Methyl Methacrylate Butyl Acrylate Research Articles

SOAP-FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE-BUTYL ACRYLATE WITH SODIUM α-OLEFIN SULFONATES AS FUNCTIONAL MONOMER

Sodium salt of α-olefin sulfonates(AOS),a mixture of sulfonated unsaturated linear hydrocarbon with carbon numbers from C12 to C14,is used in methyl methacrylate/butyl acrylate(MMA/BA)soap-free emulsion copolymerization.The reactivity ratios of AOS-MMA are determined to be r_A=1.98 and r_M=0.034 for AOS and MMA respectively.In order to assure distribution of AOS units on the out-shell layer of the particles,a semi-continuous emulsion polymerization is used.Latex of high solids of up to 60% has been obtained with 5% AOS.And with 1% AOS,latex solids can reach to 45% with good stability,whereas this value is limited to 40% with sodium dodecyl sulfate(SDS) as surfactant.The particle size is in constant increase with latex solids combined with a sharp decrease in particle number when AOS is used;while the particle size and number of particles are kept relatively constant when SDS is used as surfactant.This is attributed to the fact that SDS can either adsorb on or desorb from the particle surface,and AOS would be fixed on a position on the particle surface once copolymerized with MMA and BA.The AOS prepared latex also shows a narrower particle size distribution,and the latex with 35% is stable after a shelf standing of up to one year.

Synthesis of copolymer-stabilized silver nanoparticles for coating materials

Silver ions being less toxic than silver nanoparticles, a more safe material can be obtained to be used as antimicrobial coating. This can be achieved by using thiol chemistry and covalently attach the silver nanoparticles in the coating. Our aim is to produce a coating having antimicrobial properties of silver ions but with the silver nanoparticles firmly attached in the coating. Here, we present a way to produce silver nanoparticles that can be used as a component in a coating or as such to produce an antimicrobial coating. The silver nanoparticles presented here are stabilized by a copolymer (poly(butyl acrylate–methyl methacrylate)) that is soft and has well-known good film-producing properties. The reversible addition-fragmentation chain transfer radical polymerization technique used to prepare the polymers provides conveniently a thiol group for effective binding of the silver nanoparticles to the polymers and thus to the coating.

Partial volume and compressibility at infinite dilution of functionalized multilayer latex particles

A series of functionalized multilayer latex particles of P(butyl acrylate–methyl methacrylate–acrylic acid) was synthesized. The total acrylic acid concentration inside particles was varied from 0 to 25 wt.% and the number of particles in the system was held constant. The polymeric particles were studied by means of specific partial volume and specific partial compressibility at infinite dilution, which were calculated from density and sound speed measurements. From the behaviour of the partial properties at infinite dilution of the polar and non-polar groups of the polymer chain, it was concluded that the particle swells at low acrylic acids content due to the electrostatic repulsion between the carboxylic groups of the polymer chain. From 15 wt.% of acrylic acid up, the particle swells due to the electrostatic repulsion and to the incorporation of water molecules in the bounds of the particle layers. In this way, the hydration is non-homogeneous in the interior of each layer. These results are in agreement with the behaviour of the hydrodynamic radius determined by the quasi-elastic light scattering technique.

The onset of polymer diffusion in a drying acrylate latex: how water initially retards coalescence but ultimately enhances diffusion

The diffusion of polymer chains across the interface between distinct latex particles is the final step in latex film maturation. This step drives the transformation of a honeycomb of compacted latex particles bound by weak surface forces into a mechanically robust film. Knowledge of the onset of this diffusion process is limited. We have examined film formation in butyl acrylate-methyl methacrylate copolymer latex containing 1 wt% methacrylic acid. These films dry via a propagating drying front. We were able, via fluorescence resonance energy transfer measurements, to determine the extent of polymer interdiffusion at 23°C as a function of distance from the edge of the drying front for a series of partly wet latex films. Our apparatus allows us to arrest the latex drying process and to extract interdiffusion information from sub-millimeter regions of the drying film. We have tracked the latex drying process and subsequent polymer diffusion as a function of humidity. We find that adjacent to the drying front, increasing humidity initially delays the onset of interdiffusion, but once this initial barrier is overcome increasing humidity increases the rate of diffusion. This transition occurs within 1–2 mm of the drying front.

