Methyl Methacrylate Content Research Articles

Cytotoxicity of acrylic based resin compounds in a human gingival fibroblast cell line

In vitro cytotoxicity testing of dental acrylic resins is fundamental to establish clinical safety limits, requiring suitable cell models that closely simulate physiological processes. This study's main aim is to evaluate the viability of an untransformed human gingival fibroblast cell line, as an oral cell model for acrylic resin cytotoxicity tests. For this purpose, cell viability was compared to a control cell line (Chinese hamster lung fibroblast), following exposure to increasing concentrations of methyl methacrylate and formaldehyde (acrylic resins’ leachable compounds). Additionally, because of the volatile nature of these compounds and their harmful effects on the respiratory tract, a human fetal lung fibroblast line was also tested. Two-way ANOVA of generated data (p<0.05) showed that all cell types are significantly affected in a dose dependent manner by these chemicals. Further characterization of the human gingival fibroblast line shall be addressed in future biocompatibility studies.

Properties of UV-curable solvent-free pressure sensitive adhesive

In this study, the effects of methyl methacrylate (MMA), trimethylolpropane triacrylate (TMPTA), difunctional silicone urethane acrylate oligomer, and UV-dose on the adhesive properties of UV-curable pressure-sensitive adhesives (PSAs) were investigated, for further optimizing the adhesive properties to meet the requirements on high holding power and low peel strength. The results illustrated that increasing the MMA content decreased the peel strength and improved the holding power. The variation of TMPTA content from 1 to 10 wt% significantly enhanced the holding power from 1 h to above 120 h. The gel fraction increased with increasing TMPTA content. This increment was caused by the cross-linking of TMPTA after UV exposure. The peel strength of UV-curable PSAs was reduced to zero when oligomer content was more than 40 wt%, whereas the holding power was significantly enhanced from 5 h to above 120 h as the oligomer content increased up to 70 wt%. When the UV-dose increased, the peel strength decreased and the holding power increased. Therefore, UV-curable PSAs with very low peel strength and high holding power above 120 h were successfully synthesized and they possessed desirable features which could be fabricated to meet the specific requirements for industrial applications.

Mechanical performance, water absorption behavior and biodegradability of poly(methyl methacrylate)-modified starch/SBR biocomposites

Natural corn starch was modified by surface grafting with poly(methyl methacrylate) (PMMA) through emulsion copolymerization and then compounded with styrene-butadiene rubber (SBR) latex in order to prepare PMMA-modified starch/SBR biocomposites. The effect of methyl methacrylate (MMA) and starch concentration on the mechanical properties, morphology, toluene swelling behavior, water absorption behavior and biodegradabil- ity of PMMA-modified starch/SBR biocomposites was investigated. Results showed that the optimum mechanical properties were achieved when the concentrations of MMA and starch were 10 and 30 phr, respectively, which could be also confirmed through the observations from FE-SEM micrographs and equilibrium welling test. Guth-Gold and Halpin-Tsai models were employed to predict the modulus of PMMA-modified starch/SBR biocomposites. Halpin- Tsai model was better fitted with the experimentally measured data than Guth-Gold model. The water absorption ratio of PMMA-modified starch/SBR biocomposites was strongly influenced by the immersion time and the starch concentration, which further caused a significant effect on the biodegradability of biocomposites.

Síntese e caracterização de copolímeros reticulados à base de estireno, divinilbenzeno e metacrilato de metila com propriedades magnéticas

Neste trabalho, foram sintetizados copolímeros à base de estireno (STY), divinilbenzeno (DVB) e metacrilato de metila (MMA) com propriedades magnéticas pela técnica de polimerização em suspensão. Os copolímeros foram caracterizados quanto a sua morfologia, ao teor de ferro incorporado, a densidade aparente, a distribuição de tamanho de partículas e as suas propriedades magnéticas. Foi avaliado o efeito da concentração de MMA sobre as características das partículas poliméricas obtidas. Copolímeros que não utilizaram MMA foram, em geral, os que apresentaram maior incorporação de ferro e melhor controle morfológico. Quando a temperatura foi alterada de 80 ºC para 70 ºC e a velocidade de agitação de 480 rpm para 360 rpm, houve aumento no teor de ferro incorporado nas partículas poliméricas.

