Polymerization Of Methyl Methacrylate Research Articles

Comparative Study of Antibacterial Properties of Electrospun Microfibers of Cinnamaldehyde Embedded in and Covalently Bonded to Poly (Methyl Methacrylate)

ABSTRACT In response to the food market demand regarding enhance shelf life and preserve of the food quality, active packaging technologies are being increasingly significant. To expand the use of natural compounds as antimicrobials in food packaging, we developed a new mat of microfibers containing natural antimicrobial for food wrap by linking the cinnamaldehyde (CIN) to the poly methyl methacrylate polymer (PMMA) using hydrazide-hydrazone formation protocol. The IR spectroscopy data indicated the successful synthesis of hydrazide and then corresponding hydrazone compounds. The antimicrobial microfibers were fabricated by the electrospinning of the solutions containing appropriate amounts of the cinnamaldehyde and PMMA (to prepare cinnamaldehyde embedded PMMA (CIN-em-PMMA)) or a solution of the cinnamaldehyde covalently attached PMMA (CIN-co-PMMA) at optimized conditions. The SEM images showed that the electrospun fibers without knots and with uniform diameter of 5.6 and 6.9 microns are formed. Thermogravimetric analysis indicated that the CIN-co-PMMA is more stable than CIN-em-PMMA fibers up to 150°C, however both compounds degrade at lower temperature than neat PMMA. The release of the cinnamaldehyde in aqueous media was kinetically evaluated by UV/VIS spectroscopy in an unbuffered aqueous solution. The CIN-co-PMMA exhibited more durable anti spoilage properties for preservation of highly perishable and vulnerable fruits during storage.

Light-Emitting Coordination Polymers: Stimuli-Responsive Gels, PMMA-Based Composite Films, and UV-Shielding.

Lanthanide-based light-emitting coordination polymers (CPs) and CP gels (CPGs) have significance for applications in optical systems, image processing/multiplexing, and optical sensors. In this study, we report two new luminescent CPs (EuL-CP (1) and TbL-CP (2)) and CPGs (EuL-gel (5) and TbL-gel (6)) using lanthanide(III) ions (Ln(III) = Eu(III) and Tb(III)) and 4-(4-carboxyphenyl)-2,2:6,2-terpyridine ligand (L) capable of forming stable thermoreversible gels. Probable structures of EuL-CP (1) and TbL-CP (2) and the formations of EuL-gel (5) and TbL-gel (6) are proposed based on adequate computational studies. The CPGs are stimuli-responsive and could be utilized as invisible security inks for encryption. Further, poly(methyl methacrylate) (PMMA) polymer doped with respective CPs (0.75 wt %) is found to be suitable for forming composite films with UV-shielding properties.

Cerium Oxide‐Armored Composite Latex Particles by Visible Light Emulsion Photopolymerization: From Synthesis to Film Properties

AbstractCerium dioxide (CeO2) has huge potential in many applications ranging from biochemical engineering to the coating industry. Here, the first example of visible light photo‐mediated Pickering emulsion polymerization of (meth)acrylate monomers is reported using CeO2 nanoparticles (NPs) as solid stabilizer. A ω,ω′−dicarboxylic acid diphenyl disulfide photoinitiator is anchored on the surface of the CeO2 NPs and used to initiate the emulsion polymerization of methyl methacrylate (MMA) and of MMA/n‐butyl acrylate (MMA/BA) under visible light leading to CeO2‐armored latexes. Radicals generated upon light irradiation trigger the formation of polymer chains chemically attached to the CeO2 NPs, promoting their subsequent adsorption on the latex surface. The composite films obtained from the CeO2‐armored P(MMA‐co‐BA) latexes exhibit a unique honeycomb nanostructure with the nanoceria located in the walls giving the materials excellent mechanical, anti‐UV, and photocatalytic properties.

Evaluation of the Role of [{Cu(PMDETA)}2(O2 2-)]2+ in Open-Air Photo ATRP of Methyl Methacrylate.

