The Effect of AlI3 Nanoadditive on the Thermal Behavior of PMMA Subjected to Thermoanalytical Py-GC-MS Technique

Thermal degradation of polymethylmethacrylate (PMMA) was studied by using inorganic salt of aluminum triiodide (AlI3). The composites of PMMA were prepared with AlI3 by changing the concentration of the AlI3 additive from 2% to 10% (w/w). The PMMA composites with AlI3 were characterized by TGA, DTG, SEM, FTIR, HBT, and Py-GC-MS techniques. The FTIR peaks of PMMA composite at 1316, 786, and 693 cm−1 justify the chemical association between PMMA and AlI3. TGA study shows that the stability of PMMA is enhanced by the addition of the AlI3 additive. SEM analysis represented that there is a relationship between polymer and additive when they are mixed at the molecular level. The horizontal burning test (HBT) also confirmed that the AlI3 additive produced the flame retarding properties in PMMA polymer. The burning rate of composite with 10% of AlI3 additive decreases five times as much as compared to pure PMMA polymer. Py-GC-MS analysis deduced that PMMA composite produced less toxic and environment-friendly substances (CO2) by the influence of AlI3 additive as compared to neat PMMA.

Thermal and optical properties of PMMA films reinforced with Nb2O5 nanoparticles

The article presents the thermal and physical properties of PMMA composite films with the addition of Nb2O5 nanoparticles. The addition of nanoparticles to PMMA mainly influenced the optical transmission and glass transition temperature of composite films compared to pure PMMA. It is clearly visible in the results of the conducted ellipsometric and differential scanning calorimetry tests. X-ray studies showed that the heat treatment of the samples resulted in the ordering of the polymer structure (flattening of the polymer chains). Examining the surface of the samples with scanning electron microscopy, it can be seen that Nb2O5 nanoparticles formed unusual, branched formations resembling "snowflakes".

Heat Treatment at Different Temperatures and its Effect on the Optical Properties of Pure PMMA and PMMA-Coumarin

The effect of thermal treatment on optical constants of pure PMMA and with addition (15 and 35) ml of coumarin at different temperatures (100, 110 and 120) C0 for 1 hour were investigated. Cast method used to prepares films of pure PMMA and PMMA with (15 and 35) of coumarin. UV/VIS spectrometer technique used to measure the absorption spectra for these films. The optical constant (absorption spectra and absorption coefficient) don’t changes after applied temperatures in pure PMMA film but the optical constant (absorption spectra and absorption coefficient) in PMMA with (15 and 35) ml of coumarin increased with applied temperatures. The optical energy gap of pure PMMA and PMMA with (15 and 35) ml of coumarin slightly decreased after applied temperature up to 1200 C.

Antibacterial Mechanism of N-PMI and the Characteristics of PMMA-co-N-PMI Copolymer

Aiming at the excellent killing effect of N-phenylmaleimide (N-PMI) on microorganisms, this paper used structural simulation analysis, fluorescence analysis, confocal laser scanning microscope and SEM to find that the double bond in N-PMI could interact with the sulfur groups in the membrane protein, changing its conformation, rupturing the plasma membrane of the cell, leaking the contents, and ultimately causing the death of the microorganisms. Therefore, once the double bond participated in the polymerization, N-PMI loosed its antimicrobial function. N-PMI could achieve azeotropic copolymerization with MMA through reactive extrusion polymerization, and didn’t follow the law of reactivity ratio of classic copolymerization. N-PMI with a content of 5% can be evenly inserted into the PMMA chain segment during the copolymerization reaction, thereby increasing the Tg of pure PMMA by up to 15°C, which provided the PMMA-co-PMI copolymer with resistance to boiling water sterilization advantageous conditions. In addition, the copolymer was superior to the commercially available pure PMMA in terms of bending strength and modulus. At the same time, N-PMI with a content of 5% has little effect on the transparency of PMMA after participating in the copolymerization. Moreover, the trace amount of residual N-PMI made the material have excellent antimicrobial function, and the bacteriostatic zone is extremely small, which provided an excellent guarantee for the safety and durability of the material. As a medical biological material, the PMMA-co-PMI copolymer has a good industrialization application prospects.

Plasticizer effect on dielectric properties of poly(methyl methacrylate)/titanium dioxide composites

The effect of plasticizer on dielectric properties of poly(methyl methacrylate) (PMMA)/titanium dioxide (TiO2) composites was investigated. Propylene carbonate (PC) was used as plasticizer in the samples which were prepared with the conventional solvent casting technique. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDX) and Differential scanning calorimetry (DSC) analyses and LCR Meter measurements (performed between 300 K and 400 K), were conducted to examine the properties of the composites. With the addition of plasticizer, the thermal properties have changed and the dielectric constant of the composite has increased significantly. The glass transition temperature of pure PMMA measured 121.7°C and this value did not change significantly with the addition of TiO2, however, 112°C was measured in the sample with the addition 4 ml of PC. While the dielectric constant of pure PMMA was 3.64, the ε′ value increased to 5.66 with the addition of TiO2 and reached 12.6 with the addition of 4 ml PC. These changes have been attributed to increase in amorphous ratio that facilitates polymer dipolar and segmental mobility.

