Emulsion Copolymerization Of Methyl Methacrylate Research Articles

Printable Single‐Ion Polymer Nanoparticle Electrolytes for Lithium Batteries

New material solutions are searched for the manufacturing and safety of current batteries. Herein, an extrusion printable polymer separator for lithium batteries based on single‐ion polymer electrolytes is presented. The polymer electrolytes are based on methacrylic polymeric nanoparticles (NPs) functionalized with a lithium sulfonamide group combined with different organic plasticizers such as sulfolane and carbonates. The synthesis of the polymer NPs is carried out by emulsion copolymerization of methyl methacrylate and lithium sulfonamide methacrylate in the presence of a crosslinker, resulting in particle sizes of less than 30 nm, as shown by electron microscopy. Then polymer electrolytes are prepared by mixing polymer NPs with varying lithium sulfonamide content and different plasticizers such as carbonates and sulfolane. The polymer electrolytes show ionic conductivities between 2.9 × 10−4 and 2.3 × 10−5 S cm−1 at 85 °C with the highest values for the small‐sized NPs with the highest lithium content. As a proof‐of‐concept application, layer‐by‐layer printing of a sulfolane‐based polymer electrolyte is evaluated via direct ink writing directly onto classic battery electrodes. The electrochemical characterization of the printed solid electrolyte indicates favorable properties, ionic conductivity, lithium transfer number, electrochemical stability window, and cyclability in lithium symmetrical cells, to be used in lithium batteries.

Chameleon-like Photoluminescent Janus Nanoparticles as Full-Color Multicomponent Organic Nanoinks: Combination of Förster Resonance Energy Transfer and Photochromism for Encryption and Anticounterfeiting with Multilevel Authentication.

Increasing the security by the multilevel authentication mechanism was the most significant challenge in recent years for the development of anticounterfeiting inks based on photoluminescent nanomaterials. For this purpose, the greatest strategy is the use of multicomponent organic materials and a combination of Förster resonance energy transfer (FRET) with the intelligent behavior of photochromic compounds like spiropyran. Here, the hydroxyl-functionalized polymer nanoparticles were synthesized by emulsion copolymerization of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) in different compositions (0-30 wt % of HEMA). Results illustrated that the size of the nanoparticles changed from 64 to 204 nm, and a morphology evolution from spherical to Janus shape was observed by increasing the concentration of HEMA. Photoluminescent inks with red, green, and blue (RGB) fluorescence emissions were prepared by modification of nanoparticles containing 15 wt % of HEMA with spiropyran, fluorescein, and coumarin, respectively. To develop dual-color and multicolor photoluminescent inks that display static and dynamic emission, RGB latex samples were mixed together in different ratios and printed on cellulosic paper. Results display that the fluorescence emission of developed inks can be photoswitched between different statuses, including white to blue, green to blue, green to red/orange, purple to pink, and white to pink, utilizing the FRET phenomenon, photochromism, and a combination of both phenomena. Samples containing spiropyran displayed dynamic color changes in the emission to red, orange, and pink depending on the composition. Hence, developed dual-color and multicolor photoluminescent inks were used for printing of security tags and also painting of some hand-drawn artworks, which obtained results indicating high printability, maximum fluorescence intensity, high resolution, and fast responsivity upon UV-light irradiations of 254 nm (for static mode) and 365 nm (for dynamic mode). In addition, the multilevel authentication mechanism by a static emission under UV-light irradiation of 254 nm, a dynamic emission under UV-light irradiation of 365 nm, and photochromic color change was observed, resulting in increasing the security of developed inks. Actually, developed multicolor photoluminescent inks are the most efficient candidates for developing a new category of chameleon-like high-security anticounterfeiting inks that have tunable optical properties and complex multilevel authentication mechanisms.

Degradable vinyl polymer particles by radical aqueous emulsion copolymerization of methyl methacrylate and 5,6-benzo-2-methylene-1,3-dioxepane

Aqueous emulsion copolymerization of methyl methacrylate (MMA) and 5,6-benzo-2-methylene-1,3-dioxepane (BMDO) leads to stable particles of PMMA bearing in-chain ester units that can be cleaved under basic conditions.

Photoluminescent Nanoinks with Multilevel Security for Quick Authentication of Encoded Optical Tags by Sunlight: Effective Physicochemical Parameters on Responsivity, Printability, and Brightness.