Synthesis of tercopolymer BA–MMA–VTES and surface modification of nano‐size Si3N4 with this macromolecular coupling agent

AbstractA new macromolecular coupling agent butyl acrylate (BA)‐methyl methacrylate (MMA)‐vinyl triethoxy silane (VTES) tercopolymer was synthesized using solution polymerization initiated by free radical initiator benzoyl peroxide (BPO) and dicumyl peroxide (DCP). Dodecylthiol is choosed as the chain transfer to control the molecule weight of this tercopolymer. The terpolymer's molecular structure was confirmed by FTIR and NMR, and its average molecular weight was determined by GPC. In this work, the tercopolymer BA–MMA–VTES is used for surface modification of silicon nitride (Si3N4) nanopowder. The structure surface properties and thermal stability of modified nano‐Si3N4 were systematically investigated by FTIR, TGA, TEM, and size distribution analyzer. The results show that the macromolecular coupling agent bonds covalently on the surface of nano‐sized Si3N4 particles and an organic coating layer is formed. The optimum loading of this macromolecular coupling agent BA–MMA–VTES tercopolymer is 5% (wt %) of nano‐sized Si3N4. TEM also reveals that modified nano‐Si3N4 possesses good dispersibility. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Solubility and diffusivity of methylmethacrylate and butylacrylate monomers in a MMA–BA copolymer

AbstractMutual diffusion coefficients and sorption isotherms of methyl methacrylate (MMA) and butyl acrylate (BA) monomers in methyl methacrylate‐butyl acrylate copolymer (MMA‐BA) have been measured by gravimetric sorption. MMA is found to have higher solubility and diffusion rates in the copolymer than BA. Sorption data for MMA were interpreted using classical Flory‐Huggins thermodynamic theory with a constant interaction parameter (χ). A modified version of this theory has been applied to correlate the sorption data of BA, which exhibit a temperature and concentration‐dependent χ parameter. For MMA, the isotherm data reveal enhanced polymer‐solvent interactions with increasing temperature, while for BA the data indicate a drive toward phase separation with increasing temperature. Despite the difference in thermodynamic behavior, both monomers are found to exhibit Fickian diffusion and the diffusivity data are correlated reasonably well with the Vrentas‐Duda free volume theory. Some deviation between the free‐volume correlation and the experimental data is observed at the lowest temperature and BA concentration examined. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1996–2006, 2007

Synthesis and characterization of poly(butyl acrylate–methyl methacrylate)/polyaniline core–shell latexes

AbstractPoly(butyl acrylate–methyl methacrylate) [P(BA–MMA]/polyaniline (PANI) core–shell complex particles were synthesized with a two‐step emulsion polymerization method with P(BA–MMA) as the core and PANI as the shell. The first step was to prepare P(BA–MMA) latex particles as the core via soapless emulsion polymerization. The second step was to prepare P(BA–MMA)/PANI core–shell particles. Sodium dodecyl sulfate was fed into the P(BA–MMA) emulsion as a surfactant, and this was followed by the addition of the aniline monomer. A bilayer structure of the surfactant over the surfaces of the core particles was desired so that the aniline monomer could be attracted near the outer surface of the core particles. In some cases, dodecyl benzene sulfonic acid was added after 2 h when the polymerization of aniline was started. The final product was the desired core–shell particles. The morphology of P(BA–MMA) and P(BA–MMA)/PANI particles was observed with transmission electron microscopy. The thermal properties were studied with thermogravimetric analysis and differential scanning calorimetry. Furthermore, conductive films made from the core–shell latexes were prepared, and the electrical conductivities of the films were studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 823–830, 2007

STUDIES ON THIN LAYER COPOLYMERIZATION OF THE CONCENTRATED EMULSION OF MMA-BA INITIATED BY THE REDOX SYSTEM AT LOW TEMPERATURE

