this paper, a series of Konjac glucomannan-graft-methacrylic acid copolymers were prepared by the free-radical initiation grafting Konjac Glucomannan (KGM) with methacrylic acid(MA). The reaction conditions such as reaction temperature, KGM and MA ratio and initiator concentration, were investigated, and chemistry of KGM and its MA grafted copolymers were characterized using FTIR.

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The synthesis of novel copolymers using one-step reversible addition-fragmentation chain transfer (RAFT) copolymerization of biocompatible methacrylic acid (MAA), lauryl methacrylate (LMA), and difunctional ethylene glycol dimethacrylate (EGDMA) as a branching agent is reported. The obtained amphiphilic hyperbranched H-P(MAA-co-LMA) copolymers are molecularly characterized by size exclusion chromatography (SEC), FTIR, and 1H-NMR spectroscopy, and subsequently investigated in terms of their self-assembly behavior in aqueous media. The formation of nanoaggregates of varying size, mass, and hom*ogeneity, depending on the copolymer composition and solution conditions such as concentration or pH variation, is demonstrated by light scattering and spectroscopic techniques. Furthermore, drug encapsulation properties are studied by incorporating the low bioavailability drug, curcumin, in the nano-aggregate hydrophobic domains, which can also act as a bioimaging agent. The interaction of polyelectrolyte MAA units with model proteins is described to examine protein complexation capacity relevant to enzyme immobilization strategies, as well as explore copolymer self-assembly in simulated physiological media. The results confirm that these copolymer nanosystems could provide competent biocarriers for imaging and drug or protein delivery/enzyme immobilization applications.

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Implantation of drug releasing coronary stents has been developed as an useful method for prevention of the restenosis in blood vessels. Copolymers of methyl methacrylate (MMA), butyl methacrylate (BMA) and methacrylic acid (MAA) were prepared as the coating polymer for drug releasing stent. The adhesion of the polymer with metal substrate and the biocompatibility were studied. Effect of the polymer composition on the adhesion between polymer coatings and metal substrate, as well as the effect of the polymer purification method on biocompatibility of the polymer, was studied. The results showed that the copolymer coating has good dry and wet adhesion properties, which can be improved by control of the polymer compositions. Biocompatibility of the prepared copolymer comes within the permission limit.

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No anomalies were observed during the measurement of sedimentation coefficients of block copolymer micelles formed by copolymers of styrene and methacrylic acid in a mixed solvent; 80 vol.% of dioxane and 20 vol.% of water. The shapes of the sedimenting boundaries suggest that the size heterogeneity of the micelles is small. Linear relations between 1/s and c were obtained. The value of the hydrodynamic coefficient κ was between 2 and 4 in a good agreement with the value 2.75 or 2.86 that was obtained by combining Burgers' or Fixman's values of the coefficient of the concentration dependence kvs for hard spheres with Einstein's value of [η] for spheres.

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The influence of the concentration of finely dispersed aluminum and compatibilizer on the resistance to peeling of aluminum foil from the surface of a composite based on low density polyethylene and high density polyethylene is considered. To improve the compatibility of the filler with the polymer matrix, a compatibilizer was used, which is a graft copolymer of polyethylene of various grades with methacrylic acid and maleic anhydride. Copper and aluminum foil was used as a substrate. It is shown that the introduction of a compatibilizer into the composition of aluminum-filled composites improves their peeling resistance. It has been found that if an aluminum filled compatibilizer is used directly as an adhesive, then the peeling resistance of copper and aluminum foil is significantly increased. Graft copolymers of polyethylene with maleic anhydride have the highest peel resistance values. The results of the study of the influence of the pressing temperature on the type of adhesive failure are presented. It is shown that with an increase in the pressing temperature, a mixed type of adhesive destruction is observed. It has been experimentally proved that, in percentage terms, the cohesive type of fracture prevails in composites where graft copolymers are used as a polymer matrix. It was found that a 100 % cohesive type of fracture is observed in foil-clad composites pressed at a temperature of 190 °C, where a graft copolymer of polyethylene with methacrylic acid or maleic anhydride is used as an adhesive.

