Emulsion Polymerization Of Methyl Methacrylate Research Articles

Emulsion Polymerization of Methyl Methacrylate and Butyl Acrylate Using Non-Ionic Polyurethane as Emulsifier

In this paper, non-ionic polyurethane surfactant which has real good surface activity and better emulsifying capability was totally substitute low molecular weight surfactant for preparing polyacrylate emulsion without any other stabilizer. Kinetics of polymerization was studied and the results showed polymerization with a high rate in initial period and nucleation period was is inversely proportional to the surfactant concentration. The morphology of particles was sphere with core-shell structure. Mechanical testing results shows latex film composed with PUS IGM2000 is better than the one with PUS IGM1000.

Effects of Emulsifier Concentration on Nucleation Mode of Emulsion Polymerization of Methyl Methacrylate

The preparation of polymethyl methacrylate (PMMA) emulsions by semicontinuous dropping method is studied in this paper. The nucleation mode of emulsion polymerization of methyl methacrylate (MMA) under different emulsifier (SDS) concentrations is investigated. Some factors such as conversion, particle number (Np), particle size (PS), polydispersion index (PDI) and coverage rate were examined. The results show that when [SD is close to the CMC (eg. 6mmol/L to 10mmol/L), micelle nucleation will dominates and homogeneous nucleation can coexist, and Np fluctuates. But when [SD is less than 4mmol/L, the homogeneous nucleation dominates and micelle nucleation may also coexist, but Np is constant. It can be concluded that whether the [SD is above or below the CMC, the homogeneous nucleation and micelle nucleation can coexist in the system, but different factors affect the particle number.

Preparation and Properties of Fluorinated Acrylic Latex Modified with Rosin

The fluorinated acrylic latex modified by rosin was prepared successfully via semi-continuous seeded emulsion polymerization of methyl methacrylate (MMA), butyl acrylate (BA), dodecafluoroheptyl methacrylate (DFMA) and rosin in water phase initiated with potassium persulfate (KPS) and emulsified with the aid of mixed surfactants of SDBS and OP-10. The structure of the resultant latex is confirmed by Fourier transform infrared spectroscopy (FTIR) spectrum. The influences of the amount of rosin on the properties of the resultant latex and its film were investigated in detail. Results show that the conversion and gel percentage is decreased with an increase amount of rosin. However, the particle size and glass transition temperature are increased with the increase amount of rosin.

Antimicrobial Particles from Emulsion Polymerization of Methyl Methacrylate in the Presence of Quaternary Ammonium Surfactants

The purpose of this Article is to characterize polymeric particles of poly(methylmethacrylate) (PMMA) synthesized in the presence of one of two different quaternary ammonium surfactants (QACs): cetyltrimethylammonium bromide (CTAB) or dioctadecyldimethylammonium bromide (DODAB). The methods used are dynamic light scattering for sizing, polydispersity and zeta potential analysis, scanning electron microscopy (SEM) for morphology visualization, and plating plus colony-forming unities (CFU) counting for the determination of antimicrobial activity. The results point out the high QAC concentration required to obtain cationic and bioactive antimicrobial particles with good colloidal stability and a permanent load of the polymeric network with QACs. Over a range of micromolar QAC concentrations, there is remarkable antimicrobial activity of PMMA/CTAB or PMMA/DODAB particles, which is much higher than those determined for the QACs by themselves. Loading the biocompatible polyacrylate particles with QACs is a facile, fast, low-cost approach to obtaining highly efficient antimicrobial nanoparticles.

UV cured polymer based on a renewable cardanol derived RAFT agent

A cardanol-derived reversible addition-fragmentation chain transfer (RAFT) agent was synthesized in 57 % total yield, and a cardanol-based anionic surfactant was also facilely prepared. Emulsion polymerization of methyl methacrylate (MMA) was realized to form a cardanol-terminated PMMA polymer by using the novel RAFT agent as well as the cardanol-based anionic surfactant. To improve the properties of cardanol-terminated PMMA as a material, UV-curing was performed. According to the comprehensive behavior of the UV-cured resins, optimal irradiation time was 20 min.

