Modified Poly Methyl Methacrylate Research Articles

Modified polymethyl methacrylate as a sustainable medium for capturing carbon dioxide

This study evaluates the potential of modified polymethyl methacrylate (PMMA) materials, which incorporate organotin moieties pendant on the polymeric chains, as media for carbon dioxide storage. The PMMA containing a triphenyltin moiety has the largest specific surface area (SBET=11.618 m2/g) in comparison to the polymers containing tributyl (5.287 m2/g) and trimethyl (4.881 m2/g) residues. The PMMA with the triphenyltin moiety proved to be the most efficient material in capturing carbon dioxide (34.8 cm3/cm, 6.8 wt%), which is attributed to its relatively high surface area and pore volume and diameter compared to the others.

Enhanced Physio‐Chemical Properties of PMMA/PS Polymer Blends by DC Glow Discharge Plasma Treated K2TI6O13 for Electronic Applications

AbstractCeramic filler modified polymer blends are more in demand due to their excellent compatibility, easy processing and cost‐effectiveness. In the present work, we modified Polymethyl methacrylate (PMMA)/Polystyrene (PS) blends using solution blending with untreated (UT) and DC glow discharge plasma‐treated (air plasma treated‐APT) potassium hexatitanate (K2Ti6O13). Chemical bonding of virgin and modified blends was confirmed by Fourier transform infrared spectrophotometer (FTIR). Decreased structural defects and imperfections of KTO were confirmed by Raman spectroscopy. Modified surface morphology and elemental analysis were detected by scanning electron microscopy (SEM) and energy‐dispersive X‐ray analysis (EDAX). The quantification of particle size distribution has been determined by Zetasizer. Increased degree of crystallinity and decreased average crystallite size after plasma treatment were determined by X‐ray diffraction. Increased dielectric constant from ~22–200 and decreased loss up to 0.7 were analyzed by impedance analyzer. Lee's disc probe was deployed to confirm the optimized thermal conductivity of the modified blend system. By Differential Scanning Calorimetry, glass transition temperature of modified polymer blends was investigated. The change in surface from hydrophobic to hydrophilic by plasma exposure was confirmed by surface goniometer. However, the enhanced dielectric performance of modified PMMA/PS/KTO polymer blends may be suitable for flexible energy storage devices and gadgets.

Chiral resolution of ketoprofen by modified polymethyl methacrylate microspheres

AbstractDue to unique structural characteristics and chiral environment, β‐cyclodextrin (β‐CD) has a strong chiral separation ability. 4‐Chlorophenyl isocyanate (4CPI) also plays an important role in separating chiral drugs. In this paper, a chiral stationary phase: 4‐CPI‐β‐CD stationary phase (4CPI‐β‐CD@PMMA) was designed and prepared. Polymethyl methacrylate (PMMA) microspheres with uniform particle size and good monodispersity were prepared by modified seed polymerization and seed expansion methods. Using diazo resin as a coupling agent, PMMA microspheres were connected with 4CPI‐β‐CD to prepare a stationary phase with chiral recognition ability. PMMA microspheres and 4CPI‐β‐CD were also characterized. Compared with the traditional silica gel column, PMMA microspheres have higher preparation efficiency, better monodispersity, and better mechanical properties as chromatographic fillers. Finally, the chiral separation of ketoprofen was carried out by reversed‐phase high‐performance liquid chromatography, and the separation conditions were optimized. This paper is a good idea for the preparation of the chiral stationary phase.

Evaluation and Assessment of the Colour Stability of Modified Polymethyl Methacrylate Denture Base Materials and Polyether Ether Ketone in a Cast Partial Denture Framework: An In-Vitro Study.