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A novel copolymer derived from tamarind kernel polysaccharide (TKP) and poly(methacrylic) acid (g-TKP/pMA) has been successfully synthesised through surface initiated atom transfer radical polymerization (SI-ATRP).

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Hybrid Langmuir and Langmuir-Blodgett monolayers of a perfluorooctadecanoic acid mixed with a rigid block copolymer, poly(3,5-bis(3,5-bis(benzyloxy)benzyloxy)benzyl methacrylate-random-methacrylic acid)-block-poly(2-perfluorooctylethyl acrylate), which is composed of benzyloxy dendron side chains and perfluorinated side chains, were prepared and characterized by surface pressure–surface area isotherms, atomic force microscopic images and neutron and X-ray reflectometries. The two-dimensionally phase-separated structures of monolayer films and their morphologies with plateau and terrace were confirmed. The monolayers were separated into a dendron layer, a perfluorinated layer, and a carboxyl layer. The layer formation is originated not only in the intermolecular interaction between a perfluorooctadecanoic acid and a block copolymer but also in the geometry of the molecules. Especially, the amphiphilicity of perfluorinated surfactant plays a role to the ordered array of the block copolymers.

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Gamma irradiation effects on methyl methacrylate (MMA) – methacrylic acid (MAA) copolymer were investigated by spectroscopic (ESR, FTIR) and thermal (DSC) methods. Electron spin resonance (ESR) spectra of the irradiated copolymer are analysed to be caused by different component spectra from the free radicals (~ CH2 – CH – CH2 ~ and – COOH or – COOCH3) as per computer simulation analysis. The ESR signals could be annealed near the transition temperature of the copolymer, and the free radicals formed irradiation might react to form stable structures at transition temperatures. Fourier transform infrared (FTIR) studies suggested that the 3380 cm-1 absorption band (due to COOH groups and or hydrogen bonding) and 1734 cm-1 absorption band (due to carbonyl groups) were mostly affected by irradiation. Differential scanning calorimeter (DSC) thermogram indicated that the copolymer is a two-phase system (PMMA and PMAA), and transition temperatures are influenced by gamma irradiation. The dosimetric application of copolymer is tested by the ESR technique, and it was found suitable for dosimetry.

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Thermal performance of copolymer based on polyethylene glycol fumarate and methacrylic acid in a dynamic mode, in an inert nitrogen environment are considered in the present work. Kinetic evaluation of thermal decomposition process was conducted using three different data processing methods (Friedman, Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose). Utilizing a mixed-method approach kinetic triplets Eа, A, g(a) were received. The received kinetic parameters were used to calculate the thermodynamic characteristics of Gibbs energy (∆G), enthalpy (∆H) and entropy of activation (∆S). Copolymer thermal gravimetric analysis (TGA) and differential thermogravimetric analysis (DTA) curves were studied under nitrogen environment using a heating rate of 2,5, 5, 10 or 20°C/min. The method of Invariant Kinetic Parameters was used to identify the reaction model and pre-exponential factor. The main phase of copolymer decomposition was set, which occurred within a narrow temperature interval and is evidenced by the spike on the differential curve. Values for 13 reaction models were received. Utilised methods resulted in a proper energy activation alignment within 223-229 kJ mol-1. Design and experimental data provided close values. TGA and DTA curve analysis has shown a sufficient thermal stability of these copolymers under the nitrogen environment.

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RAFT aqueous dispersion polymerization is used to prepare poly(methacrylic acid)-poly(2-hydroxypropyl methacrylate) diblock copolymer nanoparticles, which exhibit stimulus-responsive behaviour on adjusting the solution temperature and/or solution pH.

