PMMA Research Papers - Academia.edu (original) (raw)

Compared to traditional prosthetic pylon materials (Aluminum, Titanium, or Stainless steel.), composite prosthetic pylon materials are used instead of metals. Vacuum bagging technique was adopted for the preparation of specimens made of Poly methyl methacrylate (PMMA) as matrix with constant Perlon layers and different number of Hybrid (Carbon + Glass) fibers layers as reinforcement materials at (±45º&0º/90º) orientation relative to applied load. Also the finite element method (ANSYS-15) were used by create a model of prosthetic pylon and applied compressive load at heel strike step from gait cycle to known the critical buckling stress. The experimental and numerical results shown that the tensile strength, modulus of elasticity, and critical buckling stress increases with increasing number of Hybrid fibers layers, that equal to (145 MPa, 6.25 GPa, and 670 MPa) respectively, and the percentage of increase in tensile strength, modulus of elasticity, and critical buckling stress for specimen with three Hybrid (Carbon + Glass) layers and Perlon layers in PMMA resin compared with pure PMMA specimen was (302.7% , 300% & 257.22%) respectively, at (0º/90º) fibers orientation relative to tensile force.

- by
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- Composite Materials, PMMA, Prosthetics, Buckling

In this paper, we have investigated the capability of the Scanning Electron Microscope (SEM) JEOL JSM6460LV with Raith-ELPHY Quantum, EBL-system for the fabrication of micro-scale Fresnel rings on silicon Si, substrate for optoelectronics devices application. The design of Fresnel rings was achieved by hierarchical structures in extended Graphic Database System GDSII Editor which is sub-software built in the Raith-ELPHY Quantum software. The Fresnel rings were fabricated by exposing electron beam on PMMA photoresist in the Fresnel zones’ region on Silicon substrate. A Fresnel rings is made up of eleven concentric rings having the maximum diameter of the external rings as 52μm, and the minimum diameter of the internal ring as 5μm was fabricated by this method.

- by Nura Chiromawa
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- Nanotechnology, PMMA, Optoelectronics, SEM

Nanocomposite material which contains inorganic nanolayer clay and organic polymer has attracted considerable attention in recent years. Particularly, intercalation of organic polymer into inorganic layered host lattice has approved to be an effective way to construct inorganic–organic nanosystem. The Raman and FTIR spectrum of kaolinite, a layer silicate of composition A12Si2O5(OH)4, from Aldrich Company (Germany) with a diameter of 5–10 , is reported. Kaolinite treated by dimethylsulfoxide (DMSO) as an aqueous system to expand the interlayer basal spacing.In the OH stretching region, a Raman band of kaolinite is observed at 3624 , and at 3481 after modified. IR kaolinite have four bands for OH stretching, and five bands after modified. Then the organic molecules-modified kaolinite (Kaolinite/DMSO) uses clay precursor to synthesize the PMMA/kaolinite intercalation nanocomposites via solution intercalation. The spectrum of Raman and FTIR shows results which agrees of high degree of precision with experiments and previous studies.

- by GJESR Journal and +1
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- PMMA, Nanocomposite materials, Kaolinite, FTIR spectrum
- by Jiao Fei
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- Mechanical Engineering, PMMA, Micro Milling

In this paper, we have investigated the capability of the Scanning Electron Microscope (SEM) JEOL JSM-6460LV with Raith-ELPHY Quantum, EBL-system for the fabrication of micro-scale Fresnel rings on silicon Si, substrate for optoelectronics devices application. The design of Fresnel rings was achieved by hierarchical structures in extended Graphic Database System GDSII Editor which is sub-software built in the Raith-ELPHY Quantum software. The Fresnel rings were fabricated by exposing electron beam on PMMA photoresist in the Fresnel zones' region on Silicon substrate. A Fresnel rings is made up of eleven concentric rings having the maximum diameter of the external rings as 52µm, and the minimum diameter of the internal ring as 5µm was fabricated by this method.

- by Nura Chiromawa
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- Nanotechnology, PMMA, Optoelectronics, SEM

In the current research, the heat-cured matrix material powder of PMMA was reinforced with Peanut and Walnut Shells (natural powders) which are chemically treated with 5% (w/v) (NaOH) to improve the matrix bonding (PMMA) before being used as a reinforcing powder and adding to exactly similar averages particle sizes ≤ (53μm), with different weight fractions of (4, 8, and 12 wt.%). The results indicated that the Elastic modulus values reached their maximum value at (8 wt.%.) when reinforced with Peanut Shells powders (1.053Gpa), while, the values of tensile strength, elongation percentage at the break, decrease as the weight fraction of Peanut and Walnut Shells powders increase and the lowest values are obtained by reinforcing with Peanut Shells powders to reach their minimum values at (12 wt.%) where the lowest values of them are (29 MPa, 2.758%) respectively. The fracture surface morphology of pure PMMA seemed to be homogenous morphology in (SEM) test, whereas the fracture surface morphology of PMMA composite reinforced by (Peanut and Walnut Shells) powders and shows a smoothness fracture surface morphology this refers to brittle to semi ductile or ductile transformation.