Background One of the frequent aesthetic issues patients confront is the loss of colour and lifeless appearance of the denturesof the base materials of their dentures after regular use. This leads to a lack of motivation to use the denture regularly. Due to the drawbacks of conventional PMMA, polyether ether ketone (PEEK) and newer polymethyl methacrylate (PMMA)-based materialshave now started being used in cast partial denture frameworks dueto their superior physical and biological properties. The lack of long-lasting colourisone of the main reasons for the repeat of dental prostheses. Hence, the need for the study is to help clinicians decide which would be the most suitable denture base materialto be used based on colour stability. Aim To assess and compare the colour stability of PEEK, polyan, and biodentaplast denture base materials (DBMs) upon staining withdistilled water, tea, coffee, and turmeric solutions after one day, seven days, and 30 days. Methods A total of 20 cuboidal specimens were constructed and immersed in distilled water, tea, coffee, and turmeric (five specimens of each material in each solution, a total of 60 specimens): Group 1: PEEK, Group 2: polyan, Group 3: biodentaplast. All specimens were subjected to colour measurements before exposure to beverage solutions, after 24 hours, on the seventh day and 30th day with a colour reflectance spectrophotometer with computer software. A one-way ANOVA test followed by post hoc Tukey's honestly significant difference (HSD) was performed for comparison of colour stability between the DBMs, revealing a significant difference between PEEK and polyan and PEEK and biodentaplast. Polyan showed the highest delta E values, followed by biodentaplast and PEEK.A two-way ANOVA test, followed by Tukey's HSD post hoc, was done to compare the staining ability of various staining solutions. Turmeric had the highest delta E values, followed by coffee, tea, and distilled water. Data were assessed using Statistical Product and Service Solutions (SPSS, version 23) (IBM SPSS Statistics for Windows, Armonk, NY) software. Results The highest mean delta E value at T1 was seen in biodentaplast immersed in turmeric (12.3900+/-0.442), and the least value at T1 was obtained for PEEK immersed in distilled water (0.4460+/-0.036).The highest mean delta E value at T2was seen in polyan immersed in turmeric (13.0160+/-0.28962), and the least value at T2was obtained for PEEK immersed in distilled water (0.5860+/-0.051). At T3, the highest mean delta E value was seen in polyan immersed in turmeric (16.8600+/-0.49845), and the least value at T3 was obtained for PEEK immersed in distilled water (0.700+/-0.037). Conclusion PEEK had the highest colour stability when compared with polyan and biodentaplast.

A19-saponin–modified polymethyl methacrylate base denture composites: antimicrobial, mechanical and water absorption potentials

Abstract The increased growth of Candida albicans (C. albicans) with allergy reaction of MMA remains an issue of concern among denture wearers. C. albicans growth inhibition, mechanical and water absorption potentials of extracted A19-saponin–commingled PMMA denture base composites were investigated. Soxhlet extraction technique for defatting of Dialium guineense (D. guineense) stem powder was used with ethanol to extract A19-saponin. Fungicidal inhibition concentration of A19-saponin extract of D. guineense was determined. PMMA denture base was prepared with incorporation of A19-saponin at different concentrations of obtained 23.2 % yield. The mechanical and water absorption properties were determined. The minimum and maximum fungicidal inhibition concentrations and susceptibility of 25 and 100 % for extracted A19-saponin were obtained, respectively. PMMA, MMA and extracted A19-saponin of ratio of 30 g: 5 ml: 5 ml denture was optimally fabricated. A19-saponin increased the impact strength and hardness by 352.94 and 11.54 % with reduced water absorption by 82.85 %. Thus, A19-saponin as an additive improved quality of denture.

Finite element analysis of biomechanical effects of mineralized collagen modified bone cement on adjacent vertebral body after vertebroplasty.

Objective: To investigate whether mineralized collagen modified polymethyl methacrylate (MC-PMMA) bone cement impacts the implanted vertebral body and adjacent segments and the feasibility of biomechanical properties compared with common bone cement in the treatment of osteoporotic vertebral compression fractures (OVCF). Methods: A healthy volunteer was selected to perform a three-dimensional reconstruction of the T11-L1 vertebral body to establish the corresponding finite element model of the spine, and the changes in the stress distribution of different types of cement were biomechanically analyzed in groups by applying quantitative loads. Results: The stress distribution of the T11-L1 vertebral body was similar between the two bone types of cement under various stress conditions. Conclusion: Mineralized collagen modified bone cement had the advantages of promoting bone regeneration, good biocompatibility, good transformability, and coupling, and had support strength not inferior to common PMMA bone cement, indicating it has good development prospects and potential.