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Gastro-resistant capsules are often used for several purposes, such as protection of unstable drugs in acid medium to the action of gastric fluids or protection of the gastric mucosa to irritants drugs. The aim of this study was to verify the variation of preparations of capsules coating with cellulose acetate phthalate and methacrylic acid copolymer, without drug addition, in 7-10% coating concentrations, prepared manually with four or five immersions in tested coating solution. Results were analyzed considering the formulation’s disintegration test. Within the context of formulations under analysis, it was observed that the capsules coated with cellulose acetate phthalate 10% complied with the pharmacopeia’s disintegration specifications. However, capsules coated with methacrylic acid copolymer did not show accordance with the pharmacopeia’s specifications. The results emphasize the need for the standardization of coating methodology.

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The objective of the present study was to prepare a novel mixed functional cationic exchange copolymer microsphere containing methyl methacrylic acid and sulfonated styrene crosslinked with divinylbenzene. The emulsion polymerization was used to prepare the cationic exchange copolymer microsphere which was characterized by the scanning electron micrograph (SEM) and the fourier transform infrared spectroscopy (FTIR). The release characteristic of the loaded drug i.e. dextromethorphan hydrobromide from the copolymer microsphere was studied under both simulated gastric (pH 1.2) and intestinal (pH 6.8) conditions. The result showed that the drug released from the novel copolymer microsphere depended on the pH of the release media.

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The polyanion of copolymer poly (2-methacryloyloxyethyl phosphorylcholine-co-methacrylic acid) (PMA30) was synthesized by free radical polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid (MA). The synthesized PMA30 was assembled on chitosan (CS) surfaces formation of chitosan nanoparticles by polyionic complex. The chitosan nanoparticle was prepared using methacrylic acid (MA), 2-methacryloyloxyethyl phosphorylcholine (MPC) by template polymerization. The size distribution and structure properties of chitosan nanoparticles were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), transmission electron microscopy (TEM) and zeta potential. These results show that a cell outer membrane mimetic surface was formed on the chitosan nanoparticles, which provides an effective way to improve the biocompatibility of chitosan nanoparticles.

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An ethylene-methacrylic acid copolymer, formulated by BASF as a waterborne suspension of its alkylammonium salt and used, among other applications, in art conservation as a temporary protective coating was characterized using Fourier transform infrared (FT-IR) spectroscopy aided by modulated differential scanning calorimetry (MDSC) and ellipsometry. The thermal conversion of thin copolymer films from the freshly applied state, where carboxylic acid and carboxylate ion functional groups co-exist, to a purely acidic working state was spectroscopically followed. Transmission mid-infrared data of the working state showed a 1 : 12 ratio of methacrylic acid towards ethylene units. The glass transition temperature ( Tg) in the same state was found at 45 °C. Copolymer films spin-coated on mechanically polished bronze and iron coupons were characterized with transflection infrared spectroscopy and compared to corresponding transmission mid-infrared spectra of copolymer films spin-coated on silicon wafers. In the case of bronze coupons, evidence for interaction of the carboxylate ion with the copper substrate was obtained. The chemical structure and the thermal behavior of the coating, as well as some implications on its protective capability towards iron and copper alloys, is discussed as this material has received considerable attention in the field of metal conservation and coatings.

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Abstract Pure and VO2+ doped methacrylic acid ethylacrylate (MAA:EA) copolymer films were prepared by using a solution casting method. Various techniques including X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, scanning electron microscopy and electron paramagnetic resonance were employed for characterization of the samples. XRD patterns showed some degree of crystallinity of the doped polymer films due to interaction of the MAA:EA copolymer with VO2+. FT-IR spectral studies of pure and VO2+ doped MAA:EA copolymer films displayed significant structural changes within the doped copolymer film indicating the complexation. The optical absorbance of the pure and VO2+ doped films were measured in the 200 nm to 800 nm wavelength range. The values of the absorption edge and indirect band gaps were calculated. The optical band gap decreased with the increase of mol% of VO2+. From the EPR spectra, the spin- Hamiltonian parameters (g and A) were evaluated. The values of the spin-Hamiltonian parameters confirmed that the vanadyl ions were present in MAA:EA copolymer films as VO2+ molecular ions in an octahedral site with a tetragonal compression (C4v). The morphology of the copolymer samples was examined by scanning electron microscopy. The enhanced crystalline nature of the doped copolymer was identified from SEM analysis.