Herein, we report an open-air, photo accelerated atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) without employing any deoxygenating agent. Under open-air photo ATRP conditions, oxygen reversibly binds with [{Cu (PMDETA)}2(O2 2-)]2+ (1) to form the required activator, which was demonstrated by simple benchtop oxygen/nitrogen purging experiments. The binding mode of oxygen in (1) (μ(η2-η2) peroxo dicopper(II)) was investigated using UV Visible-NIR, FT-Raman and X-ray photoelectron (XPS) spectroscopic techniques. DFT studies and electrochemical measurements further support the catalytic role of (1) in open-air photo ATRP. With the synergistic involvement of Cu (II)Br2, PMDETA ligand and the intensity of light (365 nm, 4.2 mW cm-2), a well-controlled rapid polymerization of MMA under open-air condition was achieved (1.25< Đ < 1.47, 94% conversion in 200 min). The bromo chain end fidelity was exemplified by chain extension experiment, block copolymerization and MALDI-ToF analysis. Other monomers such as methyl acrylate, glycidyl methacrylate, and benzyl methacrylate were also polymerized under open-air condition with reasonable control over molecular weight and Đ. An open-air photo polymerization methodology would be fruitful for applications like photocurable printing, dental, optoelectronics, stereolithography, and protective coatings where simple but rapid photopolymerizations are desirable.

Phenacyl bromide as Norrish type I photoinitiator for the facile synthesis of chain-end functional PMMA and polystyrene

Phenacyl bromide has been explored as a new Norrish Type I photoinitiator for radically polymerizing methyl methacrylate and styrene monomers. A straightforward radical photopolymerization method using UVA light for the synthesis of chain-end functional poly(methyl methacrylate) and polystyrene has been developed. The process has been refined for both bulk and solution photopolymerizations. Chain-end functionalization was demonstrated by the formation of block-copolymers of the bromine-ended homopolymers, utilized as macroinitiators, resulting in an increase in the molecular weight of the corresponding precursor, observed by gel permeation chromatography (GPC). Block copolymerization was initiated by radicals generated at the chain-ends by a halogen-atom transfer reagent, namely, dimanganese decacarbonyl (Mn2(CO)10). This simple light-induced method is promising for the additive manufacturing field such as vat photopolymerization, stereolithography, digital light processing as it yields chain-end functional materials that can be further processed.

Transport behavior of Polymeric Methyl Methacrylate nanoplastics in saturated and unsaturated porous media: Combined influence of electrolyte and organic acids

The migration behavior of Polymeric Methyl Methacrylate (PMMA) nanoplastics in saturated porous media and unsaturated porous media is investigated under conditions of electrolytes in combination with organic acids. In the saturated porous media, the mass recovery rate of PMMA decreases with ionic strength. The inhibition effect of Ca2+ on PMMA transport is stronger than that of Na+. Under the conditions of the coexistence of electrolytes with humic acid (HA), increasing the concentration of HA does not consistently enhance PMMA migration in porous media. However, citric acid (CA) exerts solely an inhibitory effect on PMMA transport. The orthogonal analysis suggests that Ca2+ concentration is the major factor affecting PMMA transport. Extended Darjaguin-Landau-Verwe-Overbeek (XDLVO) interaction energy considering the heterogeneity of HA adsorption on PMMA is calculated to quantify the interactions of PMMA-PMMA and PMMA-quartz sand under different physiochemical conditions. In unsaturated porous media, gravity leads to the creation of dominant channels, and the shear force of water flow in porous media leads to the rapid passage of PMMA through the dominant channels. However, as the water content decreases, the recovery rate of PMMA decreases from 0.99 to 0.71. Significantly, the capillary energy of a colloid retained in a thin film or at the air-water-solid (AWS) interface is several orders of magnitude larger than the XDLVO interaction energy. Findings obtained by this study may improve the current understanding of the environmental fate of nanoplastics in subsurface environments and can provide scientific methods to assess the associated risk of nanoplastics.

Hyperbranched Organosilicon Surfactants as Emulsifiers for the Emulsion Polymerization of Methyl Methacrylate

This report is devoted to the investigation of the emulsion polymerization of methyl methacrylate in the presence of PEGylated hyperbranched polymethylethoxysiloxane as an emulsifier. It is shown that its use in the amount of 1–5 wt % affords stable 25–50% poly(methyl methacrylate) dispersions with the controlled particle sizes from 300 to 800 nm and a narrow particle size distribution.