Investigation of developed photoactive security inks and anticounterfeiting technologies in recent years indicates significant challenges for future of this research area, such as increase of security, fast responsivity, and facile authentication. Here, amine-functionalized latex nanoparticles were synthesized by emulsion copolymerization of methyl methacrylate (MMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). Size of the latex nanoparticles was increased as a function of poly(dimethylaminoethyl acrylate) (PDMAEMA) contents, and also a decrease of particle size was obtained in response to an increase of temperature from 25 to 70 °C, above the lower critical solution temperature (LCST) of PDMAEMA. Surface physical modification of the functional latex nanoparticle with spiropyran photoswitches led to the development of anticounterfeiting nanoinks that have multilevel security and photochromic/fluorescence properties with a higher intensity and also brightness. The photoluminescent nanoinks were made of spiropyran latex nanoparticles and used for printing of the encoded optical security tags on cellulosic papers and banknotes. The results displayed that an increase of the particle size above 100 nm and an increase of the PDMAEMA contents led to a remarkable decrease of printability, fluorescent emission, brightness, intensity of photochromism, and also resolution of the printed security tags. As a significant advantage of the developed security inks, the printed security tags could be authenticated easily and fast upon sunlight irradiation by means of photochromism. The responsivity of encoded tags from the invisible to visible state is immediate upon sunlight irradiation for some seconds, whose intensity of coloration is appropriate and detectable clearly by naked eyes. The security anticounterfeiting inks based on spiropyran with multilevel security have been reported for the first time for applying in printing of encoded security tags on cellulosic papers, banknotes, and other documents, where the printed marks are detectable on sunlight exposure.

Polymer/Laponite Nanocomposite Films Produced from Surfactant-Free Latexes using Cationic Macromolecular Reversible Addition-Fragmentation Chain Transfer Copolymers

In this work, the use of positively charged macromolecular reversible addition-fragmentation chain transfer (RAFT) copolymers (macro-RAFTs) in the synthesis of Laponite RD-based nanocomposite latex particles is described. For this purpose, two different amphiphilic copolymers composed of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and nbutyl acrylate (BA) units are investigated. In the first step, the macroRAFT is adsorbed onto Laponite, and then, in the second step, the macroRAFTmodified clay platelets are used in the emulsion copolymerization of methyl methacrylate (MMA), methyl acrylate (MA), or styrene (Sty), with BA. By acting as both coupling agents and stabilizers, the macroRAFT agents lead to the formation of partially encapsulated particles and dumbbell structures. When hydrophobic monomer mixtures that can form film are used, these morphologies result in nanocomposite films with increased stiffness, in comparison to the pure polymer matrix. As observed by dynamic mechanical analysis, the high Young's modulus level presented by the composite films in the rubbery plateau (above 100 MPa when filled with 10 wt% of clay) highlights the strong mechanical reinforcement. Such an improvement can be attributed to the formation of two percolating networks, one of homogeneously distributed and connected platelets and one of macroRAFT chains, within the polymer matrix.

Emulsifier-Free Emulsion Copolymerization of Methyl Methacrylate As a Method of Obtaining Cationic Particles for Diagnostics of Tick-Borne Encephalitis Virus

Cross-linked cationic particles 150–300 nm in diameter have been synthesized via single-stage emulsifier-free copolymerization of methyl methacrylate and 2-aminoethyl methacrylate hydrochloride in the presence of cross-linking agents (ethylene glycol dimethacrylate and N,N'-methylenebisacrylamide). Factors that enable one to control the morphology and polydispersity of the resulting particles have been determined. It has been shown that the dispersions of the particles are aggregatively stable in physiological solutions and after the sorption of biologically active molecules. The synthesized particles can be used for efficient revealing tick-borne encephalitis virus via latex agglutination reaction, with the analysis time being no longer than 10 min.

Research on factors of influencing the preparation of 2D/3D poly(methyl methacrylate) (PMMA) colloidal crystal films at the air/water interface

In this study, PMMA microspheres were synthesized by emulsifier-free emulsion copolymerization of methyl methacrylate with sodium persulfate for the fabrication of colloidal crystal films. A rapid and facile approach to fabricate 2D or 3D PMMA colloidal crystal films at the air/water interface was developed without any complex devices. During this process, the hydrophobic PMMA microspheres were dispersed into various alcohol and self-assemble at the air/water interface to form a 2D colloidal crystal film which could further be transferred onto a solid substrate layer by layer to fabricate a 3D colloidal crystal film. The orderliness of the colloidal crystal film could be influenced by types of dispersant, the ratio of the dispersant to the PMMA microspheres emulsion and the pH of colloidal suspension. In addition, the zeta potential (ζ) of PMMA microspheres could be changed with the pH of colloidal suspension. As a result, when the ratio of n-propanol to the PMMA microspheres emulsion was 1:3 and the pH was between 4 and 5, PMMA colloidal crystal films with close-packed and high-ordered structure could be easily obtained. The morphologies and microstructures of PMMA colloidal crystal films were identified by Atomic Force microscopy (AFM) and scanning electron microscope (SEM). Their transmission spectra were measured by UV-visible spectrophotometer (UV). The results also showed that the positions of Bragg diffraction peaks were shifted to a longer wavelength with the increase of the sizes of PMMA microspheres and in good agreement with particle diameters which were theoretically calculated.