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In order to investigate the feasibility of using methacrylic acid (MAA)-styrene (St) copolymer as dispersants to disperse azoxystrobin particles in aqueous suspension, the adsorption kinetics, isotherm and thermodynamics of MAA-St copolymer onto azoxystrobin particle surfaces were studied by batch equilibrium experiments. The results showed that the adsorption process followed the pseudo-second-order kinetic model with the entire adsorption, adsorption rate decreased with the initial concentration of MAA-St copolymer increasing. The equilibrium data were fitted with Langmuir isotherm equation better. The thermodynamic parameters were calculated, which indicated that the adsorption was a spontaneous and exothermic process in nature, and higher temperature is not beneficial to that adsorption process.

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A self-assembled poly(methacrylic acid)–poly(ε-caprolactone) block copolymer with a disulfide linkage, PMAA-b-PCL-SS-PCL-b-PMAA, was synthesized for enhanced cellular uptake due to a reduction response to GSH and pH-sensitive characteristics.

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Polymerization was carried out using the method of radiation initiation. Experiments were carried out on methacrylic acid derivatives with bulky substituents (isodecyl and benzyl). The regularities of its formation are investigated. The conditions for obtaining a hom*ogeneous copolymer are determined. A polymer with a molecular weight of more than 106 g/mol was obtained. An increase in the viscosity of the copolymer with an increase in the temperature of the solution was shown.

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We demonstrate an electrospray/electrospinning process to fabricate stimuli-responsive nanofibers or particles that can be utilized as stimuli-responsive drug-loaded materials. A series of random copolymers consisting of hydrophobic ferrocene monomers and hydrophilic carboxyl groups, namely poly(ferrocenylmethyl methacrylate-r-methacrylic acid) [poly(FMMA-r-MA)] with varied composition, was synthesized with free radical copolymerization. The morphologies of the resulting objects created by electrospray/electrospinning of the poly(FMMA-r-MA) solutions were effectively varied from particulate to fibrous structures by control of the composition, suggesting that the morphology of electrosprayed/electrospun copolymer objects was governed by its composition and hence, interaction with the solvent, highlighting the significance of the balance of hydrophilicity/hydrophobicity of the copolymer chain to the assembled structure. Resulting particles and nanofibers exhibited largely preserved responsiveness to reactive oxygen species (ROS) during the deposition process, opening up the potential to fabricate ROS-sensitive material with various desirable structures toward different applications.

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The latex synthesis in the presence of ethylene-propylene copolymer and methacrylic acid (MAA) was considered for this experiment. The kinetic regularities of the synthesis process were determined and the optimal quantities and ratios of the components were determined both experimentally and by mathematical modeling. It was determined that a modified latex with optimal values ​​is obtained when the amount of methacrylic acid in the latex is 5 parts by weight. The absorbent composition was prepared latex-based based on synthesized EPC – + methacrylic acid. The prepared absorbent was impregnated with viscose (22B) and 222K kapron cord and a rubber-cord bond were determined. The findings of the present study show that the aqueous dispersions of EPC latex were synthesized using various emulsifiers with high technological stability. The presence of the main factors affecting the stability and adhesive properties of the EPC aqueous dispersion has been established. It has been shown that the best stability for 6 months is achieved at a pH value of 12.EPC water emulsion was modified in the presence of MAA by graft copolymerization.