- by Jawad K. Oleiwi
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- PMMA, Dentures, Composite, Dental
- by Erasmo Villagomez
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- PMMA

A modern alternative to the positive-tone PMMA resist is the ZEP 520A (Nippon Zeon) brand co-polymer resist, which offers a higher sensitivity and etch durability for electron beam lithography. However, the molecular mechanisms are not entirely understood, and the relative performance of two resists for various process conditions of nanofabrication is not readily predictable. The authors report a thorough experimental comparison of the performance of PMMA 950k and ZEP 520A resists in MIBK:IPA, ZED, and IPA:water developers. Interestingly, ZEP resist performance was found to depend significantly on the developer. ZED developer increases the sensitivity, whereas IPA:water optimizes line edge roughness and conceivably the resolution at the expense of sensitivity. The authors also describe two alternative numerical models, one assuming an enhancement of the main chain scission in ZEP as a result of electronic excitations in side groups, and another without such enhancement. In the second case, the differences in ZEP and PMMA resists performance are attributed to their different interaction with the developers. Using both approaches, the authors parameterize the respective models of ZEP development by fitting numerical results to the experimental resist morphologies, and analyze the outcomes.

- by Mohammad Ali Mohammad and +2
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- Electrical Engineering, Polymer Engineering, Physics, MEMS

Este trabalho consiste no desenvolvimento de um método para a usinagem a laser de modelos 3D em máquinas galvanométricas pós-objetivas, por meio da gravação de múltiplas camadas bidimensionais. Foi realizado um estudo para estabelecer os parâmetros de processo por meio de ensaios e ajustes no equipamento utilizado. Com o desenvolvimento de um dispositivo para controle do deslocamento vertical da mesa de trabalho, foi possível determinar com exatidão o ponto focal, bem como o passo da máquina (altura da camada). O substrato utilizado no estudo foi o PMMA Poli(metacrilato de metila) com um laser de CO2 de 43 W. Foram ensaiados os parâmetros de largura e profundidade dos rasgos formados pelo laser, bem como o ângulo de incidência. Foi possível determinar a profundidade da camada usinada em função dos parâmetros avaliados, bem como produzir modelos 3D com camadas de até 0,2 mm (com velocidade de 100 m/min e espaçamento entre linhas de 0,04 mm). Análises dimensionais foram realizadas por digitalização tridimensional, as quais mostraram erros médios na ordem de 0,1 mm nas peças produzidas. O resultado evidencia o potencial desta pesquisa ao propiciar a criação de uma nova funcionalidade para máquinas de gravação a laser, por exemplo, para fab labs e laboratórios de criação e design, para confecção de pequenos protótipos.

In the paper the analysis of luminescence emission in the VIS spectra range of fabricated multicomponent glasses doped with rare-earth ions and PMMA doped with dyes were presented. Up-conversion emission in: germanate glass co-doped with 0.5Yb2O3/0.75Eu2O3 mol% under 976 nm excitation has been investigated. Down-conversion mechanism was analyzed in phosphate glasses doped with 0.5 mol% Tb2O3 and PMMA co-doped with fluorescein and rhodamine B. Phosphosilicate glasses doped with Er3+ ions have been also studied in order to fabricate target for manufacturing planar waveguides by RF-sputtering deposition. Fabricated materials can be used for fabrication of optical fibers. In result blue up-conversion emission in double-clad optical fiber with Yb3+/Tm3+- doped core was presented.

- by Marian Marciniak and +4
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- Glass, PMMA, Luminescence, Rare Earth
- by Junwei Su
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- Nanotechnology, PMMA, Focused Ion Beam, AFM

In the present research, efforts are made to develop the properties of PMMA resin that used for upper and lower prosthesis complete denture, by addition four different types of nanoparticles powders, which are fly ash, fly dust, zirconia and aluminum that added with different ratios of volume fractions of (0.01, 0.02 and 0.03) to poly methyl methacrylate (PMMA), cold cured resin (castavaria) is the new fluid resin (pour type) as a matrix. The nano composite and hybrid nano composite for prosthetic dentures specimens, preparation was done by using (Hand Lay-Up) method as six groups which includes: the first three groups consists of PMMA resin reinforced by fly ash , fly dust and ZrO2 nanoparticles respectively, the second three groups consists of three types of hybrid nano composites, which includes ((PMMA:X% fly ash)-(1%Al + 3%ZrO2)), ((PMMA:X% fly dust)-(1% Al + 3%ZrO2)) and ((PMMA:nZrO2)-(1% fly ash+ 3% fly dust)) respectively. As well as, the effect of moisture and UV was taking into consideration in this study. The compression test results shows that the values of compressive strength, compressive elastic modulus, and compressive strength under the effect of accelerated weathering (moisture and UV radiation) increased with the addition of nano powders (fly ash, fly dust, zirconia and aluminum). As well as, the results showed that the maximum values of compressive strength reach to (286.25MPa) for (PMMA + 2%nZrO2) nano composite. In addition, the results showed that the compressive elastic modulus reach to the maximum value (25.4166GPa) in the nano composite material (PMMA + 2%nZrO2). Moreover, the results showed that the compressive strength under the effect of accelerated weathering (moisture and UV radiation) reach to the maximum value to (315MPa) for the nano composite material (PMMA + 3%nZrO2).