Proton Transfer Anionic Polymerization of Methyl Methacrylate with Ligands for Dual Control of Molecular Weight and Tacticity

Proton Transfer Anionic Polymerization of Methyl Methacrylate with Ligands for Dual Control of Molecular Weight and Tacticity

Diffusion and Exchange Kinetics of Microparticle Formulations by Spatial Fourier Transform Fluorescence Recovery after Photobleaching with Patterned Illumination.

The mechanism of active pharmaceutical ingredient (API) mobility during release in microparticle formulation was investigated using periodically structured illumination combined with spatial Fourier transform fluorescence recovery after photobleaching (FT-FRAP). FT-FRAP applies structured photobleaching across a given field of view, allowing for the monitoring of molecular mobility through the analysis of recovery patterns in the FT domain. Encoding molecular mobility in the FT domain offers several advantages, including improved signal-to-noise ratio, simplified mathematical calculations, reduced sampling requirements, compatibility with multiphoton microscopy for imaging API molecules within the formulations, and the ability to distinguish between exchange and diffusion processes. To prepare microparticles for FT-FRAP analysis, a homogeneous mixture of dipyridamole and pH-independent methyl methacrylate polymer (Eudragit RS and RL) was processed using laminar jet breakup induced by vibration in a frequency-driven encapsulator. The encapsulated microparticles were characterized based on particle size distribution, encapsulation efficiency, batch size, and morphology. Utilizing FT-FRAP, the internal diffusion and exchange molecular mobility within RL and RS microparticles were discriminated and quantified. Theoretical modeling of exchange- and diffusion-controlled release revealed that both RL and RS microparticles exhibited similar exchange decay rates, but RL displayed a significantly higher diffusion coefficient. This difference in diffusion within RL and RS microparticles was correlated with their macroscopic dissolution performance.

Confining CsPbI3 perovskite in metal organic framework (MOF-545) as stable composite photocatalyst for efficient oxygen-tolerant NIR light-driven atom transfer radical polymerization

Zirconium-porphyrin metal-organic framework (MOF-545) encapsulated all inorganic iodide perovskite (CsPbI3) composite (CsPbI3@MOF-545) is used as highly efficient photocatalyst to catalyze NIR light induced atom transfer radical polymerization (ATRP). The combination of CsPbI3 and MOF-545 leads to a synergistic effect with enhanced photoinduced carrier separation and light absorption performance in the composite photocatalyst. The constructed CsPbI3@MOF-545(10 %) can efficiently catalyze the conversion more than 90 % of various monomers under 810 nm NIR light irradiation. Strong oxygen-resistance has been confirmed in the CsPbI3@MOF-545(10 %) catalyzed photo-ATRP system. In a large-volume photo-ATRP system (100 mL), the polymerization of methyl methacrylate (MMA) achieved a conversion over 90 % in 10 h using NIR light in air. The success of chain extension and block polymerization indicates good end-chain fidelity for the synthesized polymers. The composite photocatalyst still displays high photocatalytic activity for the synthesis of polymers with controllable dispersity after seven photopolymerization cycles, demonstrating its promising potential for practical applications.

Water‐Soluble, Spin‐Cast‐Based Crystalline Poly(Methacrylic Acid) Film as a Reversible Li‐Ion Battery Anode

Poly(methyl methacrylate) (PMMA) polymer anodes are proposed as potential reversible anode materials for lithium‐ion batteries (LIBs) owing to their simple thin‐film formation process and cost‐effectiveness. Nevertheless, challenges such as the use of toxic aprotic solvents and the irreversible consumption of Li ions during the initial cycle need to be addressed to improve their performance. Herein, a water‐soluble poly(methacrylic acid) (PMAA) polymer processed using a simple spin‐casting method as a reversible LIB anode is presented. Unlike the PMMA anode, the conjugated carbonyl groups of the crystalline PMAA polymer readily form a chain backbone during ex situ thermal annealing, demonstrating a reversible capacity. The mechanism underlying the superior electrochemical characteristics of the PMAA anode is revealed using grazing incidence X‐ray diffraction and theoretical calculations. In particular, the highly crystalline cyclic anhydride PMAA polymer induced by thermal annealing shows enhanced interactions between Li ions and CO groups during operation, resulting in improved electrochemical properties. The resulting crystalline cyclic anhydride PMAA anode achieves a capacity of ≈427.7 mAh g−1 and retains a reversible specific capacity of 156 mAh g−1 after 500 cycles, indicating that it is a promising polymeric anode for next‐generation LIBs.