Preparation and characterization of conducting polyaniline layered magnetic nano composite polymer particles

Considering the application potentials of organic materials possessing both conducting and ferromagnetic functions in various electronic devices, an attempt was made to prepare conducting polyaniline (PANI) layered magnetic nano composite polymer particles. Two routes were used to modify magnetic Fe3O4 core particles. In one route, seeded emulsion polymerization of methyl methacrylate (MMA) was carried out in presence of nano‐sized Fe3O4 core particles. In another route, cross‐linker ethyleneglycol dimethacrylate (EGDM) was used in addition to MMA. The modified composite particles were named as Fe3O4/PMMA and Fe3O4/P(MMA‐EGDM), respectively. Finally, seeded chemical oxidative polymerization of aniline was carried out in the presence of Fe3O4/PMMA and Fe3O4/P(MMA‐EGDM) composite seed particles to obtain Fe3O4/PMMA/PANI and Fe3O4/P(MMA‐EGDM)/PANI composite polymer particles. The modification of Fe3O4 core particles was confirmed by electron micrographs, FTIR, UV–visible spectra, X‐ray photoelectron spectra, X‐ray diffraction pattern and thermogravimetric analyses. A comparative study showed that crosslinking of intermediate shell improved the magnetic susceptibility and electrical conductivity of PANI layered magnetic nano composite particles. Copyright © 2013 John Wiley & Sons, Ltd.

Ultrasound assisted synthesis and characterization of poly(methyl methacrylate)/CaCO3 nanocomposites

The combined effects of sonochemical and conventional chemical initiation on the emulsion polymerization of methyl methacrylate (MMA) and MMA–CaCO3 systems have been studied. Combining ultrasound (US) and conventional initiation by potassium persulfate (KPS) for the MMA and MMA–CaCO3 systems, helped increase the final conversion. An increase of 15% for the MMA only system (from 72% to 87%) and of 10% for the MMA–CaCO3 system (from 76% to 86%) was observed as compared to initiation by KPS alone. Also, an increase of 18% (from 69% to 87%) and 20% (from 66% to 86%) for the MMA only and MMA–CaCO3 systems, respectively was observed for the combined initiation as compared to initiation by US alone. Although all particles synthesized were in the size range of 60–130nm, the excellent dispersion ability of ultrasound helped to obtain narrow size distribution and smaller average sizes in both the PMMA and PMMA–CaCO3 systems. Possible mechanisms have been proposed for both the polymerization and the formation of poly-MMA–CaCO3 composite and core–shell nanoparticles taking into account the results obtained by analyzing the synthesized materials.

RAFT-mediated one-pot aqueous emulsion polymerization of methyl methacrylate in presence of poly(methacrylic acid-co-poly(ethylene oxide) methacrylate) trithiocarbonate macromolecular chain transfer agent

The polymerization-induced self-assembly of amphiphilic block copolymers in water was performed following a reversible addition-fragmentation chain transfer (RAFT) controlled radical polymerization mechanism in emulsion. Poly(methacrylic acid-co-poly(ethylene oxide) methyl ether methacrylate), P(MAA-co-PEOMA), with a trithiocarbonate reactive end-group was selected as the water-soluble living precursor and synthesized in situ via a RAFT aqueous solution polymerization process. The study focused on the polymerization of methyl methacrylate (MMA) at pH 3.5, 5 and 7 and its copolymerization with various proportions of styrene (S) at pH 3.5. In the homopolymerization of MMA, the reaction was well-controlled at pH 3.5, while a low blocking efficiency was observed at higher pH. The systems led to spherical micelles, fibers and then vesicles when the molar mass of the hydrophobic block was increased, irrespective of the pH of the aqueous phase. In the case of the copolymerization with styrene at pH 3.5 and in chain length conditions leading to fibers for the homopolymerization of MMA, the control was very good but the final morphology was that of spherical particles only, at all compositions studied, exactly like in the homopolymerization of styrene performed under similar experimental conditions [Zhang et al. Macromolecules 2011; 44:7584–93]. The results were interpreted on the basis of an influence of the polymerization kinetics, especially in the early stage of the reaction in the aqueous phase.