Tensile Strength of PMMA/n-ZrSiO4 Composites Using Dynamic Mechanical Analyzer (DMA)

This study aimed to determine the tensile strength and strain properties of poly(methyl methacrylate) (PMMA)/nano-zircon (n-ZrSiO4) composites with various nano-zircon sizes. Wet milling method for 5 and 15 h without annealing treatment was used to obtain the nano-zircon powders. Results showed that milling for 15 hours can reduce zircon size up to 93 nm. Meanwhile, the composites were synthesized with zircon compositions of 1, 2.5, and 5 wt.%. Dynamic Mechanical Analyzer (DMA) measurement were carried out to characterize the tensile-strain dependence on filler compositions of the PMMA/n-ZrSiO4 composites. The PMMA/n-ZrSiO4 composite with 5 wt.% and 15h milling zircon exhibited the highest tensile strength, ca. 10.02 MPa or 2 times of the pure PMMA. The tensile strength of the composites can be explained from the mean size and size distribution of the filler.

The influence of titanate coupling agent on the performance of barium titanate/PMMA denture base nanocomposites after SBF storage

Poly(methyl methacrylate) (PMMA)/nanobarium titanate (NBT) composite has potential application in denture base materials. The denture base materials should be stable in the wet environment and exhibit good mechanical properties. This study aimed to evaluate the effectiveness of titanate coupling agent (TCA) on NBT behavior after soaking in the simulated body fluid (SBF) and to determine the effect of SBF exposure on fracture toughness of the PMMA nanocomposites. Silanated (Si-NBT), titanated (Ti-NBT), and pure NBT (Un-NBT) at 5% concentration (by mass) were incorporated in the PMMA matrix. NBT was sonicated in MMA prior to mixing with PMMA. SBF absorption, solubility, and leaching were measured, and fracture toughness of the PMMA nanocomposites was evaluated after soaking. The results showed that Titanated samples displayed lower SBF absorption capability and solubility values than the silanated ones. Moreover, the leachability of filler elements (Ba and Ti) was substantially reduced by titanation (54% and 61%, respectively), whereas the Si-NBT/PMMA revealed values of 12.3% and 7% respectively. Significant differences in fracture toughness were observed among the tested samples after 6 weeks of aging in SBF ( p < 0.05). Although no notable changes in the KIC of pure PMMA and Un-NBT/PMMA samples were detected, KIC was improved by 20% after titanation. In addition, the fracture toughness of the titanated samples was higher than that of the silanated ones by 26%. In conclusion, TCA exhibited better stability in moisture than silane. Degradation resistance to moisture obtained with titanated NBT could lead to the promotion of clinical longevity of the composites.

Impact Strength, Flexural Modulus and Wear Rate of PMMA Composites Reinforced by Eggshell Powders

In the present study, the impact strength, flexural modulus, and wear rate of poly methyl methacrylate (PMMA) with eggshell powder (ESP) composites have been investigated. The PMMA used as a matrix material reinforced with ESP at two different states (including untreated eggshell powder (UTESP) and treated eggshell powder (TESP)). Both UTESP and TESP were mixed with PMMA at different weight fractions ranged from (1-5) wt.%. The results revealed that the mechanical properties of the PMMA/ESP composites were enhanced steadily with increasing eggshell contents. The samples with 5 wt.% of UTESP and TESP additions give the maximum values of impact strength, about twice the value of the pure PMMA sample. The calcination process of eggshells powders gives better properties of the PMMA samples compared with the UTESP at the same weight fraction due to improvements in the interface bond between the matrix and particles. The wear characteristics of the PMMA composites decrease by about 57% with increases the weight fraction of TESP up to 5 wt.%. The flexural modulus values are slightly enhanced by increasing of the ESP contents in the PMMA composites.

Effect of Iodine Addition on Improving the Electrical Conductivity and Activation Energy of Electrospun PMMA Thin Films

Conductive polymer films were prepared from poly (methyl methacrylate) PMMA with (0, 0.3, 0.5, 0.7, and 0.9) wt. % of iodine, using electrospinning technique. A decrease was noticed in the polymer solution viscosity with increasing the iodine weight percentage while both surface tension and electrical conductivity of the polymer solutions were increased .The structure and morphology of the prepared films were characterized by scanning electron microscopy SEM, the average fiber diameter measured statistically from the SEM images and was equal to 800 nm for PMMA with 0.7 wt. % iodine thin film, and 400 nm for the pure PMMA thin film. The electrical conductivity was enhanced for the electrospun films with increasing iodine concentration, from (29.5518× 10-9 S/cm) for pure PMMA film to (59.3725× 10-9 S/cm) for PMMA with 0.9 wt. % of iodine additives at room temperature. Activation energy decreased from 0.4483 e.V for pure PMMA to 0.43029 e.V for PMMA with 0.9 wt. % iodine.

Microstructure Characterisation and Identification of the Mechanical and Functional Properties of a New PMMA-ZnO Composite

In this research work, we synthesised poly(methyl methacrylate) (PMMA) enriched with 2 wt.% zinc oxide nanoparticles (ZnO) through conventional heat polymerisation and characterised its microstructure. It was found that the distribution of ZnO nanoparticles was homogeneous through the volume of the PMMA. The mechanical testing of the PMMA-ZnO composite primarily included the determination of the compressive properties on real dentures, while density measurements were performed using a pycnometer. The testing of functional properties involved the identification of the colour of the new PMMA-ZnO composite, where pure PMMA acted as a control. In the second step, the PMMA-ZnO cytotoxicity assays were measured in vitro, which were shown to be similar to the control PMMA. Based on this, it could be concluded that the newly formed PMMA-ZnO composite did not induce direct or indirect cytotoxic effects in L929 cell cultures; therefore, according to ISO/DIN 10993-5:2009, this composite was categorised as non-cytotoxic.