Produce Poly Methyl Methacrylate Research Articles

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.

Evolutionary artificial neural network for temperature control in a batch polymerization reactor

The integration of artificial intelligence techniques introduces fresh perspectives in the implementation of these methods. This paper presents the combination of neural networks and evolutionary strategies to create what is known as evolutionary artificial neural networks (EANNs). In the process, the excitation function of neurons was modified to allow asexual reproduction. As a result, neurons evolved and developed significantly. The technique of a batch polymerization reactor temperature controller to produce polymethylmethacrylate (PMMA) by free radicals was compared with two different controls, such as PID and GMC, demonstrating that artificial intelligence-based controllers can be applied. These controllers provide better results than conventional controllers without creating transfer functions to the control process represented.

Plasma Oxidation Followed by Vapor Removal for Enhancing Intactness of Transferred Large-Area Graphene

Transfering large-area graphene from the metal substrate to the target substrate is crucial to its wide potential applications in electromagnetic shielding, supercapacitor, DNA sequencing, seawater desalination, wearable electronics devices, display devices for OLEDs and touch-screen. Polymethyl methacrylate assisted transfer is being widely adopted, however, this technique tends to destroy graphene and to produce polymethyl methacrylate residues on the graphene surface. Here, we reduced the damage of graphene by improving the hydrophilicity and adhesion of graphene and substrate using O2 plasma followed by heat treatment, and removed the polymethyl methacrylate residuals on the surface of graphene using hot acetone vapor. Both monolayer and multilayer graphene stacks were transferred onto the target substrate with dramatically improved surface hydrophilicity (contact angle decreased from 57.8° to 6.0°), and neither damage nor undesired residues were found. Especially, in the whole test band (400–1100 nm), all transferred graphene stacks exhibited transmittances higher than 90%. This work may bring opportunities for exploitation of large-area chemical-vapor-deposited graphene in wider transparent and ultra-thin photovoltaic devices fields.

Polymerization of N‐Vinyl Formamide in Homogeneous and Heterogeneous Media and Surfactant Free Emulsion Polymerization of MMA Using Polyvinylamine as Stabilizer

SummaryThis work considers the homogeneous aqueous phase polymerization of n‐vinyl formamide(NVF). Thus, the effect of temperature, initiator and monomer concentration in the kinetics and molar mass distribution (MMD) of the polyNVF produced was experimentally assessed. SEC‐MALS analysis was misleading because anomalous elution was found due to interaction of the polyNVF chains with the column. This was solved by analyzing the polyNVF by asymmetric‐flow field flow fractionation chromatography coupled with multi‐angle light scattering and differential refractive index, AF4/MALS/RI. The second part of this work considered the synthesis of nanoparticles based on polyNVF. Two routes were explored. In the first one the inverse microemulsion photopolymerization of NVF was attempted and polyNVF dispersions in isopar M with solids content of 18 wt% and particle sizes in the range 50–70 nm with average molar masses of several millions were obtained. In the second route PolyNVF produced in homogeneous aqueous phase was hydrolyzed to yield polyvinyl amine, PVAm. The resulting water soluble polymers were used to produce polymethyl methacrylate, PMMA, nanoparticles by surfactant free emulsion polymerization initiated by tert‐butyl hydroperoxide TBHP. Stable pH responsive PMMA cationic nanoparticles with amino functionalities in the surface were easily produced.

Manufacturing polymethyl methacrylate nanofibers as a support for enzyme immobilization

Nanofibers have a great potential for enzyme immobilization application due to their large surface area to volume ratio besides their porous structure. In this work, we produce polymethyl methacrylate (PMMA) nanofibers via electrospinning method in dimethylformamide (DMF) as solvent. Thereafter, we employ a chemical method on final PMMA nanofiberous web to covalently immobilize acetylcholinesterase (AChE) enzyme on membrane surface. Morphology and tensile properties of nanofibers are studied as first steps of characterization to make sure of obtaining a properly stable membrane for enzyme carrying application. Thereafter, the stability and activity of immobilized enzymes as two main characteristic parameters are tested and reported for different applications such as biosensor manufacturing.

Synthesis and Characterization of Polymethylmethacrylate by Using Glow Discharge Electrolysis Plasma

An approach for polymerization to produce polymethylmethacrylate (PMMA) was developed, in which the reaction was initiated by the glow discharge electrolysis (GDE) rather than chemical initiators. The highest number-average molecular weight (Mn) and the lowest polydispersity index (PDI) of the resulting polymer were 1.12 × 106 g/mol and 1.21, respectively. The following parameters such as the applied voltage, discharge time, the content of methylmethacrylate (MMA), the amount of a suspension stabilizer (polyvinyl alcohol), polymerization temperature and time were examined in detail, which could affect the conversion, molecular weight and polydispersity index. The Mn and PDI of polymer can be monitored by changing the discharge parameters and polymerization conditions. PMMA was characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), cold field emission scanning electron microscopy (FESEM), nuclear magnetic resonance (NMR) and thermogravimetric analysis (TGA). Results indicate that using the GDE technique to initiate the polymerization reaction is successful, because the product obtained has the same properties with one obtained by chemical method, for example, in chemical structure, tacticity and thermal stability. Moreover, the polymer particles for the former are smaller than the latter. The kinetic observation was that the polymerization of MMA initiated by the GDE plasma obeys the first order of reaction with an obvious induction period.

Liquid phase coating to produce controlled-release alginate microspheres

This study explored a liquid phase coating technique to produce polymethyl methacrylate (PMMA)-coated alginate microspheres. Alginate microspheres with a mean diameter of 85.6 µm were prepared using an emulsification method. The alginate microspheres, as cores, were then coated with different types of PMMA by a liquid phase coating technique. The release characteristics of these coated microspheres in simulated gastric (SGF) and intestinal (SIF) fluids and the influence of drug load on encapsulation efficiency were studied. The release of paracetamol, as a model hydrophilic drug, from the coated microspheres in SGF and SIF was greatly retarded. Release rates of Eudragit RS100-coated microspheres in SGF and SIF were similar as the rate-controlling polymer coat was insoluble in both media. Drug release from Eudragit S100-coated microspheres was more sustained in SGF than in SIF, due to the greater solubility of the coating polymer in media with pH greater than 7.0. The drug release rate was affected by the core:coat ratio. Drug release from the coated microspheres was best described by the Higuchi's square root model. The liquid phase coating technique developed offers an efficient method of coating small microspheres with markedly reduced drug loss and possible controlled drug release.