One Reaction: Two Types of Mechanism-SARA-ATRP and SET-LRP-for MMA Polymerization in the Presence of PVC.

This study presents for the first time the polymerization of methyl methacrylate (MMA) in the presence of poly(vinyl chloride) (PVC) that takes place by both SARA-ATRP and SET-LRP mechanisms. The two types of polymerizations that occur in the system are PMMA grafting to the PVC backbone and the formation of a new PMMA polymer, both occurring in the presence of a Cu0wire. The polymerizations were controlled as confirmed by the molecular weight evolution, polymerization kinetics, and variations in the dispersity value. The MMA polymerization in the presence of PVC at 60 and 70 °C leads to the formation of two polymer species characterized by an increase in the molecular weight with the conversion and a narrowing of the dispersity value with the reaction progress. To increase the degree of control over the polymerization, the same reaction was performed at room temperature, which allowed us to highlight the presence of the SARA-ATRP and SET-LRP mechanisms via subsequent polymer chain extensions. The results demonstrated that PMMA grafting on PVC polymers follows a SARA-ATRP mechanism, while the formation of a PMMA homopolymer entails a SET-LRP process. The influence of solvent nature on the polymerization reaction was studied by performing the grafting of N-isopropylacrylamide (NIPAM) onto the surface of PVC particles in aqueous media in the presence and in the absence of CuCl2. The polymerization reactions and the obtained materials were studied by gel permeation chromatography (GPC), 1H NMR, DMA, scanning electron microscopy (SEM), and atomic force microscopy (AFM).

Bioderived Thiol-Ene Emulsion Polymerization for Hybrid Latex Particles.

The thiol-ene emulsion polymerization of three dienes synthesized from bioderived compounds, and subsequent preparation of core-shell polymer latexes, is reported. Levoglucosan (LGA), levogucosenone (LGO) and isosorbide were first modified with 4-pentenoic acid to install polymerizable groups. These monomers were used along with a dithiol to prepare poly(thioether) particles via ab initio emulsion polymerization using potassium persulfate as initiator and sodium dodecyl sulfate as surfactant. The structure of the diene significantly influenced the size of the resulting polymer latex particles. Given their low glass transition temperature, the LGA-derived poly(thioether) particles were used as a seed for the seeded emulsion polymerization of either styrene or methyl methacrylate. Core-shell latex particles with a high Tg core and a low Tg bioderived shell were formed, as verified by electron microscopy and in agreement with theoretical predictions of the equilibrium particle morphology based on the interfacial tensions of each particle phase.

Polymer-Ion Interaction Prompted Quasi-Solid Electrolyte for Room-Temperature High-Performance Lithium-Ion Batteries.

Lithium-ion batteries using quasi-solid gel electrolytes (QSEs) have gained increasing interest due to their enhanced safety features. However, their commercial viability is hindered by low ionic conductivity and poor solid-solid contact interfaces. In this study, a QSE synthesized by in situ polymerizing methyl methacrylate (MMA) in 1,2-dimethoxyethane (DME)-based electrolyte is introduced, which exhibits remarkable performance in high-loading graphite||LiNi0.8Co0.1Mn0.1O2 (NCM811) pouch cells. Owing to the unique solvent-lacking solvation structure, the graphite exfoliation caused by the well-known solvent co-intercalation is prohibited, and this unprecedented phenomenon is found to be universal for other graphite-unfriendly solvents. The high ionic conductivity and great interfacial contact provided by DME enable the quasi-solid graphite||NCM811 pouch cell to demonstrate superior C-rate capability even at a high cathode mass loading (17.5mgcm-2), surpassing liquid carbonate electrolyte cells. Meanwhile, the optimized QSE based on carbonates exhibits excellent cycle life (92.4% capacity retention after 1700 cycles at 0.5C/0.5C) and reliable safety under harsh conditions. It also outperforms liquid electrolytes in other high-energy-density batteries with larger volume change. These findings elucidate the polymer's pivotal role in QSEs, offering new insights for advancing quasi-solid-state battery commercialization.