Preparation of poly(methyl methacrylate) nano-latexes via UV irradiation in the presence of iron aqueous solution

AbstractThe UV-initiated emulsion polymerization of methyl methacrylate (MMA) in the presence of FeCl3 was studied. The photopolymerization presented high efficiency even though using a small percentage of photoinitiator. The entire polymerization could be performed within 10 min and displayed a conversion higher than 90% at ambient temperature. The particle sizes could be tuned in the range of 20-90 nm. The effects of content of initiator and emulsifying agent upon the reaction conversion, distribution of molecular weight, diameter of particles and glass-transition temperature were examined. 1H-NMR technique was used to investigate the structural properties of PMMA.

Synthesis of High Solid Content Acrylic-Polyurethane Hybrid Emulsions with Low Viscosity

The emulsion polymerization of methyl methacrylate (MMA) with butyl acrylate (BA) using aqueous polyurethane dispersion as seed was undertaken to prepare acrylic-polyurethane (PUA) hybrid emulsions with high solid content. The concentrations of the anionic groups were varied by adding different amount of dimethylolpropionic acid (DMPA). The emulsions with a similar bimodal particle size distribution (PSD) were obtained. The viscosity of the emulsions is about 350 mPa.s while the solid content is about 55%.

Core‐shell latex synthesized by emulsion polymerization using an alkali‐soluble resin as sole surfactant

AbstractA series of alkali‐soluble resins were prepared from esterification reaction of styrene‐maleic anhydride copolymer (SMA) and four fatty alcohols having different alkyl chains. The critical aggregates concentration of the prepared hemiester was lower than SMA, indicating that modification of SMA resin with long alkyl chains could improve their emulsification efficiency. The detailed experiments of emulsion polymerization of methyl methacrylate and butyl acrylate using these hemiesters as sole surfactants showed that SMA‐C12‐75, SMA‐C14‐70, and SMA‐C16‐65 were good surfactants. In the end, we successfully prepared stable latexes using above three good surfactants with relatively low surfactant concentration and high solid content. Characterization of latexes by Zetasizer and transmission electron microscopy revealed that particles of these latexes have core‐shell nanostructure with average particle size below 60 nm. Compared with SMA, the improvement of emulsification efficiency of its hemiesters may come from the better hydrophilic‐lipophilic balance and steric stabilization after incorporation of long alkyl chain. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Efficient Synthesis of Snowman- and Dumbbell-like Silica/Polymer Anisotropic Heterodimers through Emulsion Polymerization Using a Surface-Anchored Cationic Initiator

We report a novel original synthetic route to hybrid dissymmetrical snowman- and dumbbell-like silica/polymer colloidal particles through emulsion polymerization of methyl methacrylate (MMA) or styrene using a bicationic initiator previously anchored on the silica surface. Anisotropic particles with a polymer nodule attached to a single silica sphere were successfully obtained in high yield in the presence of a mixture of nonionic and anionic surfactants under optimized initiator concentration conditions. Both nonionic surfactant and cationic initiator were key ingredients in controlling particle morphology as evidenced by transmission electron microscopy. By optimizing the silica content and the surfactant composition, latexes with a latex-to-silica seed number ratio (NLatex/NSilica) close to 1 were produced using either MMA or styrene as monomers. Their shapes evolved from snowman-like and reverse snowman-like at low and high conversions to dumbbell-like for intermediate conversions. The evolution of particle morphology with time provided insights into the mechanism of composite particles formation.