- by Jawad K. Oleiwi
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- Weathering, PMMA, Nanocomposite, Dentures

In this paper, PMMA/ZnO nanocomposites have been prepared by a very simple, facile and versatile chemical approach. The prepared PMMA/ZnO nanocomposites possess no color, high transparency, good thermal stability, UV-shielding capability, luminescence and homogeneity. The chemical process involved solution mixing of ZnO nanoparticles dispersed in DMAc with the Polymethylmethacrylate (PMMA) matrix dissolved in the same solvent. The effect of ZnO content on the physical properties of the PMMA matrix is investigated by X-ray diffraction, field emission scanning electron microscopy, thermogravimetric analysis, UV–Vis absorption and photoluminescence spectroscopy. It was found that pure hexagonal ZnO nanoparticles with an average particle size of 4–8 nm were homogeneously dispersed in the PMMA matrix. A significant improvement in thermal properties was observed with the incorporation of 1.0 wt% ZnO nanoparticles. The prepared nanocomposite films are highly transparent and a clear excitonic peak is observed in their absorption spectra. Measurement of room temperature photoluminescence spectra shows intensive near-band edge emission peak at 3.28 eV without any structural defects for a nanocomposite film with a filler content of 1.0 wt%.

- by Majid Khan
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- Polymer Nanocomposites, PMMA, Polymer Nano Composite, ZnO (Zinc Oxide)
- by Vincenzo Tagliaferri
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- PMMA, Depth

Objectives: This study is an attempt to enhance the properties of conventional PMMA denture material by incorporation of a polyfunctional polyol derived from palm oil by copolymerization with methyl methacrylate monomer to overcome the low fatigue resistance property of PMMA. Methods: A series of copolymerizations of palm oil polyol with MMA was performed in solution. The polyol was added from 40-20 , MMA from 20-40 , benzoyl peroxide as initiator was at 0.04 and toluene used as solvent was at 60 of the total weight. The copolymerization was carried out in a 500ml-round-bottom reaction flask, equipped with a magnetic stirrer, for 7.5 hour at 80ÂºC, in a water bath. The yield of each copolymerization obtained was recorded and the conversion was estimated gravimetrically. Later, the polymers acquired were analyzed by FTIR. Results: The copolymerizations have achieved conversions that ranged from 24 to 95, where the higher conversion was obtained when the reactant mixture contain higher amount of MMA. The reaction produced a clear color, light-weighted copolymer that has the potential to be developed as denture material. The evidence of incorporation of the polyol into PMMA was given by the FTIR measurements, by comparing the spectrum of the copolymer to the spectrum of PMMA and polyol. Evaluations of the mechanical properties were currently being carried out. Conclusion: The new copolymers have potential of being developed into new dental materials. The branching structure of the copolymer was expected to improve the impact strength of PMMA. In addition, the palm oil based polyol was made from natural sustainable material. This study was supported by E-Science fund, Grant No.: 03-0103-SF0190 and University of Malaya, Postgraduate Research Vote Grant No. : PS 079C/ 2007C and National Science Fellowship (NSF 2007/2008).

Poly Methyl Methacrylate resin distinguished by its low impact and fatigue strength, there are many researches that will deal with these situations. In the current study the matrix was heat cured material powder of PMMA was reinforced with peanut and walnut Shells to PMMA base material, which commonly utilize in the applications of denture. these natural powders were added in various weights fraction (4%, 8%, and 12%), and with similar average particle size (53μm) and studied Density and water absorption properties. In this study the method used to prepare the specimens is Hand Lay-Up method. The results showed that the values of density are increased when the weight fractions of both reinforcing natural particles increased and the maximum value was obtained with adding peanut shells powder at (12 wt.%.) (1.206 gm/𝑐𝑚3) for the composite specimens, while the values of water absorption Tests was decreased by increasing the weight fractions of both reinforcing powders peanut and walnut Shells in PMMA resin and The lowest values was obtained by adding peanut shells powder at (12 wt.% P) (0.003 % ).

- by Jawad K. Oleiwi
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- Dentistry, Composites, PMMA, Dental

The authors report the nanomachining of sub-20-nm wide doubly clamped silicon carbon nitride resonators using low keV electron beam lithography with polymethyl methacrylate resist and cold development. Methodologies are developed for precisely controlling the resonator widths in the ultranarrow regime of 11–20 nm. Resonators with lengths of 1–20 μm and widths of 16–280 nm are characterized at room temperature in vacuum using piezoelectric actuation and optical interferometry. Clamping and surface losses are identified as the dominant energy loss mechanisms for a range of resonator widths. The resonator clamping points are optimized using an original electron beam lithography simulator. Various alternative clamping point designs are also modeled and fabricated in order to reduce the clamping losses.