Mechanical Properties and Antifungal Activity of Ganoderma Lucidum Modified Polymethylmethacrylate: An In-vitro Study.

Mechanical Properties and Antifungal Activity of Ganoderma Lucidum Modified Polymethylmethacrylate: An In-vitro Study.

A Preliminary Review of Modified Polymethyl Methacrylate and Calcium-Based Bone Cement for Improving Properties in Osteoporotic Vertebral Compression Fractures

The incidence of osteoporotic vertebral compression fractures (OVCFs) increases gradually with age, resulting in different degrees of pain for patients, even possible neurological damage and deformity, which can seriously affect their quality of life. Vertebral augmentation plays an important role in the surgical treatment of OVCFs. As the most widely used bone cement material, polymethyl methacrylate (PMMA) offers inherent advantages, such as injectability, ease of handling, and cost-effectiveness. However, with its application in the clinic, some disadvantages have been found, including cytotoxicity, high polymerization temperature, high elastic modulus, and high compressive strength. To improve the mechanical properties and the biological performance of conventional PMMA bone cement, several studies have modified it by adding bioceramics, bioglass, polymer materials, nanomaterials, and other materials, which have exhibited some advantages. In addition, other alternative materials, such as calcium phosphate, calcium sulfate, and calcium silicate cements—including their modifications—have also been explored. In this review, we examined the existing research on the side-effects of conventional PMMA bone cement, modified PMMA bone cement, and other alternative materials designed to improve properties in OVCFs. An overview of various modified bone cements can help further scientific research and clinical applications.

High Tg and excellent ultraviolet-shielding efficiency modified PMMA derived from protocatechuic acid

The precise synthesis of acrylate derived from protocatechuic acid was reported for the first time via a simple two-step reaction route. Copolymerizing the monomer with methyl methacrylate in the presence of radical initiator gave the copolymers. The copolymer exhibited high glass transition temperature (Tg) and thermostability, excellent ultraviolet-shielding efficiency and good dimensional stability. Moreover, the modified polymethyl methacrylate (PMMA) also showed good mechanical properties while the transparency lightly decreased in visible light. The best results were obtained when the weight ratio of methyl methacrylate and protocatechuic acid -based acrylate was 1:1. In that case, the cured polymer showed Tg of 159.6 °C and a coefficient of thermal expansion (CTE) of 69.54 ppm/°C. The shielding rate of copolymer reached 99.38% in ultraviolet light (320–400 nm) and 82.56% in short-wave blue light (400–450 nm). These indicated that it may be applied to lenses, and this contribution would provide a new way for the conversion of bio-based glucose to the high-performance polymers.

English

BACKGROUND Dimensional change and porosity in the polymethylmethacrylate based prosthesis affects its clinical performance. Hence, the present study aimed to evaluate the porosity and water sorption present in the modified polymethyl methacrylate polymer composite. METHODS Control group without fibre reinforcement and test groups with fibre reinforcement were prepared for the study. Three different fibres such as boron free-E glass fibre, untreated and plasma-treated polypropylene fibres in varying weight percentage and aspect ratio were considered for reinforcement. The porosity of the fractured surface was observed through a scanning electron microscope (scanning electron microscope) and sorption measured based on international standards organization (ISO) 1567:1999. RESULTS Control group exhibited porous structures, whereas all fibre-reinforced groups did not exhibit porous structure at the fracture surface. There was a significant difference in the sorption rate between control and test group (p < 0.001). Among fibrereinforced test groups, boron free E glass fibre reinforced polymethylmethacrylate exhibited maximum sorption followed by polypropylene fibre reinforced polymer test groups (p < 0.001). However, all samples showed sorption rate within the ISO specification. CONCLUSIONS Fiber reinforcement is an effective method to reduce porosity and water sorption in polymethylmethacrylate based polymer composite regardless of the fibre type. KEY WORDS Polymer Composite, Porosity, Water Sorption, Fiber Reinforcement, Polymethylmethacrylate

Insecticidal activity of some synthesized 1,3,4-oxadiazole derivatives grafted on chitosan and polymethylmethacrylate against the cotton leafworm Spodoptera littoralis