One-Pot Preparation of Core-Shell, Organic-Inorganic, Hybrid Latexes by In Situ Nanoparticle Precipitation in Pickering Emulsion Polymerization

A one-pot emulsion polymerization process to produce silica nanoparticles fi xed on polymer particles is presented. Simultaneous nanoparticle formation/monomer emulsifi cation and later polymerization of monomers prevent the agglomeration of silica particles and result in hybrid organic–inorganic, core–shell latexes. The emulsion polymerization of methyl methacrylate is performed using nascent silica nanoparticles, cetyltrimethylammonium bromide, and ammonium persulfate as Pickering surfactant, cosurfactant, and initiator, respectively. The effects of parameters like temperature, initiator type and concentration, and cosurfactant and silica precursor amounts on the polymerization, coagulation percentage, and morphology of hybrid particles are determined using SEM and TEM.

PTFE–PMMA core–shell colloidal particles as building blocks for self‐assembled opals: synthesis, properties and optical response

AbstractA seeded surfactant‐free methyl methacrylate emulsion polymerization is employed to prepare core–shell particles with predetermined size and narrow size distribution. The particle size is determined by the ratio between methyl methacrylate (MMA, shell) and polytetrafluoroethylene (PTFE, core). Monodisperse particles in the 100–350 nm range are obtained. These particles are used to grow colloidal photonic crystals (opals) of very high optical quality, thus indirectly demonstrating the excellent control of microbead size distribution achieved by this preparation technique. The optical properties of the opals are investigated by means of reflectance and polarized‐angle‐resolved transmittance spectroscopies. These data provide a rough determination of the effective refractive index of the system, which is favorably compared with values obtained by simple effective medium models. Copyright © 2012 Society of Chemical Industry

Aryl Amidine and Tertiary Amine Switchable Surfactants and Their Application in the Emulsion Polymerization of Methyl Methacrylate

The switchability and bicarbonate formation of CO2 triggered aryl amidine and tertiary amine switchable surfactants have been investigated. Despite the lower basicity of these compounds compared to alkylacetamidine switchable surfactants, it was found that amidinium and ammonium bicarbonates could be formed in sufficiently high enough concentrations to perform emulsion polymerization of methyl methacrylate and stabilize the resulting colloidal latexes. Particle sizes ranging from 80 to 470 nm were obtained, and the effects of surfactant concentration, surfactant basicity, initiator type, initiator concentration, and CO2 pressure on particle size and ζ-potential have been examined. Destabilization of latexes is traditionally achieved by addition of salts, strong acids for anionically stabilized latexes, or alkalis for cationically stabilized latexes. However, with CO2-triggered switchable surfactants, only air and heat are required to destabilize the latex by removing CO2 from the system and switching the ...

In‐situ real‐time monitoring of particle size, polymer, and monomer contents in emulsion polymerization of methyl methacrylate by near infrared spectroscopy

AbstractThis work reports the results of in‐situ real‐time monitoring of the emulsion polymerization of methyl methacrylate by near infrared spectroscopy (NIRS) under different feed conditions. Besides the monitoring of the monomer and polymer content, the results show that reasonable estimates can be obtained from the spectra for the average particle size of the growing polymer particles present in the reaction medium. This is possible because the presence of the particles affects the spectra (through scattering, diffraction, and other mechanisms). Thus, by using appropriate calibration, it is possible obtain reliable models for particle size, in addition to monitoring the monomer and polymer concentrations. Experimental results for emulsion polymerizations conducted with various feed monomer conditions indicated that, in the spectral range studied, it is not only possible to monitor the evolution of the monomer and polymer contents, but also to follow the changes in the average size of the polymer particle. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

The Preparation of Core-Shell Type Acrylic-Polyurethane Composite Emulsions for Pigment Printing

Vinyl-endblocked polyurethanes were prepared from polyether diols(N210), isophorone diisocyanate (IPDI), dimethylol propionic acid (DMPA) and 2-hydroxyethyl acrylate (HEA). The core-shell structure acrylic-polyurethane composite emulsion was prepared by seeded emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (BA) using the polyurethanes emulsions as seeded emulsions. The core and shell regions were occupied by acrylic polymer and polyurethane, respectively. Because polyurethanes were vinyl-endblocked, acrylic monomers could graft partially to them. The formation of core-shell structure was observed by transmission electron microscopy (TEM). The structure and properties of dried film were studied by Fourier-transform infrared spectroscopy (FT-IR) and TGA.