Role of acrylic acid in the synthesis of core‐shell fluorine‐containing polyacrylate latex with spherical and plum blossom‐like morphology

ABSTRACTThe core‐shell fluorine‐containing polyacrylate latex was successfully synthesized by two‐stage semicontinuous emulsion copolymerization of methyl methacrylate (MMA), butylacrylate (BA), acrylic acid (AA), and dodecafluoroheptyl methacrylate (DFMA). The fluorine‐containing polyacrylate latex was characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC). The effects of AA content on monomer conversion, polymerization stability, particle size, corsslinking degree, carboxyl groups distributions (latex surface, aqueous phase or buried in latex), as well as mechanical properties and water absorption rate of latex film were investigated. The obtained fluorine‐containing polyacrylate latex exhibited core‐shell structure with a particle size of 120–150 nm. The introduction of AA was beneficial for the increase of monomer conversion and the polymerization stability, and had little effects on the mechanical property of latex film. However, the hydrophilicity of AA made the water resistance of latex film get bad. With the increase of AA content, the carboxyl groups preferred to distribute on aqueous phase, and the possibility of homogeneous nucleation increased and more oligomers particles were formed. Moreover, the oligomers would distribute to the latex and continued to grow up, making the latex morphology changed from spherical to plum blossom‐like. The core‐shell latex had two Tg corresponding to the rubber polyacrylate core and hard fluorine‐containing polyacrylate shell, and the latex film possessed excellent thermal stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42527.

One-Pot Synthesis of Poly((diethylamino)ethyl methacrylate-co-styrene)-b-poly(methyl methacrylate-co-styrene) Nanoparticles via Nitroxide-Mediated Polymerization

Poly((diethylamino)ethyl methacrylate-co-styrene)-b-poly(methyl methacrylate-co-styrene) nanoparticles were prepared by one-pot process via nitroxide-mediated polymerization (NMP). For synthesizing the first block, the SG1-mediated copolymerization of 2-(diethylamino)ethyl methacrylate (DEAEMA), a pH-sensitive monomer, and a small percentage of styrene (S) was performed in water at 90 °C using 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (VA-044) as a positively charged stabilizer and initiator. The resultant macroalkoxyamine was then employed without any purification in the protonated form as both macroinitiator and stabilizer in the same pot for the surfactant-free emulsion copolymerization of methyl methacrylate (MMA) and styrene at 90 °C, which proceeded via polymerization-induced self-assembly (PISA). Latex particles had monomodal size distribution, narrow size polydispersity, and small average size. The polymerization kinetics, the control over molar mass and molar mass distribution, the effect of the charge density on the particles size and latex stability, and the colloidal characteristics of the in situ formed block copolymer micelles were studied in detail.

Cross-linked poly(methyl methacrylate) particles with surface amino groups

Positively charged monodisperse particles have been synthesized via emulsifier-free emulsion copolymerization of methyl methacrylate with vinylformamide and ethylene glycol dimethacrylate. The effect of the cross-linking agent on the conversion of the monomers, as well as on the shape, size distribution, and surface characteristics of the obtained particles, has been determined. Addition of the cross-linking agent (5 wt %) to the reaction system has been shown to result in the formation of particles, which, after hydrolysis, have positive ζ potentials at pH 2–10.

In situ emulsion copolymerization of methyl methacrylate and butyl acrylate in the presence of SiO2 with various surface coupling densities

Poly(methyl methacrylate-co-butyl acrylate) (poly(MMA-co-BA))/SiO2 nanocomposite particles with various morphologies were prepared through in situ emulsion copolymerization of methyl methacrylate and butyl acrylate using surface 3-(methacryloyloxy) propyl trimethoxysilane (MPS)-modified SiO2 nanoparticles as nanofillers. The surface MPS-coupling density of SiO2 nanoparticles could influence the hydrophilic–lipophilic properties of SiO2 nanoparticles and subsequently influence the particle morphology of poly(MMA-co-BA)/SiO2 nanocomposite particles. With the increase of the surface MPS-coupling density of SiO2 nanoparticles, the morphology of nanocomposite particles changed from a raspberry-like one to a guava-like one. A formation mechanism of nanocomposite particles with various morphologies was proposed on the basis of the results of polymerization kinetics, particle size evolution in the process of polymerization, and particle size and morphology of the final nanocomposite particles.