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Polymerization through reversible addition-fragmentation chain-transfer (RAFT) polymerization has been extensively employed for the production of polymers with controlled molar mass, complex architectures and copolymer composition distributions intended for biomedical and pharmaceutical applications. In the present work, RAFT miniemulsion copolymerizations of methyl methacrylate with acrylic acid and methacrylic acid were conducted to prepare hydrophilic polymer nanoparticles and compare cell uptake results after bioconjugation with bovine serum albumin (BSA), used as a model biomolecule. Obtained results indicate that the RAFT agent 2-cyano-propyl-dithiobenzoate allowed for successful free radical controlled methyl methacrylate copolymerizations and performed better when methacrylic acid was used as comonomer. Results also indicate that poly(methyl methacrylate-co-methacrylic acid) nanoparticles prepared by RAFT copolymerization and bioconjugated with BSA were exceptionally well accepted by cells, when compared to the other produced polymer nanoparticles because cellular uptake levels were much higher for particles prepared in presence of methacrylic acid, which can probably be associated to its high hydrophilicity.

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Silver nanoclusters were synthesized through one-step UV photoreduction using the multiple carboxyl copolymer poly(methacrylic acid-co-itaconic acid) as a novel template, which can be used for highly sensitive and selective detection of Cu²⁺ by fluorescence quenching.

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Stimuli-responsive water-soluble and amphiphilic polymers have attracted much attention because their micelles can be produced or destroyed by changing the temperatute, pH, ionic strength, and solvent polarity. In this work, a triply hydrophilic block copolymer of poly (ethylene glycol) and poly (methacrylic acid-co-dimethylamine ethyl methacrylate) [PEO-P(MAA-co-DMAEMA)] was synthesized and characterized. The copolymer system is believed to have the potential for drug delivery applications due to the biocompatibility of MAA and DMAEMA.

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Background: Recombinant human keratinocyte growth factor (rHuKGF) has gained considerable attention by researchers as epithelial cells proliferating agent. Moreover, intravenous truncated rHuKGF (palifermin) has been approved by Food and Drug Administration (FDA) to treat and prevent chemotherapy-induced oral mucositis and small intestine ulceration. The labile structure and short circulation time of rHuKGF in-vivo are the main obstacles that reduce the oral bioactivity and dosage of such proteins at the target site. Objective: Formulation of methacrylic acid-methyl methacrylate copolymer-coated capsules filled with chitosan nanoparticles loaded with rHuKGF for oral delivery. Methods: We report on chitosan nanoparticles (CNPs) with diameter < 200 nm, prepared by ionic gelation, loaded with rHuKGF and filled in methacrylic acid-methyl methacrylate copolymercoated capsules for oral delivery. The pharmaco*kinetic parameters were determined based on the serum levels of rHuKGF, following a single intravenous (IV) or oral dosages using a rabbit model. Furthermore, fluorescent microscope imaging was conducted to investigate the cellular uptake of the rhodamine-labelled rHuKGF-loaded nanoparticles. The proliferation effect of the formulation on FHs 74 Int cells was studied as well by MTT assay. Results: The mucoadhesive and absorption enhancement properties of chitosan and the protective effect of methacrylic acid-methyl methacrylate copolymer against rHuKGF release at the stomach, low pH, were combined to promote and ensure rHuKGF intestinal delivery and increase serum levels of rHuKGF. In addition, in-vitro studies revealed the protein bioactivity since rHuKGFloaded CNPs significantly increased the proliferation of FHs 74 Int cells. Conclusion: The study revealed that oral administration of rHuKGF–loaded CNPs in methacrylic acid-methyl methacrylate copolymer-coated capsules is practically alternative to the IV administration since the absolute bioavailability of the orally administered rHuKGF–loaded CNPs, using the rabbit as animal model, was 69%. Fluorescent microscope imaging revealed that rhodaminelabelled rHuKGF-loaded CNPs were taken up by FHs 74 Int cells, after 6 hours’ incubation time, followed by increase in the proliferation rate.

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Lavender oil- (LO-) loaded ultrafine nanoparticles (NP) ( diameter < 50 nm ) of a copolymer were used for impregnating fabrics of cotton, cotton polyester, and polyester-elastane. The copolymer was composed mainly of methyl methacrylate (MMA) units with a low proportion of methacrylic acid (MAA). Moreover, two kinds of NP were used: one containing uncrosslinked copolymer and another one composed of crosslinked material. All the fabrics impregnated with NP of uncrosslinked copolymer keep the aroma up to 25 washes. Under storage at ambient conditions, the fabrics impregnated with NP of either uncrosslinked or crosslinked copolymer emitted aroma for up to almost 60 days. The long duration of aroma emission from fabrics is attributed to ease of the small nanoparticles used in this study of penetrating and staying inside the pores of the fabric fibers.

