Mechanical behavior of particle-reinforced polyurethane composites for load-bearing drives

2019 ◽  
Vol 6 (3) ◽  
pp. 33-41
Author(s):  
Anna Porąbka ◽  
Vasiliki-Maria Archodoulaki ◽  
Jadwiga Laska
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Mechanical Behavior ◽  
Reference Materials ◽  
Physical And Mechanical Properties ◽  
Vibration Damping ◽  
Load Bearing ◽  
Ceramic Particles ◽  
Polyurethane Composites ◽  
Properties Of Composites

Two series of polyurethane composites were prepared using NDI- and MDI-based prepolymers and common polyol. NDI-based polyurethane is generally resistant to mechanical wear and rebound-resilient whereas MDI-based PU has cushioning and vibration damping features, and both types can be used as a matrix for load-bearing composites. The objective of this study was to compare the mechanical properties of composites containing 5% vol. of ceramic particles prepared with the use of the mentioned PU systems, and unmodified commercial materials. The effect of various ceramic particles on physical and mechanical properties was studied. The results showed that the mechanical properties changed in comparison to reference materials: E’ improved, and impact strength performed favorably in certain materials. Both the tensile strengths and the elongations at break of the composites were found to decrease with the content of ceramic particles; however, the hardness increased gradually. Since ceramic particles offer better stiffness and hardness, the selected composites could be a viable alternative to the pure commercial PUs available in the industry.

Wear behaviour of polyurethane composites with respect to the other mechanical properties

2014 ◽  
Vol 11 (2) ◽  
pp. 139-146
Author(s):  
Anna Porąbka ◽  
Vasiliki-Maria Archodoulaki ◽  
Wolfgang Molnar ◽  
Jadwiga Laska
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Wear Behaviour ◽  
Matrix Composites ◽  
Different Temperatures ◽  
Polyurethane Composites ◽  
Polyurethane Matrix ◽  
Properties Of Composites

Two series of polyurethane matrix composites were prepared. As generally resistant to wear, the PUs can be used as matrices for wear protective and load-bearing composites. The objective of this study was to compare the mechanical properties of composites containing 5% vol. of selected ceramic particles, and unmodified PUs. The effect of various particles on physical and mechanical properties was studied. The results showed that the mechanical properties changed compared to reference materials: modulus improved in certain materials and in different temperatures, revealing the favourable influence of FA and SiO2 particles. In turn, Rm and wear resistance decreased with the type and shape of filler.

Basic Physical and Mechanical Properties of Composites Based on Three Different Cements

2016 ◽  
Vol 677 ◽  
pp. 186-190 ◽  
Author(s):  
Monika Čáchová ◽  
Eva Vejmelková ◽  
Kateřina Šestáková ◽  
Pavel Reiterman ◽  
Martin Keppert ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Open Porosity ◽  
Mercury Porosimetry ◽  
Physical And Mechanical Properties ◽  
Mineralogical Composition ◽  
Physical Parameters ◽  
Vacuum Saturation ◽  
Saturation Method ◽  
Properties Of Composites

This article is focused on cement based composites. Two cements differing in mineralogical composition are utilised as main binder in composites mixtures. Results of measured physical parameters of studied materials are presented. For the sake of comparison, a reference material with Portland cement was also prepared. Basic physical properties (measured by water vacuum saturation method and by helium pycnometry), characterizations of pore system (determined by mercury porosimetry) and mechanical properties are the matter of this study. Composites show various open porosity; the results of open porosity of materials containing special cements show higher values, in comparison with composite based on Portland cement. This fact of course influences other material characteristics - mainly mechanical properties.

Effect of Wood Filler Concentration on Physical and Mechanical Properties of PLA-Based Composites

2021 ◽  
Vol 887 ◽  
pp. 110-115
Author(s):  
G.A. Sabirova ◽  
R.R. Safin ◽  
N.R. Galyavetdinov
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Composite Materials ◽  
Impact Strength ◽  
Wood Flour ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Filler Concentration ◽  
High Concentration

