scholarly journals Effect of thermocycling in a hard denture liner and acrylic resin after different chemical and mechanical polishing

2015 ◽  
Vol 63 (4) ◽  
pp. 397-404
Author(s):  
Graziella Morfim Schramm ALIGNANI ◽  
Juliana Maria Costa Nuñez PANTOJA ◽  
Jessica Mie Ferreira Koyama TAKAHASHI ◽  
Andréa Araújo de VASCONCELLOS ◽  
Marcelo Ferraz MESQUITA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Resistance ◽  
Surface Hardness ◽  
Physical And Mechanical Properties ◽  
Acrylic Resin ◽  
Mechanical Polishing ◽  
Tukey Test ◽  
Before And After ◽  
The Impact ◽  
Resistance Tests

Objective: To evaluate the effect of aging in a hard denture reline (New Truliner) and an acrylic resin (Classic) after chemical and mechanical polishing. Methods: Eighty specimens were made, divided randomly between 8 groups: G1.Acrylic Resin Classic (RAC)/Mechanical Polishing (PM); G2.RAC/PM + thermocycling (TR); G3) RAC/Chemical Polishing (PQ); G4.RAC/PQ + TR; G5.New Truliner (NT)/PM; G6.NT/PM + TR; G7. NT/PQ; G8.NT/PQ + TR. The surface hardness was measured before and after polishing, and after TR. The impact resistance tests were measured after all applied treatments. The data were submitted to ANOVA and Tukey test (a=5%). Results: Regardless of the polishing, it was noted that RAC presented significantly higher surface hardness than NT; PM had higher hardness in both materials compared with PQ; on both polishing, the impact resistance of the RAC was higher than NT. Independently of TR test, the impact resistance of the materials that received PQ was higher than received PM. The PQ caused greater changes in properties than the PM. Conclusion: Aging and chemical and mechanical polishing influenced the physical and mechanical properties of hard denture reline and acrylic resin.

scholarly journals Impact of Aggressive Media on the Properties of Polymeric Coatings with Solidification Products as Fillers

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 793 ◽  
Author(s):  
Jakub Hodul ◽  
Lenka Mészárosová ◽  
Tomáš Žlebek ◽  
Rostislav Drochytka ◽  
Zdeněk Dufek
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Hazardous Waste ◽  
Impact Resistance ◽  
Surface Hardness ◽  
Physical And Mechanical Properties ◽  
Weather Conditions ◽  
Optical Microscope ◽  
Adverse Weather ◽  
Before And After

Dealing with waste materials, particularly hazardous waste, is a serious problem. Disposal areas keep growing, and the costs incurred are high. Disposing of such waste reduces negative environmental impacts and offers considerable financial savings. This paper focuses on the possibilities of incorporating pollutants found in hazardous wastes as fillers in coatings based on polymers (epoxide and polyurethane). These coatings are intended mainly for concrete and metal bases and offer secondary protection against adverse weather conditions. Important physical and mechanical properties of the newly developed materials were determined; they include surface hardness, impact resistance, tensile properties, and chemical resistance. These properties were also compared to those of the reference filler. At the same time, the influence of aggressive media on the properties of these materials was observed, in particular on flexural characteristics. The microstructures of the developed coatings were tested using a high-resolution optical microscope, before and after exposure to the chemicals. The positive effect of using progressive fillers, such as solidified hazardous waste (a solidification product (SF)), was witnessed by their constructive contribution to the materials’ physical and mechanical properties. The use of solidification products is unambiguously advantageous from technical, ecological, and economical stand points (utilization of hazardous waste as a progressive filler instead of landfilling, improvement of tensile properties, reduction in the price of coating system, and incorporation of the pollutants into the polymer matrix).

Study on Mechanical Properties of Styrene-ethylene/butylene-styrene/polystyrene Blends

2011 ◽  
Vol 396-398 ◽  
pp. 1422-1425
Author(s):  
Xiao Ming Sang ◽  
Lei Zhang ◽  
Run Zeng Wang ◽  
Xing Gang Chen ◽  
Man An ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Impact Resistance ◽  
Melt Blending ◽  
Maximum Value ◽  
Izod Impact ◽  
The Impact ◽  
Resistance Tests ◽  
Scanning Electron ◽  
Number Of Particles

The styrene-ethylene/butylene-styrene/polystyrene (SEBS/PS) blends were prepared by melt blending. The mechanical properties of PS/SEBS blends were influenced by the increase of SEBS contents. When the content of SEBS increased to 13 wt%, the impact strength of SEBS/PS blends boosted the maximum value. Young’s modulus and tensile strength of SEBS/PS blends decreased with the increase of SEBS. The fracture surfaces obtained during Izod impact resistance tests were obtained by scanning electron microscopy (SEM). The results indicated that the number of particles of SEBS dispersed in PS matrix. The diameters of particles of SEBS were about 1.5-3 µm. SEBS/PS blends absorbed more energy than pure PS during impact resistance tests.