The stable concentrated emulsions of methyl methacrylate-butyl acrylate(MMA-BA) are prepared using sodium dodecyl sulfate(SDS) and cetyl alcohol(CA) as the compound surfactants,polyvinyl alcohol(PVA) as the reinforcer of liquid films.A novel method of polymerization,the thin layer copolymerization of the concentrated emulsion,was carried out with benzoyl peroxide/N,N′-dimethyl aniline(BPO/DMA) as redox initiators at low temperature.Effects of categories of the reinforcer of liquid films and the polymerization environment on polymerization stability were introduced.The effect of the thickness and area of films,the outside temperature,and environment of polymerization on the amount of volatilization were investigated.The conversion comparison of the thin layer polymerization with the tube polymerization and the effect of polymerization environment on the polymerization rate were discussed also.The size and distribution of particle diameter and morphology of latex particles were determined with TEM.

Proton exchange membranes based on PVDF/SEBS blends

Proton-conductive polymer membranes are used as an electrolyte in the so-called proton exchange membrane fuel cells. Current commercially available membranes are perfluorosulfonic acid polymers, a class of high-cost ionomers. This paper examines the potential of polymer blends, namely those of styrene–(ethylene-butylene)–styrene block copolymer (SEBS) and polyvinylidene fluoride (PVDF), in the proton exchange membrane application. SEBS/PVDF blends were prepared by twin-screw extrusion and the membranes were formed by calendering. SEBS is a phase-segregated material where the polystyrene blocks can be selectively functionalized offering high ionic conductivity, while PVDF insures good dimensional stability and chemical resistance to the films. Proton conductivity of the films was obtained by solid-state grafting of sulfonic acid moieties. The obtained membranes were characterized in terms of conductivity, ionic exchange capacity and water uptake. In addition, the membranes were characterized in terms of morphology, microstructure and thermo-mechanical properties to establish the blends morphology–property relationships. Modification of interfacial properties between SEBS and PVDF was found to be a key to optimize the blends performance. Addition of a methyl methacrylate–butyl acrylate–methyl methacrylate block copolymer (MMA–BA–MMA) was found to compatibilize the blend by reducing the segregation scale and improving the blend homogeneity. Mechanical resistance of the membranes was also improved through the addition of this compatibilizer. As little as 2 wt.% compatibilizer was sufficient for complete interfacial coverage and lead to improved mechanical properties. Compatibilized blend membranes also showed higher conductivities, 1.9 × 10 −2 to 5.5 × 10 −3 S cm −1, and improved water management.

MMA계 아크릴 라텍스를 혼입한 폴리머시멘트 모르타르의 내구성

Polymer-modified mortar and concrete are prepared by mixing either a polymer or monomer in a dispersed, or liquid form with fresh cement mortar and concrete mixtures, and subsequently curing, and if necessary, the monomer contained in the mortar or concrete is polymerized in situ. Although polymers and monomers in any form such as latexes, water-soluble polymers, liquid resins, and monomers are used in cement composites such as mortar and concrete, it is very important that both cement hydration and polymer phase formation proceed well the yield a monolithic matrix phase with a network structure in which the hydrated cement phase and polymer phase interpenetrate. In the polymer-modified mortar and concrete structures, aggregates are bound by such a co-matrix phase, resulting in the superior properties of polymer-modified mortar and concrete compared to conventional mortar and concrete. The purpose of this study is to obtain the necessary basic data to develope appropriate latexes as cement modifiers, and to clarify the effects of the monomer ratios and amount of emulsifier on the properties of the polymer-modified mortars using methyl methacrylate-butyl acrylate(MMA/BA) and methyl methacrylate-ethyl acrylate(MMA/EA) latexes. The results of this study are as follows, the water absorption, chloride ion penetration depth and carbonation depth of MMA/BA-modified mortar are lowest. However, they are greatly affected by the polymer-cement ratio rather than the bound MMA content and type of polymer.