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Fe3O4nanoparticles and poly(N-isopropylacrylamide-co-methacrylic acid) were combined to form dual-magnetic thermosensitive microspheres. The results of fourier-transform infrared (FTIR) spectroscopy, transmission electron microscope (TEM) and thermogravimetric analyzer (TGA) confirm that the microspheres are characterized with a magnetic Fe3O4core, a poly(N-isopropylacrylamide-co-methacrylic acid) shell, and an average diameter of about 150-300nm. Spectra of wide angle X-ray diffraction (WAXD) indicate that the copolymer on the surface of Fe3O4nanoparticles shows no influence on the inverse cubic spinel phase of Fe3O4. The lower critical solution temperature (LCST) of the thermosensitive copolymer-shell is about 39°Cas determined by a turbidimeter. Besides, the microspheres exhibit an obvious advantage using magnetic separation, and can be heated through an external alternating magnetic field to generate thermal effects, thus possess dual-magnetic responses (including magnetic delivery and magnetic-thermal effects). The synthesized microspheres with dual-magnetic and thermosensitive responses have potential applications in a magnetic drug-targeting delivery system for controlled drug release.

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Abstract Polymer-Polymer blends containing ethylene-methacrylic copolymers (EMAA) and polyethylene terephthalate (PET) (where PET is the minor component) have been investigated. The permeability properties and the morphology of these blends, when the polyolefin phase is mildly crosslinked with small amounts of an agent that preferentially crosslinks the ethylene copolymer was also studied. The permeability barrier properties of such polymer blends increase as the concentration of the crosslinking agents increase until excessive crosslinking takes place. The morphology of the blends – the size of the dispersed particles – change significantly as more coupling agents are used. These techniques afford us a novel technique to improve the permeability barrier properties by control of the particle size of the barrier polymer.

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Abstract:

Poly(ethyl ethylene phosphonate)-based methacrylic copolymers containing polysiloxane methacrylate (SiMA) co-units are proposed as surface-active additives as alternative solutions to the more investigated polyzwitterionic and polyethylene glycol counterparts for the fabrication of novel PDMS-based coatings for marine antifouling applications. In particular, the same hydrophobic SiMA macromonomer was copolymerized with a methacrylate carrying a poly(ethyl ethylene phosphonate) (PEtEPMA), a phosphorylcholine (MPC), and a poly(ethylene glycol) (PEGMA) side chain to obtain non-water soluble copolymers with similar mole content of the different hydrophilic units. The hydrolysis of poly(ethyl ethylene phosphonate)-based polymers was also studied in conditions similar to those of the marine environment to investigate their potential as erodible films. Copolymers of the three classes were blended into a condensation cure PDMS matrix in two different loadings (10 and 20 wt%) to prepare the top-coat of three-layer films to be subjected to wettability analysis and bioassays with marine model organisms. Water contact angle measurements showed that all of the films underwent surface reconstruction upon prolonged immersion in water, becoming much more hydrophilic. Interestingly, the extent of surface modification appeared to be affected by the type of hydrophilic units, showing a tendency to increase according to the order PEGMA < MPC < PEtEPMA. Biological tests showed that Ficopomatus enigmaticus release was maximized on the most hydrophilic film containing 10 wt% of the PEtEP-based copolymer. Moreover, coatings with a 10 wt% loading of the copolymer performed better than those containing 20 wt% for the removal of both Ficopomatus and Navicula, independent from the copolymer nature.

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Abstract:

A series of well-defined amphiphilic methacrylic AB diblock and ABC triblock copolymers are synthesized via polymerization-induced self-assembly using an alcoholic dispersion polymerization formulation.