- by Mohammad Ali Mohammad
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- Electrical Engineering, Physics, Sensors and Sensing, MEMS
- by nazar ahmed
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- PMMA, Compressive Strength, Thermal Conductivity, Cob

Poly methyl methacrylate (PMMA), are widely used as a prosthodontic denture base, the denture base materials should exhibit good mechanical properties and dimensional stability in moist environment. In the present research, efforts were made to develop the properties of PMMA resin that used for upper and lower prosthesis complete denture, by addition four different types of nanoparticles, which are fly ash, fly dust, zirconia and aluminum that added with different ratios of volume fractions of (1%, 2% and 3%) to poly methyl methacrylate (PMMA), cold cured resin (castavaria) is the new fluid resin (pour type) as a matrix. In this work, the Nano composite and hybrid Nano composite for prosthetic dentures specimens, preparation was done by using (Hand Lay-Up) method as six groups which includes: the first three groups consists of PMMA resin reinforced by fly ash , fly dust and ZrO2 nanoparticles respectively, the second three groups consists of three types of hybrid Nano composites, which includes ((PMMA:X% fly ash)+ (1%Al + 3% ZrO2)), ((PMMA:X% fly dust)+ (1%Al + 3% ZrO2)) and ((PMMA:X%nZrO2)+(1%fly ash+3%fly dust)) respectively. As well as, the effect of water absorption was taking into consideration in this study. The compression test results show that the values of the compressive strength with and without the effect of water absorption increased with the addition of Nano powders (fly ash, fly dust, zirconia, and aluminum). Also, the results showed that the maximum values of compressive strength reach to 286.25MPa for (PMMA: 2%nZrO2) Nano composite. Whereas the maximum values of compressive strength for hybrid Nano composite reach to 270MPa for ((PMMA: 2%fly ash) + (1%Al + 3% ZrO2)) hybrid Nano composite. Moreover, the results showed that the maximum value of compressive strength under the effect of water absorption reach to 335MPa in the Nano composite material (PMMA+2% fly dust), whereas the maximum value of compressive strength under the effect of water absorption for hybrid Nano composite reach to 632MPa for ((PMMA: 2% fly dust) + (1%Al + 3% ZrO2)) hybrid Nano composite.

- by Jawad K. Oleiwi
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- Nanomaterials, Composite Materials, PMMA, Complete Dentures

Optical communication is an internationally accepted communication for long distance communication. As it is a reliable way of communication it can be implement in short distance communication. The term short distance communication is commonly define for in-home connections, automotive, hospitals etc. For short distance communication low cost, low lose high speed and high capacity transmission medium is required. In this work it explains about an optical transmission medium that is a plastic optical fiber instead of a glass fiber as it can meet all the demands of short distance communication requirements. This paper defines about a POF link and its scope in recent years. Some of the prime objectives or demands that need to be addressed are increased capacity, improved data rate, decreased latency, and better quality of service. To meet these demands, drastic improvements need to be made in cabling side. This paper presents the results of a detailed survey and scopes of POF.

This research was conducted to develop a 1×12 optical splitter based on polymer optical fiber (POF) made from polymethyl methacrylate (PMMA) material as a high efficiency optical signal transmission medium. Basically, the optical device has 1 POF input port and 12 POF output ports in a bundled fiber form. There are several system available in the market which are able to split or couple optical signals transmitted into some different channels, which are all afflicted with certain constrains. However, these systems are too expensive for most applications. The goal of this research was to develop an economical splitter for multi-purpose application over PMMA-POF. Red LED with 650 nm wavelength was injected into the splitter with the aim to analyze the power efficiency of the splitter. A coupling efficiency of 80% was demonstrated. The performance of these hand-made splitters can be improved gradually through experience and practice.

- by Hadi Guna
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- PMMA, Wdm, POF, Polymer Optical Fiber

Poly methyl methacrylate (PMMA), widely used as a prosthodontic denture base, the denture base materials should exhibit good mechanical properties and dimensional stability in moist environment. In the present research, efforts are made to develop the properties of PMMA resin that used for upper and lower prosthesis complete denture, by addition four different types of nanoparticles, which are fly ash, fly dust, zirconia and aluminum that added with different ratios of volume fractions of (1%, 2% and 3%) to poly methyl methacrylate (PMMA), cold cured resin (castavaria) is the new fluid resin (pour type) as a matrix. In this work, the Nano composite and hybrid Nano composite for prosthetic dentures specimens, preparation was done by using (Hand Lay-Up) method as six groups which includes: the first three groups consists of PMMA resin reinforced by fly ash , fly dust and ZrO2 nanoparticles respectively, the second three groups consists of three types of hybrid Nano composites, which includes ((PMMA: X% nF.A)+ (1%Al + 3% ZrO2)), ((PMMA: X% nD.A)+ (1%Al + 3% ZrO2)) and ((PMMA-X%nZrO2)+(1%F.A + 3%F.D)) respectively. The hardness and flexural tests results show that the values of the hardness, flexural strength, Maximum shear stress and flexural modules increased and with the addition of Nano powders (fly ash, fly dust, zirconia, and aluminum). And the results showed that the maximum values of hardness reach to (84.166) for ((PMMA: 3%nZrO2) + (1%F.A + 3%F.D)) hybrid Nano composite, whereas the maximum values of hardness for Nano composite reach to (83.333) for (PMMA: 3%nZrO2) Nano composite. Also, the results showed that the maximum values of flexural strength and Maximum shear stress reaches to (101MPa) and (2.4738MPa) respectively for (PMMA: 2%nF.D) Nano composite. Moreover, the results showed that the maximum values of flexural modules reaches to (13.95GPa) for ((PMMA: 3% nF.A) + (1%Al + 3%ZrO2)) hybrid Nano composite, whereas the maximum values of flexural modules for Nano composite reach to (12GPa) for (PMMA-3%nZrO2) Nano composite.