One‐component epoxy resin with imine as water‐initiated latent hardener: Improvement of the mechanical and adhesive properties by the addition of methacrylate copolymer

AbstractThe effect of addition of methacrylate polymer into a one‐component epoxy resin, containing Epikote 828 and diimine as a water‐initiated hardener, was examined. Although the cured epoxy resin in the presence of methyl methacrylate–butyl acrylate (MMA–BA) copolymer was very brittle, the resin containing MMA–BA–[γ‐(methacryloxy)propyl]trimethoxysilane (TMSMA) copolymer showed good mechanical and adhesive properties. The adhesive strength of the cured epoxy resin containing MMA–BA–TMSMA copolymer was much higher than that without its polymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1943–1949, 2005

Reversible addition fragmentation chain transfer copolymerization: influence of the RAFT process on the copolymer composition

Reversible addition fragmentation chain transfer (RAFT) mediated and conventional copolymerizations at low monomer conversions have been carried out for the systems methyl methacrylate (MMA)-styrene, methyl acrylate (MA)-styrene and methyl methacrylate-butyl acrylate (BA). The polymer samples have been analyzed via 1H-NMR spectroscopy to obtain the copolymer composition and the terminal model reactivity ratios. In the RAFT mediated copolymerizations, the polymer mole fraction of the monomer with the larger reactivity ratio is increased compared to the conventional copolymerization. Simulations have been carried out using the program package PREDICI ® to examine possible explanations for the experimental findings. The simulations demonstrate that the RAFT process itself may alter the macroradical populations and the copolymer composition by offering additional reaction pathways. Further, the rate coefficients for the initiation reaction and the pre-equilibrium play an important role in determining the copolymer composition. The rate coefficients governing the main equilibrium of the RAFT process have only a minor impact on the copolymer composition.

Butyl acrylate/methyl methacrylate latexes: adhesive properties

AbstractIn this study, butyl acrylate/methyl methacrylate (BA/MMA) latexes of bimodal molecular weight and particle size distribution were prepared in a multi‐step process by seeded conventional emulsion and seeded miniemulsion polymerization. For the conventional emulsion case, a BA/MMA batch copolymerization was conducted as a first step (seed generation) and was followed by a monomer addition step to ensure particle growth. In a third step, a BA/MMA pre‐emulsified mixture was added to generate a second particle population. For the miniemulsion case, a BA/MMA copolymerization was carried out as a first step (seed generation) and was followed by a monomer addition step. The addition of a BA/MMA miniemulsion served to generate a bimodal particle size and molecular weight distribution. The final latexes were coated onto a polyethylene terephthalate carrier, dried and their performance as pressure‐sensitive adhesives was evaluated using tack, peel and shear adhesion measurements. Structure‐property relationships between the adhesive properties and the weight‐average molecular weight and average particle size were examined. Even though the polymers obtained by miniemulsion showed better shear resistance, their shear resistance was low. There was no statistically significant difference in peel resistance of the polymers obtained by the two reactions. While a significant difference in tackiness between the two emulsion procedures was found when the adhesives were tested using the less sensitive, rolling ball test, no differences were found when they were tested using a loop tack test.

Effect of the monomer ratio on the properties of poly(methyl methacrylate butyl acrylate) latex-modified mortars

This article deals with the effect of the monomer ratio on the typical properties of polymer-modified mortars with poly(methyl methacrylate butyl acrylate) latices. Polymer-modified mortars, with methyl methacrylate/butyl acrylate copolymer latices of various methyl methacrylate/butyl acrylate ratios, were prepared with different polymer/cement ratios and were tested for their workability, air content, compressive strength, flexural strength, and water absorption. On the basis of the test results, the effects of the monomer ratio and polymer/cement ratio on the typical properties were examined. The properties of the latex-modified mortars were affected to a great extent by both the monomer ratio and polymer/cement ratio. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2403–2409, 2004

Controlled coagulation of emulsion polymers

Coagulation of latex particles is most often carried out in the diffusion limited aggregation (DLA) regime where the time for coagulation to take place is on the millisecond timescale. This process produces aggregates of low density, irregular shape, and a broad particle size distributions. When the coagulation is carried out in the reaction limited aggregation (RLA) regime, a coagulation time of about 1–120 sec, the system can be controlled by mixing to yield dense, spheroidal aggregates with a very narrow particle size distribution. The important variables in the RLA process for butyl acrylate/methyl methacrylate (BA/MMA) latexes were found to be mixing intensity, latex copolymer composition, and coagulation temperature. Dried aggregates formed in the RLA process were found to have excellent powder flow properties and low dustiness.