Kinetic studies of semibatch emulsion copolymerization of methyl methacrylate and styrene in the presence of high intensity ultrasound and initiator

The present work deals with kinetic studies of copolymerization of methyl methacrylate and styrene using ultrasound assisted semibatch emulsion copolymerization in the presence of sodium dodecyl sulfate (emulsifier) and potassium persulfate (external initiator). The effect of temperature, acoustic intensity, initiator loading, surfactant concentration and monomer concentration on the extent of conversion has been investigated. The extent of polymerization was observed to increase with an increase in the temperature, and concentrations of initiator, monomer and surfactant. Further, the initial polymerization rate increased with an increase in the acoustic intensity from 11.2 to 23.1Wcm−2 and then it was found to decrease with a further increase to 33.80Wcm−2. The novelty of this work lies in the fact that there have been only limited kinetic studies for the approach of ultrasound assisted emulsion copolymerization. It has been also established in the present work that the formation of fine and stable monomer droplets, due to the cavitational activity at/near the interface of immiscible monomer phase and subsequent disruption by micro jets, leads to the smaller final polymer particle size and under optimized conditions, it was found to be about 40nm.

Monodispersed composite particles prepared via emulsifier‐free emulsion polymerization using waterborne polyurethane as microreactors

ABSTRACTMonodispersed polystyrene particles in submicrometer size were intriguingly prepared through emulsifier‐free batch‐seeded emulsion polymerization using nonmonodispersed waterborne polyurethane (WBPU) beads as microreactors. Different feed ratios of styrene (St)/WBPU for the preparation of composite particles were investigated, and the size–growth course was experimentally followed. The morphology and dispersity of the particles were characterized by scanning electron microscopy together with dynamic laser scattering particle size analyzer. Their inside structure was further characterized by transmission electron microscopy with ultramicrotomy combined with X‐ray photoelectron spectroscopy for the composite particles' surface analysis. The probable grafting polymerization of St from WBPU was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance instrument. The obtained composite particles were again employed as the seeds in the emulsion copolymerization of methyl methacrylate. As a result, the formed multilayered composite particles with reverse core–shell structure were also monodispersed and spherical. The mechanism of the formation of the monodispersed particles was proposed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40985.

Nitroxide-mediated surfactant-free emulsion copolymerization of methyl methacrylate and styrene using poly(2-(diethyl)aminoethyl methacrylate-co-styrene) as a stimuli-responsive macroalkoxyamine

The SG1-mediated copolymerization of 2-(diethyl)aminoethyl methacrylate (DEAEMA) and a small percentage of styrene (S) was performed.

Crosslinked monodisperse particles containing luminophore groups in shells for molecular recognition of lower alcohols

The molecular imprinting technique is used for the synthesis of monodisperse polymer particles via the seed emulsion copolymerization of methyl methacrylate, ethylene glycol dimethacrylate, and comonomers based on Nile Red. The introduction of lower alcohol templates into the reaction mixture and their removal after the synthesis lead to the formation of molecular-recognition sites in the shell that contain luminophore groups and give an optical response to the presence of methanol and ethanol in the gas phase. The particles are investigated via electron microscopy and dynamic light scattering, and their specific surface area is determined through the BET method. The kinetics of a change in the luminescence of thin films based on the particles in vapors of lower alcohols is investigated.

Polymer Architecture Control in Emulsion Polymerization via Catalytic Chain Transfer Polymerization

Hyperbranched polymers are synthesized via a cobalt(II) mediated emulsion copolymerization of methyl methacrylate and diethylene glycol dimethacrylate. The concentration of divinyl monomer and chain transfer activity have to be balanced in order to prevent gelation of the polymer particles. The physiochemical properties of the cobalt(II) complex, specifically the intrinsic chain transfer activity and the partitioning behavior, play a crucial role in governing the polymer architecture (i.e., branched versus cross-linked). Furthermore, an empirical correlation, based on the chain transfer frequency and the divinyl monomer mol fraction, is presented and validated with the results obtained in emulsion polymerization as well as with available literature data.