This paper presents the findings of experimental studies of the physical and mechanical properties of wood-filled composites based on polylactide (PLA) and vegetable filler in the form of wood flour (WF) thermally modified at 200-240 °C. It also reveals the dependence of the tensile strength, impact strength, bending elastic modulus, and density of composites on the amount of wood filler and the temperature of its thermal pre-modification. We established that an increase in the concentration of the introduced filler and the degree of its heat treatment results in a decrease of the tensile strength, impact strength and density of composite materials, while with a lower binder content, thermal modification at 200 °C has a positive effect on bending elastic modulus. We also found that 40 % content of a wood filler heated to 200 °C is sufficient to maintain relatively high physical and mechanical properties of composite materials. With a higher content of a wood filler, the cost can be reduced but the quality of products made of this material may significantly deteriorate. However, depending on the application and the life cycle of this product, it is possible to develop a formulation that includes a high concentration of filler.

Secondary Structures and Mechanical Properties of Biomimetic Protein Polymers

2009 ◽  
Author(s):  
Weibing Teng ◽  
Joseph Cappello ◽  
Xiaoyi Wu
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Mechanical Behavior ◽  
Half Life ◽  
Secondary Structures ◽  
Load Bearing ◽  
Protein Polymers ◽  
Human Arteries ◽  
Good Biocompatibility ◽  
Polypeptide Sequences

Silk may possess superior mechanical strength while its resilience is very poor. In contrast, elastin in human arteries is very soft but extremely durable with an estimated half-life of 70 years. By combing polypeptide sequences derived from native silk and elastin, we have produced a series of silk-elastin-like proteins (SELPs), which have displayed a set of outstanding properties such as good biocompatibility and controllable biodegradation rates [1]. In this study, we will examine the crystallization of the silk-like blocks and the crosslinking of the elastin-like blocks, as well as their influences on the mechanical behavior of SELPs. The ultimate goal of this study is to explore the potential of SELPs for applications in the engineering of load-bearing tissues such as arteries.

Physical and Mechanical Properties of Composites with Aluminum Alloy Matrix Designed for Metal Forming

2013 ◽  
Vol 212 ◽  
pp. 59-62 ◽  
Author(s):  
Jerzy Myalski ◽  
Jakub Wieczorek ◽  
Adam Płachta
Keyword(s):  
Mechanical Properties ◽  
Metal Forming ◽  
Matrix Material ◽  
Physical And Mechanical Properties ◽  
Mechanical Mixing ◽  
Alloy Matrix ◽  
Segregation Process ◽  
The Matrix ◽  
Glass Carbon ◽  
Properties Of Composites

The change of matrix and usage of the aluminum alloys designed for the metal forming in making the composite suspension allows to extend the processing possibility of this type of materials. The possibility of the metal forming of the composites obtained by mechanical mixing will extend the range of composite materials usage. Applying of the metal forming e.g. matrix forging, embossing, pressing or rolling, will allow to remove the incoherence of the structure created while casting and removing casting failures. In order to avoid the appearance of the casting failures the homogenization conditions need to be changed. Inserting the particles into the matrix influences on the shortening of the composite solidification. The type of the applied particles influenced the sedimentation process and reinforcement agglomeration in the structure of the composite. Opposite to the composites reinforced with one-phase particles applying the fasess mixture (glassy carbon and silicon carbide) triggered significant limitation in the segregation process while casting solidification. Inserting the particles into the AW-AlCu2SiMn matrix lowers the mechanical properties tension and impact value strength. The most beneficial mechanical properties were gained in case of heterofasess composites reinforced with the particle mixture of SiC and glass carbon. The chemical composition of the matrix material (AW-AlCu2SiMn) allows to increase additionally mechanical characteristics by the precipitation hardening reached through heat casting forming.

scholarly journals Physical and mechanical properties of composites based on hemp shives and lime

2018 ◽  
Vol 49 ◽  
pp. 00010 ◽  
Author(s):  
Przemysław Brzyski ◽  
Grzegorz Łagód
Keyword(s):  
Mechanical Properties ◽  
Thermal Insulation ◽  
Thermal Conductivity Coefficient ◽  
Positive Impact ◽  
Physical And Mechanical Properties ◽  
Wall Material ◽  
High Porosity ◽  
Plant Origin ◽  
Timber Frame ◽  
Properties Of Composites