Possibilities for reducing tractor engine friction losses at cold start using an ultrasonic irradiation technique

Redox copolymerization of N-vinyl-2-pyrrolidone (NVP) with methyl methacrylate (MMA) was carried out using titanium(III)-- dimethylglyoxime [Ti(III)-DMG] redox initiator in aqueous sulfuric acid-alcohol media. The resulting copolymer was characterized by FTIR, 1H-NMR, and 13C-NMR spectroscopic methods and elemental analysis. Thermal properties of the copolymer were determined by differential scanning calorimetric technique and thermogravimetric analysis. The reactivity ratios of the monomers were computed by Fineman-Ross, Kelen-Tudos, and extended Kelen-Tudos methods at lower conversion. The reactivity ratios obtained r1 (MMA) 1.69 and r2 (NVP) 0.03 showed richer content of MMA than NVP in the copolymer having extreme ideal behavior. The distribution of monomer sequence along the copolymer chain was calculated using a statistical method based on reactivity ratios. Ti(III)-DMG redox initiator showed increased addition of NVP to MMA during copolymerization.

Synthesis of TDI-Polyurethane/Polyacrylate Composite Emulsion by Solvent-free Method and Performances of the Latex Film

Using the blend of methyl methacrylate (MMA) and butyl acrylate (BA) instead of acetone as a diluent, hydroxyethyl acrylate to terminate the ends of prepolymer, and emulsifying at 85°C, TDI-polyurethane/polyacrylate (TDI-PU/PA) composite emulsion was prepared using toluene diisocyanate (TDI), polypropylene glycol (PPG), 1,6-hexanediol (HDO) and dimethylol propionic acid (DMPA) on the basis of solvent-free method. The chain structure and polymerization progress were confirmed by the analysis of Fourier transform infrared spectroscopy. The desired emulsion could be synthesized when the molar ratio of NCO group in TDI to total OH groups in PPG, DMPA and HDO was 1.18, triethylamine (TEA) and water were added simultaneously during the emulsification, and acrylic monomers were initiated by potassium persulfate at 80°C. It was found that tensile strength, pendulum hardness of the latex film cast from composite emulsion increased and water resistance became better with increasing the content of MMA. Compared with IPDI-PU/PA, TDI-PU/PA composite emulsion not only had a low cost, but also the maximum of titanium pigment added into the emulsion could be increased double, which introduced a distinct increase for the hardness and the covering power of the latex film.

Influence of Acrylic Resin Polymerization Methods on Residual Monomer Release

The aim of this study was to quantify and compare the amount of methyl methacrylate (MMA) monomer released from three different denture base acrylic material processed by different polymerization methods and storage conditions. Microwave-cured, conventional heat and injection-technique acrylic polymerized materials were stored in neutral (pH = 7) and acidic (pH = 4.5) artificial saliva for 24 hours at the room temperature, separately. The residual MMA content was determined by high performance liquid chromatography (HPLC). The MMA leaching from resins showed that microwave-cured material has lower residual MMA leach compared both conventional and injection-technique on neutral saliva storage conditions. The all data's exhibited higher MMA release into an acidic saliva environment than neutral artificial saliva and there were no significant differences between the materials groups on acidic saliva storage conditions. Microwave polymerization method might has some advantages on reducing release of MMA concentration and may contributory effect upon polymerization reaction on neutral pH storage condition, therefore methods of polymerization should be considered as amount of monomer release.

Solubility and diffusivity of carbon dioxide in St-MMA copolymers

The present study focuses on synthesizing styrene-methylmethacrylate (St-MMA) copolymer particles in a batch reactor using suspension polymerization process at different copolymer compositions. Also for further comparisons, the neat polystyrene (PS) and polymethyl methacrylate (PMMA) were synthesized by the same method. The solubility and diffusivity of supercritical carbon dioxide (scCO2) into the synthesized copolymers at two temperatures (393 and 423)K and pressures in the range from (5 to 12)MPa were measured by a magnetic suspension balance. The Sanchez–Lacombe (SL) equation of state was used to estimate the swelling effect of CO2 on copolymers. The results showed that the solubility and diffusivity of CO2 increased with increasing of CO2 pressure and slightly improved with methyl methacrylate (MMA) content in copolymer. As well as the solubility of CO2 in samples decreased with temperature increment and contrary behavior was observed for diffusivity. Fujita, Maeda and Paul’s diffusion models were combined to estimate the diffusion coefficients for the copolymers and neat polymers.