All-Acrylic Film-Forming Colloidal Polymer/Silica Nanocomposite Particles Prepared by Aqueous Emulsion Polymerization

The efficient synthesis of all-acrylic, film-forming, core-shell colloidal nanocomposite particles via in situ aqueous emulsion copolymerization of methyl methacrylate with n-butyl acrylate in the presence of a glycerol-functionalized ultrafine silica sol using a cationic azo initiator at 60 °C is reported. It is shown that relatively monodisperse nanocomposite particles can be produced with typical mean weight-average diameters of 140-330 nm and silica contents of up to 39 wt %. The importance of surface functionalization of the silica sol is highlighted, and it is demonstrated that systematic variation of parameters such as the initial silica sol concentration and initiator concentration affect both the mean particle diameter and the silica aggregation efficiency. The nanocomposite morphology comprises a copolymer core and a particulate silica shell, as determined by aqueous electrophoresis, X-ray photoelectron spectroscopy, and electron microscopy. Moreover, it is shown that films cast from n-butyl acrylate-rich copolymer/silica nanocomposite dispersions are significantly more transparent than those prepared from the poly(styrene-co-n-butyl acrylate)/silica nanocomposite particles reported previously. In the case of the aqueous emulsion homopolymerization of methyl methacrylate in the presence of ultrafine silica, a particle formation mechanism is proposed to account for the various experimental observations made when periodically sampling such nanocomposite syntheses at intermediate comonomer conversions.

Solvent effect on the emulsion copolymerization of methyl methacrylate and lauryl methacrylate in aqueous media

Aqueous emulsion homo- and copolymerization of lauryl methacrylate (LMA), a highly hydrophobic, almost water-insoluble monomer, is quite challenging. Due to the addition of ethanol to the aqueous phase the solvency for LMA is increased and it is possible to successfully produce LMA-methyl methacrylate (MMA) copolymer particles. The incorporation of LMA is confirmed by 1H NMR spectroscopy. Coagulation at higher ethanol content in the continuous phase could be avoided by polymeric steric stabilizers such as poly(vinyl pyrrolidone) or poly(vinyl alcohol). The conversion–time curves exhibit, independent of the stabilizer, an initially high rate where predominantly MMA is polymerized and a second period with slower rate dominated by LMA consumption as proven by 1H NMR spectroscopy and DSC data. The morphology of the copolymer particles changes with increasing ethanol content from solid sphere - like to porous. For medium PVP - stabilizer concentrations the particles possess a single pore and appear almost bowl-shaped. The large difference between the hydrodynamic and the hard sphere particle diameter indicates a high degree of swelling of the copolymer particles with the water–ethanol mixture of the continuous phase.

Nitroxide-Mediated Copolymerization of Methacrylic Acid and Sodium 4-Styrenesulfonate in Water Solution and One-Pot Synthesis of Amphiphilic Block Copolymer Nanoparticles

The SG1-mediated copolymerization of methacrylic acid and a small percentage of sodium 4-styrenesulfonate was performed in water solution at 76 °C, using BlocBuilder as an alkoxyamine initiator under acidic conditions. Unexpectedly, these conditions, which could be considered as rather unfavorable due to the instability of SG1 in acidic water, led to very good results in term of polymerization kinetics and control over polymer chain growth. It appeared that low temperature and short reaction time were the key parameters to maintain a good living character to the chains as evaluated by in situ 31P NMR. The aqueous system was then used directly as the polymerization medium for the emulsion copolymerization of methyl methacrylate and styrene performed at 90 °C. This one-pot procedure led to the synthesis of amphiphilic block copolymers that self-assembled into stable core–shell nanoparticles.

Branched and Self-Crosslinkable Poly(methyl methacrylate)s Prepared via One-Pot Synthesis in Aqueous Emulsion

An approach to the synthesis of highly branched vinyl copolymers containing thiol and C=C crosslinking groups is proposed. This method was exemplified by the emulsion copolymerization of methyl methacrylate (MMA) and 1,6-hexanediol diacrylate (HDDA) with 2-mercaptoethyl sulfide (MES) as chain transfer agent at 70°C with 4,4′-azobis(4-cyanovaleric acid) (ACVA) as the initiator. The resulting highly branched copolymers contain both thiol and acryloyl groups. The apparent Mw (by SEC) of the resulting copolymers increased with increasing ACVA concentration, whereas the pendent acryloyl and -SH groups decreased from 6.4% to 0.8% (relative to MMA units) and 45 ×10−5 to 5 × 10−5 mol/g, respectively. The copolymers of MMA could be self-crosslinked thermally or by exposure to UV irradiation. The gel fraction of the thermally treated samples decreased from 46% to 7.2%, with the increasing of ACVA in the polymer synthesis, while the gel fraction of UV irradiated samples changed only slightly around 70%.