Synthesis and electrical conductivity evaluation of novel hybrid poly (methyl methacrylate)/titanium dioxide nanowires

This work aims at preparation, characterization and electrical conductivity evaluation of novel poly (methyl methacrylate), PMMA, based nanocomposites. The sodium titanate nanowire (Na2TinO2n+1) was prepared using titanium dioxide nanoparticles via hydrothermal treatment method. The hybrid PMMA nanocomposites were prepared by in situ emulsion polymerization of methyl methacrylate in presence of cetyl trimethyl ammonium bromide and potassium persulfate as a cationic surfactant and initiator, respectively. In addition to, PMMA/polyaniline (PA)-based nanocomposites were obtained by adding sodium titanate nanowires and/or silver nitrate nanoparticles into the polymer mixture. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction pattern (XRD) and infrared spectroscopy (FT-IR) were used to characterize the structures of the nanocomposites. The resultant nanocomposites exhibited core–shell structure. Moreover, the conductivity of the prepared hybrid PMMA nanocomposites was increased from 1.32×10−8 to 5.9×10−5scm−1 with an increasing of the titanium dioxide nanowires concentration.

Block Copolymer Surfactants in Emulsion Polymerization: Influence of the Miscibility of the Hydrophobic Block on Kinetics, Particle Morphology, and Film Formation

A brush type amphiphilic block copolymer of polystyrene-b-poly[poly(ethylene glycol) methyl ether methacrylate], PS40-b-PPEGMA70, obtained via ATRP was used as stabilizer in the emulsion polymerization of methyl methacrylate. It was shown that the incompatibility between the growing polymer particles of poly(methyl methacrylate) and the hydrophobic segment of the block copolymer surfactant (polystyrene) affects both the kinetics of the emulsion polymerization and the resulting particle morphologies. Because of the incompatibility of the two polymers, phase separation occurs, and the particle morphology changes from roughly spherical core–shell to more irregular with particles containing clusters of block copolymer surfactant as the amount of block copolymer surfactant increases. This in turn has an effect on the film formation, which results in turbid films. The results obtained from the emulsion polymerization of methyl methacrylate, the obtained hairy latex particles, and the film formation process were...

Emulsifier-free emulsion polymerization of methyl methacrylate containing hydrophilic magnetite nanoparticles

Emulsifier-free emulsion polymerization of methyl methacrylate was carried out in the presence of hydrophilic magnetite nanoparticles using a persulfate initiator. Before the magnetic nanoparticles were placed into the polymerization system, they were dispersed and stabilized electrostatically with perchloric acid in water (magnetic sol). For magnetic nanoparticles in the sol, the hydrodynamic radius and polydispersity index (PDI) measured by dynamic light scattering was 18.8 nm and PDI of 0.282, respectively. The latex sizes also were determined to be 125–223 nm with a PDI of 0.009–0.065. Magnetic measurements by vibrating sample magnetometry confirmed that the magnetite nanoparticles and magnetic poly(methyl methacrylate) nanospheres exhibited superparamagnetism with zero coercivity. The saturation magnetization of the magnetic polymeric nanospheres ranged from 0.2 to 1.19 emu/g depending on the magnetite content. The polymer chain terminations were affected by the addition of magnetite nanoparticles to the polymerization system. In addition, the magnetite that reduced the average molecular weight of the polymers obtained by gel permeation chromatography should be defined as a transfer agent.