Quality of surface finish on furniture doors of MDF board

2019 ◽  
Vol 105 ◽  
pp. 102-106
Author(s):  
GABRIELA SLABEJOVÁ ◽  
MÁRIA ŠMIDRIAKOVÁ ◽  
IVAN VOZAF
Keyword(s):  
Mechanical Properties ◽  
Surface Finish ◽  
Impact Resistance ◽  
Physical And Mechanical Properties ◽  
Coating Material ◽  
Film Hardness ◽  
The Impact

Quality of Surface Finish on Furniture Doors of MDF Board. The paper deals with the assessment of the quality of furniture door surface. The properties were tested on the following types of the surface finish on MDF doors: PVC foil (glossy and matt), acrylic foil, and PUR pigmented coating material. The following physical and mechanical properties of the surfaces were assessed: the film hardness, the impact resistance, and the resistance against scuffing. The polyurethane surface finish and the glossy PVC foil achieved the same film hardness. The impact resistance of the polyurethane finish was significantly lower than the impact resistance of the PVC foils and the acrylic foil. The resistance against scuffing was lower for the polyurethane finish if compared to the foiled surfaces.

scholarly journals Effect of Oil Paint Addition on Impact Strength of the Scleral Part of the Acrylic Ocular Prosthesis

2018 ◽  
Vol 12 (1) ◽  
pp. 946-951
Author(s):  
Firas Abd Kati
Keyword(s):  
Mechanical Properties ◽  
Titanium Dioxide ◽  
Impact Strength ◽  
Physical And Mechanical Properties ◽  
Acrylic Resin ◽  
Control Group ◽  
Ocular Prosthesis ◽  
Acrylic Resins ◽  
Oil Paints ◽  
The Impact

Background: For many dental and facial restorations, acrylic resins are the materials of choice because of their appropriate physical and mechanical properties. When making the ocular prosthesis from such materials, it is essential to add the perfect shade in order to match the colour of normal eye. This, however, might have a significant effect on the mechanical properties of acrylic resins. Objective: The purpose of this study was to assess the effect of adding the white oil paint (titanium dioxide) to clear acrylic resins on their impact strength. Methods: 20 samples were constructed from heat cured acrylic resins, and divided into two groups (control and experimental) and each group had 10 samples. The first group was made from clear acrylic resin without the addition of white oil paints, and the second group (experimental) comprised the addition of 1 ml of the white oil paints to acrylic samples. Such samples were prepared with dimensions of (80 mm X10 mm X4 mm) length, width, and thickness, respectively. All the samples were tested by the Charpy's impact strength test. They were exposed to the load till the fracture occurred. All the values were analyzed using SPSS version 20, and the independent T-test was used for comparison between the 2 groups. Results: A statistically significant decrease (P-value < 0.001) was found in the impact strength of acrylic resins after the addition of titanium dioxide oil paints (experimental group: 5.97 + 1.11, control group: 9.42+1.32 KJ/M2). Conclusion: This study concluded that the addition of titanium dioxide oil paint significantly reduces the impact of strength of the acrylic resin. It is suggested to use different stains which will have no negative effect on impact strength of the acrylic resin.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

scholarly journals Effect of SWCNT-Tuball Paper on the Lightning Strike Protection of CFRPs and Their Selected Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Copper Foil ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Lightning Strike ◽  
Single Wall Carbon Nanotubes ◽  
Carbon Fibre Reinforced Polymer ◽  
The Impact

The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt% or 90 wt% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil.

scholarly journals Damage Evolution of Granodiorite after Heating and Cooling Treatments

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Mohamed Gomah ◽  
Guichen Li ◽  
Salah Bader ◽  
Mohamed Elkarmoty ◽  
Mohamed Ismael
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Failure Mode ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Physical Parameters ◽  
Slow Cooling ◽  
Heating And Cooling ◽  
Natural Rock ◽  
The Impact

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

scholarly journals Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Heat Treatments ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Before And After ◽  
The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

Phase Morphology, Thermal and Mechanical Properties of Compatibilized Nylon12/Natural Rubber Blends Using PS/MNR

2013 ◽  
Vol 844 ◽  
pp. 53-56
Author(s):  
Saravalee Saengthaveep ◽  
Sadhan C. Jana ◽  
Rathanawan Magaraphan
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Moisture Absorption ◽  
Rubber Particle ◽  
Impact Resistance ◽  
Phase Morphology ◽  
Thermal And Mechanical Properties ◽  
Binary Blend ◽  
Polyamide 12 ◽  
The Impact

To produce a tough material for application demanding high impact resistance and low moisture absorption, melt blending of Nylon12 (Polyamide 12, PA12) and natural rubber (NR) was carried out in a brabender plasticorder at 210 °C with rotor speed of 70 rpm in the presence of polystyrene/maleated natural rubber (PS/MNR) blend as a compatibilizer. The effect of compatibilizer content (1, 3, 5, 7 and 10 phr) on phase morphology, thermal, and mechanical properties of [Nylon12/NR]/[PS/MNR] blends was investigated by using SEM, DSC, and Izod impact tester, respectively. The result revealed that PS/MNR blend improved the compatibility of Nylon12/NR blends efficiently due to the presence of amide linkage at the interfaces from the reaction between the reactive groups of MNR and the NH2 end groups of Nylon12 during mixing. A fine phase morphology (good dispersion and small dispersed phase size of NR domains in Nylon12 matrix) of [Nylon12/NR]/[PS/MNR] blends was observed at the optimum compatibilizer content of 7 phr, relating to the improvement of mechanical property. The impact energy of [Nylon12/NR]/[PS/MNR] blends was 503 J/m higher than that of neat Nylon12 (115 J/m) and Nylon12/NR binary blend (241 J/m) due to the toughening effect of rubber and proper morphology. The melting temperature of all blends did not change obviously from thermal analysis. However, the presence of rubber particle obstructed the crystallization of Nylon12 phase, leading to the decreasing of %crystallinity from 93% to around 70%.

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