- by Jawad K. Oleiwi
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- Nanomaterials, Composite Materials, PMMA, Dental

The main objective of this research is studying the tensile and buckling of Jute fibers reinforced composite by varying the number of Jute fibers layers and fibers angle (±45° & 0°/90°). Vacuum bagging technique was adopted for the preparation of laminated composite specimens that made from PMMA as matrix and Perlon layers with different number of Jute fibers layers as reinforcement materials. Also the finite element method (ANSYS-15) was used by creating a model of prosthetic pylon and applied compressive load at heel strike step from gait cycle to know the critical buckling stress. The results showed that the best laminated composite specimens have three Jute fibers layers at (0 º /90 º) fibers orientation relative to applied load. Where, the critical buckling stress, tensile strength, and modulus of elasticity were (442MPa, 61MPa, and 3.75GPa) respectively, while, the percentage elongation was (2.1).

- by Jawad K. Oleiwi
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- PMMA, Prosthetics, Buckling, Pylon

Objectives:Biocompatibility is an important desirable property for a dental polymer and it can be achieved by utilizing more materials from natural sources. The flexural strength of an experimental polymer prepared from MMA monomer modified with palm-oil polyol was compared to two commercial resins,namely the Lucitone 199® (Dentsply Trubyte, USA) and Impact (Ivoclar Vivadent, Liechtenstein). Methods: The experimental polymer was prepared by copolymerizing MMA monomer and palm oil polyol. The resulting polymer was cast into a plate form and sectioned using a precision diamond saw (Buhler, Germany) to form 10 specimens of dimension, 65mm x 11mm x 5mm. These specimens were then polished to achieve a nominal dimension of 64mm x 10mm x 3.3mm. Another 10 specimens were prepared using Lucitone 199® and Impact according to the manufacturers' instructions and were polished by the same procedure. Their flexural strengths were determined using a three point bend test on an Instron Universal Testing Machine (Anytown, Australia)according to the procedure of test method ISO 1567. Data obtained was analysed using Oneway ANOVA (SPSS 12.0) at 95% confidence interval. Results: The mean flexural strength of Lucitone 199® was 127.39MPa (±16.54), Impact was 177.57MPa (±11.44) and experimental polymer was 51.62MPa (±4.21). Although the experimental polymer has exhibited higher flexural strength than PMMA homopolymer, it has lower flexural strength when compared to Lucitone 199® and Impact denture base resins, both of which were filler-reinforced materials. Conclusions:In this preliminary study, the experimental polymer contained a significant proportion of non-petroleum based materials derived from palm oil. Its lower flexural strength is expected to be enhanced and improved through the incorporation of reinforcing fillers or fibers in future work.

- by Noor Hayaty Abu Kasim
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- PMMA, Flexural Strength, Modified, Palm-oil

In this work, we report the fabrication of sub-10 nm wide, doubly-clamped silicon carbon nitride (SiCN) resonators of up to 5 μm lengths. An existing resonator fabrication process has undergone a major improvement through the use of a single hydrogen silsesquioxane (HSQ) masking layer for SiCN patterned using electron beam lithography. Novel development strategies, comprising hot development and HF-trimming development, were also used. The crucial role of post-exposure resist processing in improving the resonator resolution and uniformity was demonstrated. Application of the optimized lithographic process has allowed us to claim the narrowest suspended bridge structures of several microns in length achieved to date.

Various energy harvesting techniques e.g. solar, thermal, wind, etc. are the auxiliary solutions to the depleted battery of Wireless Sensor Network (WSN) Nodes. Hybrid Energy Harvesting (HEH) is the technique to harvest energy from more than one renewable/non-renewable energy sources. In this paper, a thermal and solar energy source based hybrid energy harvesting system has been deeply investigated and implemented to test the feasibility of providing perpetual life time to the sensor node. A mechanical and electrical schematic has been proposed for the HEH system. This is noticed that at day time the energy from the solar light is dominating while at night time thermoelectric energy harvester can provide energy. In the results from thermal modeling, it is found that for a load of 5Ω, maximum power is generated and an increase in ΔT increases the generated energy exponentially and the results drawn from the solar modeling show that increasing the solar irradiance (G) increases the output power. The capacitor gets fully charged in 15minutes (approx.) and the battery gets fully charged in 3hours (approx.).

- by IAEME Publication
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- PMMA, Supercapacitors, Hybrid Energy Harvesting, Iaeme Ijaret

— A modified express method of contact angle measurement based on determining the diameter of a drop with a known volume has been elaborated. The method offers a number of advantages: it can be used in an express manner for in situ dynamic investigation and makes it possible to observe inhomogeneity and anisotropy of hydrophilicity. The method is convenient in comparative measurements and does not require any special equipment. Using the proposed method, the possibility of hydrophilic control of some materials (silicate glass, TiO 2 (anataze) and polymetilmetacrylate (PMMA)) by UV (ultra violet) and chloroform vapor treatment has been studied. In particular, hydrophilicity of PMMA after UV irradiation was observed, and it is shown that changes in hydrophilicity are connected with the surface oxidation of PMMA. The observed phenomenon of hydrophilicity control can be used in various technologies, such as liquid coating, printing, spray quenching, nanolithography, pharmacology and others.