To combat insect pests and vectors that are responsible for high losses in food and lives, insecticide discovery is of top priority. This study aimed to synthesize, characterize and investigate the insecticidal activity of 1,3,4-oxadiazole derivatives grafted on chitosan (CS) and modified polymethyl methacrylate (PMMA). 5-(pyridin-3-yl)-1,3,4-oxadiazole-2-thiol and 5-(pyridin-4-yl)-1,3,4-oxadiazole-2-thiol were respectively reacted with ethylchloroacetate and methyl-2-choloroacetoacetate. The resulted esters were grafted with CS and modified-PMMA. The products were characterized using FT-IR, 1H NMR, TGA, and XRD techniques. Four CS grafted ones were able to show good insecticidal activity against the cotton leafworm Spodoptera littoralis. Furthermore, the safety of these compounds was tested using MTT assay on a human cell line (WI-38). The results indicated that compounds 2a, 2b, 6a, and 6d are considered insecticide candidates to S. littoralis fourth-instar larvae. Cytotoxicity of 2b and 6d indicated that they are the least toxic to humans. It is concluded that both compounds may represent promising insecticide candidates.

The clinical results of treating Kummell's disease with mineralized collagen modified polymethyl methacrylate.

To investigate the clinical results of treating Kummell's Disease by using mineralized collagen modified polymethyl methacrylate bone cement, 23 cases (23 vertebras) who sustained Kummell's Disease treated with mineralized collagen modified polymethyl methacrylate bone cement from July 2017 to February 2019 were reviewed retrospectively. The visual analogue scale, vertebral body height, Cobb angle, CT values pre-operation and post-operation as well as incidence of complications were observed. All the patients were successfully followed up with an average period of 11.3 months (ranging from 6 to 12 months). The patients could ambulate on the second day after the operation. The visual analogue scale scores significantly decreased from two days after the operation to the last follow-up compared with that before the operation (p < 0.05); the average vertebral height and local Cobb angle had significant recovery (p < 0.05); the CT value of the treated vertebra significantly increased compared with that before the operation (p < 0.05). Bone cement leakage occurred in one case, anterior edge leakage occurred in one case, and no clinical symptoms caused by bone cement leakage occurred. No re-fracture of the treated vertebral body or adjacent vertebral bodies were observed in the follow-ups. With good osteogenic activity and degradable absorption characteristics, mineralized collagen was compounded with the existing polymethyl methacrylate bone cement to reduce its strength in the vertebral body and enhance biocompatibility, the incidence of adjacent vertebral fractures and re-fractures within the injured vertebrae is significantly reduced, and good clinical results are obtained, which is worthy of popularization.

Antifungal and Surface Properties of Chitosan-Salts Modified PMMA Denture Base Material.

Chitosan (CS) and its derivatives show antimicrobial properties. This is of interest in preventing and treating denture stomatitis, which can be caused by fungi. Therefore, the aim of this study was the development of a novel antifungal denture base material by modifying polymethyl methacrylate (PMMA) with CS-salt and characterizing its antifungal and surface properties in vitro. For this purpose, the antifungal effect of chitosan-hydrochloride (CS-HCl) or chitosan-glutamate (CS-G) as solutions in different concentrations was determined. To obtain modified PMMA resin specimens, the CS-salts were added to the PMMA before polymerization. The roughness of these specimens was measured by contact profilometry. For the evaluation of the antifungal properties of the CS-salt modified resins, a C. albicans biofilm assay on the specimens was performed. As solutions, both the CS-G and CS-HCl-salt had an antifungal effect and inhibited C. albicans growth in a dose-dependent manner. In contrast, CS-salt modified PMMA resins showed no significant reduced C. albicans biofilm formation. Furthermore, the addition of CS-salts to PMMA significantly increased the surface roughness of the specimens. This study shows that despite the antifungal effect of CS-salts in solution, a modification of PMMA resin with these CS-salts does not improve the antifungal properties of PMMA denture base material.

Mineralized Collagen Modified Polymethyl Methacrylate Bone Cement for Osteoporotic Compression Vertebral Fracture at 1-Year Follow-up.