Functionalized Polyisobutylene and Polyisobutylene‐Based Block Copolymers by Mechanistic Transformation from Cationic to Radical Process

AbstractThe strategy for the preparation of polyisobutylene‐based block copolymers via mechanistic transformation from cationic to radical polymerization is reported. This strategy involves the synthesis of 2‐bromo‐2‐methylpropanoyl‐terminated difunctional polyisobutylene macroinitiator (BiBB‐PIB‐BiBB) via consecutive cationic polymerization, in situ preparation of hydroxyl‐terminated polyisobutylene and its acylation by 2‐bromo‐2‐methylpropanoyl bromide. The Mn2(CO)10−triggered photo‐induced radical polymerization of styrene in bulk using this macroinitiator leads to the formation of multiblock copolymer, while predominantly triblock copolymer is generated during the polymerization of methyl methacrylate. The possibility to functionalize the polyisobutylene by pyrene via photo‐induced radical addition of 1‐bromomethyl pyrene in the presence of Mn2(CO)10 is also demonstrated in this work.

Improving the mechanical, spectroscopic and laser ablation characteristics of UDMA-MMA copolymers using a titanocene photoinitiator

We have shown that the Irgacure 784 titanocene photoinitiator can be advantageously used to improve the light absorption, mechanical and nanosecond-regime laser ablation properties of urethane dimethacrylate (UDMA)-methyl methacrylate (MMA) polymer blends with photopolymerization using curing with green (520–525 nm) light. The hardness was found to be significantly higher (0.25–0.29 GPa) than that of other UDMA polymer blends photopolymerized using other initiator systems. The established 48–63 % degree of conversion is also comparable to that of similar other blends and is useful in many applications. The laser ablation and laser-induced breakdown spectroscopy (LIBS) properties of these polymers were studied at 266 and 532 nm laser wavelengths. The polymers showed consistently good laser ablation characteristics (reproducible, well-defined, shallow craters) at 266 nm wavelength, whereas at 532 nm, extensive carbonization and strong photothermal effects were observed. LIBS spectra of the blend shows lines of C, H, O, N and Ti as well as C2 and CN bands, but provide many spectral windows for interference-free analytical measurements. Our findings indicate that UDMA-MMA polymer blends can be good candidates as target matrices for laser ablation-based measurements in the UV or Vis range, in applications like analytical spectroscopy or laser-initiated fusion research.

Modeling of a solution polymerization reactor operating in semi-batch mode for polymethyl methacrylate production

The severe consequences of thermal runaways, make process optimization of paramount importance for free radical polymerization reactors, in order to maximize in an integrated way their safety and productivity. Generally, this optimization is performed by simulation, for the sake of safety and cost. Today, the literature contains several models of free radical polymerization reactors in general; and methyl methacrylate (MMA) polymerization reactors, in particular. Although, MMA polymerization is commonly performed in semi-batch reactors at industrial level, most of the available models focus on batch reactors; while, the semi-batch reactor models are much scarcer. In this work, a model of a MMA solution polymerization batch reactor was modified in order to generalize it to semi-batch operation. The developed semi-batch model was used here for studying the effect of different operation conditions (feeding flow rate, initiator load, monomer initial load, and reactor temperature) on the quality characteristics of the produced polymer and on the safety and productivity of the polymerization reactor. The developed model can be used to optimize the operation conditions of a semi-batch reactor so that the final product quality meets the application requirements, while maintaining the reactor within its safe-operation envelope, and maximizing its productivity.