- by Engineering Journal Publication of Research work
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- Engineering, Physics, Research, PMMA
- by Saiful Hadi
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- PMMA, Data Communication, POF, Polymer Optical Fiber
- by muhammad zulfikar
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- Materials Science, PMMA, Teos, Sol-Gel

Fracture in the adjacent levels is one of the consequences to the use of commercial poly methylmethacrylate (PMMA) bone cement. Modified PMMA with a reduced Young’s modulus was found to be safer for cancellous bone augmentation procedures. The aim of this research was to study the effect of adding hydroxyapatite (HA) nano-particles and acetone on different properties of PMMA cement. A commercial PMMA cement was used as a model for bone cement. Three groups of modified PMMA/nano-HA were investigated by adding 2, 4 and 6 wt. % of HA. Acetone as a porogen mixed with distilled water in different amounts (A/W: 1:1, 2:1.5 and 2:1g) was used to produce porous PMMA cement. The residual monomer, polymerization and mechanical properties under tension and compression tests were investigated. Young’s modulus detected from compression test decreased from 826.5±10 to 728±66 MPa by adding 6wt.% HA. Adding acetone to PMMA with 2:1.5g (A/W) has decreased the compressive Young’s modulus to 753±38 MPa. High Performance Liquid Chromatography (HPLC) measurements were carried out with intervals of 2 hours, 6 hours and 24 hours to evaluate the residual monomer for all groups. The amount of residual monomer has decreased after 24 hours of curing by adding acetone and nano-HA. Modifying PMMA by HA and acetone have inconsistent effect on the polymerization temperature. It was concluded that HA and acetone can be used to reduce the stiffness and residual monomer with enhanced biocompatibility of the commercial PMMA bone cement.

- by IEREK press
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- PMMA, Bone Cement, Acetone, Nano-hydroxyapatite

Poly(methyl methacrylate) (PMMA) and sodium montmorillonite (Na-MMT) were melt-blended with 1-dodecyl-3-methylimidazolium hexafluorophosphate (C12mimPF6) to prepare nanocomposites containing well-dispersed MMT layers in nanoscale and freely existed excess C12mimPF6. A synergistic effect of MMT and C12mimPF6 on the foaming behavior of nanocomposites was revealed in this study. At the mild conditions of 17 MPa and 35 °C, neat PMMA and PMMA/C12mimPF6 and PMMA/Na-MMT samples were not foamed, while cells were induced in nanocomposites containing a certain amount of free C12mimPF6. At 25 MPa/90 °C, foamed nanocomposites exhibited higher nucleation efficiency and cell density, and smaller cell sizes with narrower size distribution than that of neat PMMA and those binary samples. The results indicated that the MMT nanoparticles produced heterogeneous nucleation, and increased the modulus of polymer matrix to depress cell coalescence. The presence of free C12mimPF6 decreased the energy barrier for cell nucleation and facilitated the dispersion of MMT nanoparticles via in situ organic modification.
Industrial & Engineering Chemistry Research 08/2013; 52(34):11988–11995.

- by Jian Yu
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- Ionic Liquids, Polymer Nanocomposites, PMMA, Microcellular foams

Exposure of polymethylmethacrylate (PMMA) during electron beam lithography (EBL) produces small polymer fragments that dissolve rapidly during the development process. The resist dissolution behavior varies greatly depending on the nature of the developer (solvent) and therefore influences the selection of the EBL parameters, such as dose (sensitivity). A molecular scale examination of the development process is necessary to elucidate the resist–developer interaction mechanisms. In this work, the authors investigate the interaction of short PMMA chains (containing up to 10 MMA units) with common developer components methyl isobutyl ketone (MIBK) and isopropyl alcohol (IPA). For this purpose, the authors conduct molecular dynamics simulations using the Accelrys Materials Studio package. The simulation results were used to characterize the mixtures in the spirit of the Flory–Huggins theory of polymers and also to extract the diffusivities. The authors found that the behavior of PMMA fragments differed considerably in MIBK as compared with IPA. PMMA fragments containing more than three monomers exhibit stronger attractive interaction with MIBK. For all fragment sizes simulated, the diffusivity of PMMA fragments is 60–160% higher in MIBK as well. Similarly, the authors observed differences in the gyration radii. The authors conclude that the kinetic factor seems to be more significant as compared to affinity factor when accounting for differences in exposure sensitivities due to developer selection.

- by Mohammad Ali Mohammad
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- Polymer Engineering, Physics, Statistical Mechanics, Thermodynamics

This study presents second generation low-cost fused tapered (LFT) 1 × 3 splitter (G2) as novel, low-cost and low-losssplitting device made from PMMA-based polymer optical fiber (POF). G2 (short taper, 0.5 - 2.0 cm) was fabricated byreformulated handwork fusion method using candle and metal tube. A new process, twisting-effect removal, is addeed to refineripple surface in fused input fiber. LED fiber source (wavelength 650) was injected into input fiber while optical power in outputfibers was measured by optical power meter. Insertion loss (7 dB) and excess loss (0.53 dB) for G2 are extremely low. G2 arehomogenous splitters since their splitting ratio are very close to 33:33:33% with ± 5% of tolerance.