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Abstract:

Using synchrotron small angle X-ray scattering (SAXS), self-assembly of ionic supramolecules based upon diblock copolymers of poly(styrene)-b-poly(methacrylic acid) and multi-tail (2- or 4-tail) alkyl quaternary ammonium amphiphiles is investigated.

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Abstract:

Giant polymer vesicles consisting of amphiphilic diblock copolymers are helpful as artificial biomembrane models based on many similarities in their size, structure, morphological transformation, membrane permeability, etc. This paper describes the creation of neuron-like tubule extension employing the polymer vesicles. The polymerization-induced self-assembly was performed in the presence of micron-sized spherical vesicles consisting of poly(methacrylic acid)-block-poly(methyl methacrylate-random-methacrylic acid), PMAA-b-P(MMA-r-MAA), through the photo nitroxide-mediated controlled/living radical polymerization (photo-NMP) using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (MTEMPO) as the mediator. The photo-NMP of methyl methacrylate (MMA) and methacrylic acid (MAA) was carried out in an aqueous methanol solution (CH3OH/H2O = 3/1 v/v) using poly(methacrylic acid) (PMAA) end-capped with MTEMPO and the spherical vesicles of PMAA141-b-P(MMA0.831-r-MAA0.169)368 with an 11.7-mm diameter. The vesicles projected many processes on their surface during the early stage of the polymerization. As the polymerization progressed, only one or two of the processes extended to thick tubules, accompanied by the slow growth of thin tubules. Further progress of the polymerization elongated the thick tubules and caused branching of the tubules. The tubules had a vesicular structure because cup-like vesicles joined in line were formed during the initial stage of the extension. The polymerization livingness supported the tubule extension based on a linear increase in the molecular weight of the component copolymer and a negligible change in the molecular weight distribution versus the monomer conversion. The spherical vesicles were similar to the neurons in the tubule extension for the initial projection, followed by the elongation and branching. This similarity implies that the neurite extension in the neurons is related to the inherent property of the bilayer membrane.

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Abstract:

Nanosized systems of DOX with antitumor activity on the base of micelle-like particles of amphiphilic thermosensitive copolymers of N-vinylpyrrolidone (VP) with triethylene glycol dimethacrylate (TEGDM), and N-vinylpyrrolidone and methacrylic acid (MAA) with TEGDM were explored. They were investigated in aqueous solutions by electron absorption spectroscopy, dynamic light scattering and cyclic voltammetry. Experimental data and quantum-chemical modeling indicated the formation of a hydrogen bond between oxygen-containing groups of monomer units of the copolymers and H-atoms of OH and NH2 groups of DOX; the energies and H-bond lengths in the considered structures were calculated. A simulation of TDDFT spectra of DOX and its complexes with the VP and TEGDM units was carried out. Electrochemical studies in PBS have demonstrated that the oxidation of encapsulated DOX appeared to be easier than that of the free one, and its reduction was somewhat more difficult. The cytotoxicity of VP-TEGDM copolymer compositions containing 1, 5 and 15 wt% DOX was studied in vitro on HeLa cells, and the values of IC50 doses were determined at 24 and 72 h of exposure. The copolymer compositions containing 5 and 15 wt% DOX accumulated actively in cell nuclei and did not cause visual changes in cell morphology.

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Abstract:

The adsorption of methacrylic acid-styrene-acrylic polyethers (MAA-St-APEG) copolymer on the insecticide imidacloprid particles was studied to calculate the kinetic, isotherm and thermodynamic parameters. The kinetic data followed the pseudo-second order kinetic model, and the equilibrium data were well fitted by the Langmuir isotherm model with the maximum adsorption amount of 7.610 mg·g-1 at 298 K. The calculated thermodynamic parameters including ΔG, ΔH and ΔS, demonstrated that this adsorption was a spontaneous and exothermic process in nature. Therefore, MAA-St-APEG copolymer are eligible for the dispersion of imidacloprid particles in aqueous solution as a effective dispersant.