Mathematical Modeling of Batch Emulsion Copolymerization Processes

A general mathematical model for emulsion copolymerization processes in batch reactor is presented. The model predicts the time‐history of monomer conversion, average particle size, copolymer composition and number of particles. The model was tested and validated with experimental data of four different copolymerization systems: S/MMA (styrene/methyl methacrylate), S/BA (styrene/butyl acrylate), MMA/BA (methyl methacrylate/butyl acrylate) and MMA/VA (methyl methacrylate/vinyl acetate). The influence of several process variables, such as initiator concentration, emulsifier concentration, monomer‐to‐water ratio, and composition has been examined. Model predictions presented satisfactory agreement with the experimental data. Despite the model simplicity and the reduced number of adjustable parameters, the model accounts for the basic features of emulsion polymerization processes and can be useful for practical applications.

모노머비를 변화한 MMA/BA 합성 라텍스 혼입 폴리머 시멘트 모르타르의 성질

The purpose of this study is to clarify the effect of the monomer ratio on properties of the polymer-modified mortars using methylmethacrylate-butyl acrylate(MMA/BA) latexes, and to obtain basic data necessary to develop appropriate latexes for cement modifiers. From the test results, we knew that the pore volume of polymer-modified mortars using MMA/BA latexes at bound MMA contents of 60 and 70 percent is 7.5∼75nm and the fine pore volume is increased with an increase in the polymer-cement ratio. The total pore volume of polymer-modified mortars using MMA/BA latexes is linearly reduced with an increase in the bound MMA content and increased in the polymer-cement ratio. In general, the superior compressive strength of polymer-modified mortars using MMA/BA latexes is obtained at a bound MMA content of 70 percent and a polymer-cement ratio of 15%. And, the water absorption and chloride ion penetration depth are greatly affected by the polymer-cement ratio rather than the bound MMA content. The important factors affecting the properties of polymer-modified mortars using MMA/BA latexes polymerized with various monomer ratios are the variations of the pore size distribution with changing bound MMA content and the polymer-cement ratio.

Study on swelling behavior and pervaporation properties of AA–MMA–BA copolymers for separation of methanol/MTBE/C5 mixtures

AbstractIn this study, the copolymers with different ratios of AA(acrylic acid)–MMA(methyl methacrylate)–BA (butyl acrylate) are synthesized to prepare pervaporation membrane for the separation of methanol/MTBE (methyl tert‐butyl ether)/C5 mixtures. Swelling experiment of these copolymers in pure methanol, MTBE, C5, and methanol/MTBE mixtures are carried out, respectively. The results show that there is a strong interaction between MTBE and copolymer with high content of BA. The pervaporation characteristics of the membranes prepared with different copolymer are measured in the separation of methanol/MTBE mixture. The experimental results show that the pervaporation ability changes with swelling degree in the same direction. The copolymers are characterized by FTIR. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2267–2271, 2003

Glass transition temperatures of butyl acrylate-methyl methacrylate copolymers

Glass transition temperatures of butyl acrylate-methyl methacrylate copolymers

Glass transition temperatures of butyl acrylate-methyl methacrylate copolymers

The glass transition temperatures Tg of butyl acrylate–methyl methacrylate copolymers obtained by free radical polymerization in 3 and 5 mol/L benzene solution have been measured using differential scanning calorimetry (DSC) and the values have been correlated using Johnston's equation with inter-intramolecular copolymer structure. From the data calculated with copolymer prepared at low conversion, the variation of glass transition temperature with copolymer conversion has been theoretically predicted. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2512–2520, 1999