- by Hadi Guna
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- PMMA, Wdm, POF, Polymer Optical Fiber
- by stefano secchi
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- Engineering, Mechanical Engineering, Civil Engineering, Applied Mathematics
- by luciano simoni
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- Mechanical Engineering, Civil Engineering, Applied Mathematics, Materials Science
- by Abood Bahajaj and +1
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- Materials Science, Chemistry, Organic Chemistry, Photochemistry

The demand for thermoplastic composites is continuously increasing because these materials offer many advantages over their thermoset counterparts, such as high toughness, long storage time, easy repairing and recycling, and ability to be thermoformed and heat-welded. However, the manufacturing of thermoplastic composite parts using liquid composite moulding techniques (e.g. resin transfer moulding, vacuum assisted resin transfer moulding …) is often tricky in the case of melt processing where high temperature and pressure should be chosen to impregnate the fibre reinforcement because of the high melt viscosity of thermoplastics. These issues may be overcome by means of reactive processing where a fibrous preform is first impregnated by a low viscosity mono- or oligomeric precursor and the polymerization of the thermoplastic matrix then occurs in-situ.
This article draws a state of the art on the manufacturing characteristics of continuous fibre reinforced acrylic-based reactive thermoplastics (e.g. polymethymethacrylate (PMMA) such as Elium), which are becoming more and more popular compared to other fast curing thermosets and thermoplastics for in-situ polymerization. Techniques for the in-situ polymerization of methymethacrylate monomers, characterization and modelling of the rheological properties and polymerization kinetics, and some manufacturing related issues such as polymerization shrinkage are reviewed. Particular features of the use of reactive PMMA in different manufacturing techniques of continuous fibre reinforced composites and potential industrial applications are also introduced. Finally, some perspectives for the academic research and industrial development are proposed.

- by Patricia Krawczak
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- Composites, Advanced Manufacturing, Composite Materials, PMMA

As environmental problems increase, there is an urgent demand for new eco-friendly materials. Natural rubber latex (NRL) is a natural material extracted from rubber trees. But its dyeing process with chemical dyes might result in contamination and environmental degradation. Here, NRL is composited with a photonic crystal (PhC) structure by spin coating for the first time. The polymethyl methacrylate (PMMA) photonic nanostructure has been embedded into NRL to give it colors and provide it with optical functionalities. Colors of the composite could be designed and controlled by the sizes of the nanocolloids from 180 nm to 295 nm. The colors have strong stability under external stretching. The 3D natural rubber latex photonic crystal (NRLPC) is used as a responsive material to detect volatile organic compounds (VOCs) including formaldehyde, acetone, toluene, xylene and styrene. With its visual color appearance, biocompatibility and flexibility, NRLPC has promising potential in various sensing applications.

- by Yu Shen
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- Photonic Crystals, Photonics, Nanotechnology, Rubbers (Materials)

Spiropyran-functionalized poly(methyl methacrylate) (PMMA) Forcespinning® fibers were fabricated using a fiber making machine of our own design, employing 1 0 ,3 0 ,3 0-trimethyl-6-nitrospiro[1(2H)-benzopyran-2,2 0-indoline] (6-nitro BIPS) as the spiropyran. The effects of the polymer solution concentration (and hence the viscosity), the spinneret rotational rate, and the internal needle diameter on the formation and morphology of the fibers were examined, using scanning electron microscopy. A rotational speed of 3000 rpm and an internal nozzle diameter of 0.35 mm (23 G) in conjunction with a polymer concentration of 15 wt% produced 6-nitro BIPS/PMMA Forcespinning fibers having a smooth morphology with no beads. The photochromic properties of the resultant fibers were characterized by reflectance spectroscopy using the Kubelka–Munk function, fluorescence excitation emission matrix (EEM) analysis, and Raman spectroscopy. The thermal decoloration dynamics of the 6-nitro BIPS in the PMMA fibers were in good agreement with the properties observed in films. These results suggest that 6-nitro BIPS and other spiropyran dyes have significant potential as probes to assess the structures of micro/nanofibers.

- by Đoàn Ngọc Hoan and +1
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- Spiropyran, PMMA, Centrifugal Spinning, forcespinning

Luminescent solar concentrators (LSCÃ¢â‚¬â„¢s) are evolving cost-effective organic methods for trapping solar energy using the fluorescence property of organic dyes. The study aims in finding a waveguide design for LSC, in different waveguide materials, PC and PMMA in varying dimensions filled with solution of anthracene in heptane with minimum losses. By comparing the output responses, the LSC with the waveguide design of 6 cm x 3cm x 5cm made of the PMMA (3mm thick) is observed to trap more incident radiation than the unaided solar cells. The maximum output current is measured to be 6.10 mA for a source of 40W power which is convincingly higher than 3.21 mA obtained from the unaided solar cell measured with the same source.