Mechanochemical polymerization of methyl methacrylate initiated by the grinding of quartz in an n-heptane solvent

Abstract The information on mechanoradicals produced by grinding quartz in an n-heptane solvent was examined by means of electron spin resonance spectroscopy (ESR). The wet grinding of quartz was carried out by using a vibrating ball mill with a laboratory scale. The data of the ESR measurement revealed that E′ center radicals ( Si ) primarily produced from ground quartz in an n-heptane solvent and that the concentration of the mechanoradicals was approximately proportional to the specific surface area of ground quartz. The polymerization of methyl methacrylate (MMA) mechanochemically initiated by the grinding of quartz in the mixture solvent of n-heptane and MMA was also attempted by using the vibrating ball mill. The effect of the concentration of MMA monomer on the polymerization was investigated. As a result, the existence of the induction period to be observed well in radical polymerization was confirmed in all of the concentrations of MMA. It was found that the conversion of MMA increased with the decrease of MMA monomer and that the largest polymer yield was obtained at the concentration where the amount of monomer and solvent was the same in volume.

Strength development characteristics of UP-MMA based polymer concrete with different curing temperature

In this study, the effects of curing temperature, age, and unsaturated polyester (UP)-methyl methacrylate (MMA) ratio on the strength development characteristics of UP-MMA based polymer concrete are investigated. This study distinguishes itself from previous research in that MMA monomer was used to adjust the viscosity of UP resin, instead of styrene monomer. The result showed that as the curing temperature decreased from 20 to −20°C, the strengths were reduced by 32.8% on average. Also, research revealed that the UP-MMA based polymer concrete significantly develops its strengths within the first 6h, and the average strength at 72h was 86.6% of the strength at 168h. As the MMA content increases, the strengths of UP-MMA based polymer concrete tended to decrease. However, the effect of MMA on the strength reduction was less significant than that of curing temperature. Also, this study proposes a strength predictive model based on the maturity concept. The result of regression analysis between the measured strengths and computed maturity yielded high coefficients of determination of 0.91–0.97, validating the applicability of the maturity model suggested by Ohama. The findings of this study could be utilized as important data for field applications as well as manufacturing of precast products.

Design and control of soap-free hydrophilic-hydrophobic core-shell latex particles with high carboxyl content in the core of the particles

Soap-free hydrophilic-hydrophobic core-shell latex particles with high carboxyl content in the core of the particles were synthesized via the seeded emulsion polymerization using methyl methacrylate (MMA), butyl acrylate (BA), methacrylic acid (MAA), styrene (St) and ethylene glycol dimethacrylate (EGDMA) as monomers, and the influences of MMA content used in the core preparation on polymerization, particle size and morphology were investigated by transmission electron microscopy, dynamic light scattering and conductometric titration. The results showed that the seeded emulsion polymerization could be carried out smoothly using “starved monomer feeding process” when MAA content in the core preparation was equal to or less than 24 wt%, and the encapsulating efficiency of the hydrophilic P(MMA-BA-MAA-EGDMA) core with the hydrophobic PSt shell decreased with the increase in MAA content. When an interlayer of P(MMA-MAA-St) with moderate polarity was inserted between the P(MMA-BA-MAA-EGDMA) core and the PSt shell, well designed soap-free hydrophilic-hydrophobic core-shell latex particles with 24 wt% MAA content in the core preparation were obtained.

Thermal-Oxidative Aging Resistance and Water Absorption of Natural Rubber Latex/Methyl Methacrylate-Grafted-Natural Rubber Latex Blends

Abstract. The natural rubber latex (NRL) concentrate was mixed with 10～50 parts per hundred rubber (phr) of methyl methacrylate-grafted-natural rubber latex having a methyl methacrylate content of 49% (MGL49), prevulcanized, and then cast to obtain prevulcanized NRL/MGL49 films. The leached films of prevulcanized NRL/MGL49 were aged in an hot-air oven for comparison of the mechanical properties before and after aging, whereas the thermal decomposition of these films in an atmosphere of air was carried out in a thermo-gravimetric analyzer, and the films were also immersed into water to obtain water absorption. Results showed that the incorporation of MGL49 improved the thermal-oxidative aging resistance of natural rubber latex film when the MGL49 content was less than 50 phr, the water absorption increased with the increment of MGL49 content, and the NRL/MGL49 film containing 10phr of MGL 49 has a best thermal-oxidative stability and highest water absorption also.