Retrospective comparative study. This study aimed to compare the clinical effects and imaging features of polymethyl methacrylate (PMMA) bone cement with and without mineralized collagen (MC) in percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCFs). PKP with PMMA is widely performed for OVCF. However, numerous complications have also been reported about the PMMA bone cement. Moreover, PMMA bone cement with and without MC have not been compared with respect to their postoperative efficacy and long-term follow-up. From July 2016 to July 2017, 105 OVCF patients were randomly divided into two groups based on their PKP treatment: MC-PMMA group and PMMA group. Clinical operation, cement leakage, Oswestry Disability Index, visual analog scale, height of the fractured vertebrae, Cobb angle, refracture of the adjacent vertebra, recompression, and computed tomography values of the injured vertebra were compared between the two groups postoperatively and after 1-year follow-up. Clinical operation showed no differences between the two groups. Visual analog scale scores, Oswestry Disability Index scores, and Cobb angles showed statistically significant differences between the two groups after 1-year follow-up. The height of the vertebral body showed significant difference at 3 days postoperatively and preoperatively in each group and significant difference after 1 year between the two groups. The rate of refracture and leakage of the MC-PMMA group was lower than that of the PMMA group. The computed tomography value of the MC-PMMA group was obviously higher than that of the PMMA group after 1-year follow-up. MC-modified PMMA did not change the beneficial properties of PMMA. This new bone cement has better biocompatibility, can form a stable structure in the vertebral body, and improve the prognosis of patients by reducing pain and reoperation. 3.

Effect of phosphate ester addition on transverse strength and hardness of heat cured acrylic denture base material

Background: acrylic resin denture base consider a common denture base material for its acceptable cost, aesthetic and easy processing but still has disadvantages including easy of fracture and low impact strength. Material and method: The experimental group was prepared by addition of 15% phosphoric acid 2-hydroxyethyl methacrylate ester (PA2HEME) with polymethyl methacrylate monomer; the experimental groups was compared with the control one. The specimens were prepared according to ADA specification No. 12 with dimension 65 mm x 10 mm x2.5 mm (length x width x thickness respectively). The prepared specimens were tested by three-point flexural strength utilizing Instron Universal Testing Machine (WDW, Layree Technology Co.), Shore D hardness tester used to measure hardness test. Statistical analysis used student T- test, mean and standard deviation. Results: The result of PA2HEME group showed high significant reduction comparing to the control group for both transverse strength and hardness test. Conclusion: Mixing 15% of PA2HEME with 85% methyl methacrylate (MMA) can reduce the mechanical properties of new modified polymethyl methacrylate (PMMA) acrylic resin.

Preparation and Characterization of Glauber's Salt Microcapsules for Thermal Energy Storage

AbstractMicrocapsules with modified polymethyl methacrylate (PMMA) as coating polymer and sodium sulfate decahydrate (Na2SO4 · 10H2O) as core materials were prepared using the emulsion polymerization and solvent evaporation methods. Chemical composition and microscopic structure of the synthesized PMMA-AA/Na2SO4 · 10 H2O phase change materials (PCMs) microcapsules were confirmed by Fourier-transform infrared spectroscopy, polarizing optical microscopy (POM), scanning electron microscopy (SEM). The thermal properties were analyzed by differential scanning calorimetry (DSC) in detail. The results show that the microcapsules are uniform and approximately spherical with an average diameter of about 3.5 μm. The melting point of the microcapsule is 31.5°C and the fusion heat is 182.8 J/g. This demonstrated that the prepared PMMA-AA/Na2SO4 · 10H2O microcapsules could be promising candidates for the design of novel energy-saving materials with good thermal energy storage application.

Enhanced energy transfer between Co-dopants Pyronin-Y and Thionine incorporated into modified polymethyl methacrylate with addition of ZnO nanoparticles

Using a prism dye cell arrangement, the study investigated spectral energy transfer between co-dopants Pyronin-Y and Thionine incorporated into ethanol-modified polymethyl methacrylate. The spectral parameters of the absorption and fluorescence spectra of the donor and acceptor dyes in the so designed solid-state dye laser were calculated theoretically. Fluorescence lasing properties and slope efficiency of the solid-state dye laser were investigated both with and without addition of ZnO nanoparticles. The dye pair generally improved lasing efficiency and tunability in the range from 582 to 689nm.