- by Muzaffer Mohammed
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- Biochemistry, Chemistry, PMMA, Silver Nanoparticles

Previous attempts have been devoted to mimic biological vision intelligence at the architectural system level. In this paper, a novel imitation of biological visual system intelligence is suggested, at the device level with the introduction of novel photodiode morphology. The proposed bio-inspired nanorod photodiode puts the depletion region length on the path of the incident photon instead of on its width, as the case is with the planar photodiodes. The depletion region has a revolving volume to increase the photodiode responsivity, and thus its photosensitivity. In addition, it can virtually boost the pixel fill factor (FF) above the 100% classical limit due to decoupling of its vertical sensing area from its limited planar circuitry area. Furthermore, the suggested nanorod photodiode photosensitivity is analytically proven to be higher than that of the planar photodiode. We also show semi-empirically that the responsivity of the suggested device varies linearly with its height; this important feature has been confirmed using Sentaurus simulation. The proposed nano-photorod is believed to meet the increasingly stringent High-Resolution-Low-Light (HRLL) detection requirements of the camera-phone and biomedical imaging markets.

- by Mohammad Ali Mohammad and +1
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- Electrical Engineering, Computer Vision, Nanofabrication, Electron Beam Lithography

The authors report a systematic experimental study of dense nanostructures in polymethylmethacrylate (PMMA) created by low-energy electron beam lithography (EBL) with varying duration and temperature of the resist dissolution. They observe that decreasing the development temperature not only yields the widest favorable exposure dose regimes but also requires highest exposure doses to fabricate dense nanopatterns. They interpret the observed interdependence of the exposure doses and the development temperatures in terms of a simple kinetic model describing the diffusion mobility of fragments in exposed PMMA during dissolution and discuss the corresponding molecular mechanisms that determine the resolution and sensitivity of EBL nanofabrication.

- by Mohammad Ali Mohammad and +1
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- Electrical Engineering, Microelectronics And Semiconductor Engineering, Polymer Engineering, Physics

The authors report an approach that has potential to fabricate dense structures without liquid development. Two kinds of positive tone electron beam resist, 950k PMMA and ZEP 520A (Nippon Zeon), were studied for their properties and behaviors while subjecting them to exposure, thermal development, and reactive ion etching. So far, we have successfully patterned 70 nm half-pitch gratings in both 950k PMMA and ZEP 520A without liquid development.

- by Mohammad Ali Mohammad
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- Polymer Engineering, Physics, Nanoelectronics, Electronics

The field of ‘green technology’ encompasses a continuously evolving group of methods and materials, from techniques for generating energy to non-toxic cleaning products. The present expectation is that this field will bring innovation and... more

- by Hadi Guna
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- PMMA, Green Technology, POF, Polymer Optical Fiber
- by Federica Bondioli
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- Materials Engineering, Chemical Engineering, Materials Science, Nanocomposites

This work describes the preparation and characterization of poly (methyl methacrylate) (PMMA) based gel polymer electrolytes with magnesium triflate (Mg(CF(3)SO(3))(2)) as the ion providing salt. Liquid electrolytes containing 0.4 M Mg(CF(3)SO(3))(2) in solvents comprising different ratios of ethylene carbonate (EC) and diethyl carbonate (DEC) have been prepared at room temperature. The highest conducting electrolyte contains EC and DEC in the weight ratio of 2:1. To the highest conducting liquid electrolyte, 25-50 wt.% PMMA has been added and the mixtures were heated at 80 degrees C for 2 min to form gel polymer electrolytes. The gel electrolyte with composition 40 wt.% PMMA and 60 wt.% of 0.4 M Mg(CF(3)SO(3))(2) in EC:DEC (2:1, w/w) has the highest conductivity of 5.58 x 10(-5)S cm(-1) and activation energy 0.11 eV. The gel polymer electrolyte with highest conductivity at room temperature has Mg(2+) ion transference number of 0.37 and electrochemical stability window 2.42 V. The h...

- by Arjun Sarkar
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- Engineering, Lithium Batteries, Cyclic Voltammetry, PMMA

Background and Aim: Water sorption is one of the most important properties that affects the quality of a prosthesis, and subsequently, the quality of treatment, and patient's quality of life. The aim of this study was to determine and compare the water sorption of two types of poly methyl methacrylate (PMMA) using the injection-molding systems with a traditional acrylic resin base material. Materials and Methods: In this in vitro, experimental study, three groups of PMMA (n=10), consisting of two groups of injection molded PMMA samples (Vertex Castavaria and Ivo-Base High-Impact) were used for two different injection molding techniques and one group of conventional pressure-packed PMMA (Meliodent Heat Cure) was used for the conventional pressure-packed technique. After processing, 30 specimens were stored in distilled water at 37°C for 30 days. The water sorption test was then performed. Statistical analysis was carried out using SPSS version 23.0 via the Kruskal-Wallis and Mann-Whitney tests (α=0.05). Results: The mean value of water sorption was 17.88±1.08 µg/mm 3 for IvoBase specimens, 28.45±2.19µg/mm 3 for Vertex specimens, and 21.76 ±3.26 µg/mm 3 for Meliodent specimens (P<0.001 for Ivobase-Vertex, P <0.007 for Ivobase-Meliodent, and P<0.001 for Vertex-Meliodent). Conclusion: Water sorption of IvoBase was significantly lower than that of other materials. Despite such a significant difference, all of them completely fulfilled the requirements of EN ISO 20795-1:2008.  Cite this article as: Ghasemi E, Mosharraf R, Mirzaei S. Comparison of water sorption of two injection acrylic resins with a conventional pressure-packed acrylic resin.

- by Siavash Mirzaei
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- Prosthodontics, Dental Materials, PMMA, Polymethyl Methacrylate (PMMA)