Effect of Methyl Methacrylate Content in Carbon Black Filled Natural Rubber Compounds

Natural rubber-grafted-poly(methyl methacrylate) containing 30 and 50 percent of methyl methacrylate (MMA) monomer per 100 parts by weight of the dry rubber content denoted as NR-g-PMMA 30 and NR-g-PMMA 50, respectively were prepared via emulsion polymerisation technique. The occurrences of graft copolymerisation of PMMA onto NR were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Fourier Transform Infrared (FTIR) following purifications. The reinforcement of rubber by fillers is of great practical and technical importance. Thus, these fillers are added to rubber formulations to optimize the properties to meet a given application or set of performance parameters. In this study, the effect of carbon black in NR-g-PMMA 30 and NR-g-PMMA 50 rubber compounds were evaluated. Our results demonstrated that tensile strength, elongation at break and compression set reduced, while the hardness and solvent resistance increased in the presence of carbon black filler in comparison to the unfilled compound.

Diffusion and solubility of commercial poly(methyl methacrylate) denture base material modified with dimethyl itaconate and di‐n‐butyl itaconate during water absorption/desorption cycles

AbstractThis study evaluated the water absorption, solubility, kinetics of water diffusion and residual monomer content of commercial poly(methyl methacrylate) (PMMA) denture base material modified with dimethyl itaconate (DMI) and di‐n‐butyl itaconate (DBI). Water absorption and solubility were measured gravimetrically while the residual monomer content was analysed using high‐performance liquid chromatography with ultraviolet detection. It was found that the addition of di‐n‐alkyl itaconates significantly decreases the residual methyl methacrylate (MMA) content in the polymerized material. Maximum uptake (M∞) and loss (M′∞), and diffusion coefficients for absorption (Da) and desorption (Dd) of water through all materials were established. M∞ shows a linear decrease with increasing amount of itaconate in the system while Da shows a linear increase with increasing amount of itaconate, both of these effects being more pronounced when DBI is present compared to DMI. M∞ is a linear function of the value of Hoy's solubility parameter. The reduction in residual MMA promoted by addition of a small amount of di‐n‐alkyl itaconates can improve the applicative properties and biocompatibility of the PMMA denture base material. Also, it is shown that modification of the denture base material with di‐n‐alkyl itaconates can enable precise control of water absorption in the system. Copyright © 2012 Society of Chemical Industry

Inhalation study of polymethyl methacrylate following radiologist exposure during percutaneous vertebroplasty

To assess the atmospheric concentrations of methyl methacrylate (MMA) vapors during percutaneous vertebroplasty for the interventional radiologist and the other operating room staff. During percutaneous vertebroplasty, a polymethyl methacrylate (PMMA) mixture (about 20 mL) was prepared with a mixing system in a normally ventilated room. Atmospheric concentrations of MMA vapors were measured by a gas absorbent badge for individual exposure (GABIE) passive sampler attached to the surgical gowns of the interventional radiologist and the other operating room staff over a period of 460 min. Active sampling was performed over 15 min with an individual pump placed near the breathing zone of the radiologist. MMA vapor concentrations were then measured using gas chromatography and activated charcoal tubes. Mean MMA vapor concentrations measured by the GABIEs over the period of 460 min were 0.51 parts per million (ppm) for the radiologist and 0.22 ppm for the other operating room staff. The emission peaks measured by using charcoal tubes over 15 min were 3.7 ppm. MMA vapor concentrations during percutaneous vertebroplasty were well below the recommended maximum exposure of 100 ppm over the course of an 8-h workday.

Coating performances of copolymers from a novel palm oil‐based macromer and methyl methacrylate

PurposeThe purpose of this paper is to develop hybrid copolymers through the copolymerisation of a novel low molecular weight oleic acid‐based macromer with methyl methacrylate (MMA), with the aim of combining the good properties of alkyd and acrylic binders.Design/methodology/approachThe macromer was synthesised from phthalic anhydride, oleic acid and glycerol. It was copolymerised with MMA using a free radical initiator. The ratio of the macromer and MMA was varied and the glass transition temperature, molecular weight, thermal stability, and film properties of the copolymers were characterised.FindingsUnder similar conditions of temperature and reaction time, the lower macromer to MMA ratio has led to faster polymerisation rate, higher molecular weight and higher Tg of the copolymer. Generally, all the coatings showed excellent adhesion properties, while the coatings with the higher content of MMA exhibited better alkali and water resistance.Research limitations/implicationsThe macromer used in the present context was synthesised from oleic acid and glycerol supplied by a local palm oil oleochemicals manufacturer. Presumably the same raw materials from other vegetable oils could also be used. In addition, the macromer structure could be changed by varying the formulation so that it would have different molecular weight and functionality.Practical implicationsThe method has managed to combine the properties of alkyd and acrylic, resulting in coatings that exhibit good mechanical and chemical properties, fast physical drying as well as excellent adhesion.Originality/valueOleic acid and glycerol are palm oil derivatives which are from natural resources and are sustainable raw materials. Although the macromer by itself cannot air‐dry due low iodine value, this could be overcome through copolymerisation with methyl methacrylate to find numerous applications in surface coating.