Synthesis of multi-stimuli-responsive flocculants using reversible addition-fragmentation chain transfer polymerization: Investigating the performance and mechanism of kaolin coagulation

Coumarin-containing amphiphilic block copolymers with different compositions, as a new class of pH- and photo-responsive flocculants, were synthesized through reversible addition-fragmentation chain transfer polymerization of dimethyl aminoethyl methacrylate (DMAEMA), methyl methacrylate, and 7-acryloyloxy 4-methylcoumarin. Proton nuclear magnetic resonance spectroscopy was used to study the structure and composition of the copolymers. Zeta potential results show that the copolymers are applicable as amphoteric flocculants. The optimal flocculant concentration was calculated using the Jar analysis for kaolin flocculation, and the results show that the flocculation dependence on the flocculent concentration decreases with increasing its molecular weight. The dominance of charge neutralization in the flocculants with lower molecular weights and the dominance of adsorption bridging and hydrophobic association in the flocculants with higher molecular weights were indicated. These results are in agreement with the rheological data. To investigate the governing mechanism more precisely, the flocculation rate was calculated using turbidity measurements at different pH values over time. The highest final flocculation rate (99.25 %) corresponds to pH 4.5, which caused by the protonation of the amine groups of the DMAEMA repeating units. The dependence of settling rate on pH indicates the pH-dependent performance of the flocculants. Finally, fluorescence microscopy image of the flocculants shows its proper functioning of in the vicinity of kaolin, which has a promising industrial application.

Design and Construction of Highly Luminescent Transparent Woody Materials Exhibiting Unique Fluorescence-Enhanced Staining Effects for Visualization of Intrinsic Microporous Networks.

Luminescent wood materials are an emerging class of biomass hybrid host materials owing to the hierarchical porous structure and functionalization versatility. The fluorescence properties are largely dependent on exogenous fluorophores, which are, however, often plagued by notorious aggregation effects. In this work, an efficient strategy for the preparation of luminescent transparent wood materials is developed by incorporating tetraphenylethylene-derived aggregation-induced emission (AIE)-active fluorophores during a delignification-backfill transparency process. These wood hybrids showed unexpected luminescence enhancement that significantly increased the fluorescence quantum yield of the fluorophores up to 99%, much higher than that of the fluorophores in other states such as crystalline solids or doped in a polymer substrate. Mechanistic investigations reveal that in situ polymerization of prepolymerized methyl methacrylate in delignified microporous wood frames produces high molecular weight ordered PMMA polymers, resulting in a rigid molecular environment that improves the luminescence efficiency of TPE-based fluorophores at the interfaces of PMMA polymer and cell walls. By confocal laser scanning microscopy (CLSM), this excellent fluorescence staining capability was furthermore utilized to visualize the intrinsic porous network of wood in three dimensions over a large volume with submicrometer resolution, thus providing an alternative approach to the study of structure-function relationships in such wood hybrids.

Facile fabrication of polyurethane/poly(methyl methacrylate) semi‐interpenetrating polymer networks for enhanced mechanical and thermal properties

AbstractThe primary objective of this research is to fabricate semi‐interpenetrating polymer networks (semi‐IPNs) via in‐situ polymerization of methyl methacrylate (MMA) within a polyurethane (PU) framework. To produce polymethyl methacrylate (PMMA) from MMA in the PU matrix, solution polymerization was utilized in the following weight ratios: 30/70, 50/50, 70/30, and 90/10. The effective formation of semi‐IPNs of PU/PMMA was confirmed by several techniques. Fourier transform infrared (FTIR) proves that no new chemical bonds formed between the semi‐IPNs, and only physical interactions were present, and X‐ray diffraction (XRD) techniques tell about the amorphous nature of these semi‐IPNs. The field emission scanning electron microscope (FESEM) and atomic force microscope (AFM) were utilized to examine the morphology of PU/PMMA semi‐IPNs. In contrast to alternative semi‐IPNs, 70/30 and 90/10 PU/PMMA exhibit a uniform morphology devoid of phase separation. Furthermore, the significant thermal stability and transitions of these semi‐IPNs were assessed using a thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Additionally, the mechanical analysis indicates that among the different percentages of PU/PMMA, 70/30 PU/PMMA exhibits the highest tensile strength of approximately 50.5 MPa. The observed enhancement in mechanical strength can be attributed to interpenetrating networks (IPNs) formed between the constituents. The synthesized PU/PMMA semi‐IPNs have potential in various fields, including medical devices, automotive components, sports, and other advanced applications.