Wear resistance of a modified polymethyl methacrylate artificial tooth compared to five commercially available artificial tooth materials

Statement of problemWear resistance is a limitation of artificial denture teeth. Improving the wear resistance of conventional artificial denture teeth is of value to prosthodontic patients. PurposeThe purpose of this in vitro study was to evaluate the wear resistance and hardness of modified polymethyl methacrylate artificial denture teeth compared to 5 commercially available artificial tooth materials. Material and methodsThis study evaluated 180 artificial denture teeth (6 groups) that included 3 groups of conventional artificial teeth (MajorDent, Cosmo HXL, and Gnathostar), 2 groups of composite resin artificial teeth (Endura and SR Orthosit PE), and 1 group of modified surface artificial teeth. The flattened buccal surface of each tooth (n=15) was prepared for investigation with the Vickers hardness test and the elucidate wear test (n=15) by using a brushing machine. Each group was loaded for 18 000 cycles, at 2 N, and 150 rpm. The wear value was identified with a profilometer. The data were statistically analyzed by using 1-way ANOVA and post hoc Turkey honestly significant difference tests (α=.001). The tribologies were observed under a scanning electron microscope, and the cytotoxicities were evaluated by MTT assay. ResultsThe Vickers hardnesses ranged from 28.48 to 39.36. The wear depths and worn surface area values ranged from 1.12 to 10.79 μm and from 6.74 to 161.95 μm2. The data revealed that the modified artificial denture teeth were significantly harder and exhibited significantly higher wear resistance than did the conventional artificial teeth (P<.001). The scanning electron microscopic images revealed cross sections of the conventional artificial denture teeth with intensively worn surface areas after brushing. The cytotoxicity test revealed 97.85% cell viability, which indicates the nontoxicity of the modified surface of this material. ConclusionsWithin the limitations of this study, the polymethyl methacrylate modified surface artificial denture teeth was not significantly different from that of the composite resin artificial denture teeth, with the exceptions that the surface was harder and more wear resistant.

Chemically Modified Polymethyl Methacrylate in a Magnesium-Polymer Cell

As a result of the electrophilic protonation of a carboxyl group of dielectric polymethylmethacrylate (PMMA) with trifluoromethanesulfonic acid (CF3SO3H), a modified conducting polymer material was produced in the shape of a thin elastic lamina and a dense conductive gel, whose density was 1.26 g/cm3. These polymers conduct electricity, do not dissolve in either cold or warm water and are also resistant to weather conditions. Their conductivity in room temperature is 7.5·10-3 Scm-1 and it greatly increases above 154 K. Activation energy Ea decreases with increasing temperature in the range 154 K – 300 K from 1.47 eV to 0.69 eV. The magnesium-polymer (Mg-Poly) cell is constructed with magnesium as the anode and conductive PMMA as the cathode and both electrodes are electrically connected with a polymer gel electrolyte. The rated voltage of this cell is 2.4 V.

Chemically Modified Polymethyl Methacrylate in a Magnesium-Polymer Cell

As a result of the electrophilic protonation of a carboxyl group of dielectric polymethylmethacrylate (PMMA) with trifluoromethanesulfonic acid (CF3SO3H), a modified conducting polymer material was produced in the shape of a thin elastic lamina and a dense conductive gel, whose density was 1.26 g/cm3. These polymers conduct electricity, do not dissolve in either cold or warm water and are also resistant to weather conditions. Their conductivity in room temperature is 7.5·10-3 Scm-1 and it greatly increases above 154 K. Activation energy Ea decreases with increasing temperature in the range 154 K – 300 K from 1.47 eV to 0.69 eV. The magnesium-polymer (Mg-Poly) cell is constructed with magnesium as the anode and conductive PMMA as the cathode and both electrodes are electrically connected with a polymer gel electrolyte. The rated voltage of this cell is 2.4 V.