Thermomechanical and fractographic behavior of poly (HDDA‐co‐MMA): a study for its application in microcantilever sensors

Polymer‐based materials have drawn significant attention lately for their application in design and fabrication of thermomechanically stable highly sensitive three‐dimensional (3D) micromechanical sensor structures. Among these materials, 1,6 Hexane diol diacrylate (HDDA) has been extensively explored in laser‐based 3D microfabrication by microstereolithography. The thermomechanical properties of poly HDDA are important for their end use application in microcantilever‐based sensors. The present work explores the optimization of these properties by copolymerization of HDDA and methyl methacrylate (MMA) for these specific applications. The dynamic mechanical analysis, thermal expansion and mechanical studies were carried out for different compositions of poly (HDDA‐co‐MMA). An increase in MMA content in the copolymer matrix resulted in the enhancement of the thermomechanical stability. The variations of thermal expansion coefficient (CTE) for different compositions were also studied. Microhardness, uniaxial tensile, and flexural tests along with Poisson's ratio were determined to understand the mechanical properties of these compositions. The scanning electron micrographs of fractured surfaces of all the compositions were analyzed to understand the fracture mechanism of various compositions of this copolymer. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Grafting of LiAMPS on ethyl cellulose: a route to the fabrication of superior quality polyelectrolyte gels for rechargeable Lithium ion batteries

New types of semi-interpenetrating polymer gel electrolytes with high conductivity as well as strength for use in rechargeable Lithium polymer batteries are synthesized. Single ion conducting polyelectrolyte gels are made by first synthesizing grafted linear chains of Lithium salt of 2-acrylamido-2-methylpropane sulphonic acid on ethyl cellulose (EC) using free radical initiator azobis (cyclohexanecarbonitrile) in dimethyl acetamide solvent, then copolymerizing methyl methacrylate (MMA) and a crosslinking agent ethyleneglycol dimethacrylate to form semi-interpenetrating network. The effect of concentrations of EC and MMA on electrical conductivity and mechanical strength of gels are determined.

Copolymerization of N-Vinyl pyrrolidone with methyl methacrylate by Ti(III)-DMG redox initiator

Redox copolymerization of N-vinyl-2-pyrrolidone (NVP) with methyl methacrylate (MMA) was carried out using titanium(III)-- dimethylglyoxime [Ti(III)-DMG] redox initiator in aqueous sulfuric acid-alcohol media. The resulting copolymer was characterized by FTIR, ^1H-NMR, and ^{13}C-NMR spectroscopic methods and elemental analysis. Thermal properties of the copolymer were determined by differential scanning calorimetric technique and thermogravimetric analysis. The reactivity ratios of the monomers were computed by Fineman-Ross, Kelen-Tudos, and extended Kelen-Tudos methods at lower conversion. The reactivity ratios obtained r_1 (MMA) 1.69 and r_2 (NVP) 0.03 showed richer content of MMA than NVP in the copolymer having extreme ideal behavior. The distribution of monomer sequence along the copolymer chain was calculated using a statistical method based on reactivity ratios. Ti(III)-DMG redox initiator showed increased addition of NVP to MMA during copolymerization.

In vitro– in vivo evaluation of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) hydrogel implants containing cisplatin

The aim of this study was to prepare hydrogel disc implants containing cisplatin from hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA). To control drug release, the monomers were cross-linked with ethyleneglycol dimethacrylate (EGDMA). Implants were characterized by FTIR, DSC and SEM and evaluated for drug content, swelling, tensile strength, in vitro and in vivo drug release, in vitro and in vivo biodegradation of the polymer and histopathological studies. The in vitro results showed that increasing the concentration of either MMA or EGDMA decreased drug release and prolonged the implant life. Histopathological studies showed that the implants were histocompatible with surrounding tissue. Stability studies on the optimized formulation showed it was stable over 90 days at 25±3 °C. The implants can be used to achieve controlled release of drug and attain effective treatment with reduced side effects.