One of the objectives of sustainable development in construction is the use of low-processed materials. They have a positive impact on the ecological balance of the building throughout the entire life cycle. Examples of such materials are materials of plant origin - straw, shives, cellulose fibers. They are used as thermal insulation or wall material. In recent years, hemp shives are increasingly used as a component of a lime-based composite, which performs the function of wall filling in timber frame constructions. The shives, due to the high porosity, determine the high thermal insulation properties of the composite. The physico-mechanical properties of the composite can be modified depending on various factors, including the ratio of hemp shives to the binder. The lime binder, in turn, can be modified by hydraulic and pozzolan additives. The paper presents mechanical properties (compressive and flexural strength) as well as physical properties (density, porosity, thermal conductivity coefficient, absorbability) of composites with various proportions of hemp shives of the Bialobrzeskie variety to the lime binder modified with Portland cement and metakaolinite.

The Influence of the Long-Term Storage of Hardwood on the Selected Physical and Mechanical Properties in View of Pulping

2016 ◽  
Vol 688 ◽  
pp. 10-16
Author(s):  
Blažej Seman ◽  
Anton Geffert ◽  
Jarmila Geffertova
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Continuous Production ◽  
Beech Wood ◽  
Physical And Mechanical Properties ◽  
Long Term Storage ◽  
The Impact ◽  
Term Storage ◽  
Strength In Bending

Wood is loosely stored to ensure continuous production inside paper mills where it is exposed to the effect of external factors. The impact of storage leads to some changes of mechanical and physical properties of wood, but these changes are not the same in all specimens. In this paper, it has been observed that the long term storage of wood influences the impact strength in bending and the permeability of wood for fluids. During the storage, there was a decrease of impact strength in bending of poplar heartwood by 28.3% and oak by 22.1% and mature beech wood by 37.3%. Also, there was decreased a permeability of wood, poplar sapwood 18.3 % and heartwood of 53.9%; oak sapwood by 20.0% and heartwood by 20.3%; beech sapwood 45.8% and mature wood by 48.2%. By decrease of the observed properties of the stored wood, a deterioration a quality of produced pulp can be expected (a higher Kappa number, amount reject and decrease the mechanical properties of pulp).

scholarly journals Effect of repeated disinfections by microwave energy on the physical and mechanical properties of denture base acrylic resins

2009 ◽  
Vol 20 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Rafael Leonardo Xediek Consani ◽  
Douglas Duenhas de Azevedo ◽  
Marcelo Ferraz Mesquita ◽  
Wilson Batista Mendes ◽  
Paulo César Saquy
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
Knoop Hardness ◽  
Microwave Energy ◽  
Bending Test ◽  
Denture Base ◽  
Acrylic Resins ◽  
The Impact

The present study evaluated the effect of repeated simulated microwave disinfection on physical and mechanical properties of Clássico, Onda-Cryl and QC-20 denture base acrylic resins. Aluminum patterns were included in metallic or plastic flasks with dental stone following the traditional packing method. The powder/liquid mixing ratio was established according to the manufacturer's instructions. After water-bath polymerization at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling and finished. Each specimen was immersed in 150 mL of distilled water and underwent 5 disinfection cycles in a microwave oven set at 650 W for 3 min. Non-disinfected and disinfected specimens were subjected to the following tets: Knoop hardness test was performed with 25 g load for 10 s, impact strength test was done using the Charpy system with 40 kpcm, and 3-point bending test (flexural strength) was performed at a crosshead speed of 0.5 mm/min until fracture. Data were analyzed statistically by ANOVA and Tukey's test (α= 0.05%). Repeated simulated microwave disinfections decreased the Knoop hardness of Clássico and Onda-Cryl resins and had no effect on the impact strength of QC-20. The flexural strength was similar for all tested resins.

Influence of Sic and Al2O3 Particulate Reinforcement on the Mechanical Properties of ZA27 Metal Matrix Composites

2019 ◽  
Vol 969 ◽  
pp. 122-127
Author(s):  
B.N. Anjan ◽  
G.V. Preetham Kumar
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Matrix Alloy ◽  
Stir Casting ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Weight Percentage ◽  
Casting Technique ◽  
Fine Microstructure ◽  
Properties Of Composites

Zinc aluminum based matrix composites reinforced with SiC and Al2O3 particles have significant applications in the automobile field. Stir casting method followed by squeeze process was used for fabrication. ZA27 composites reinforced with SiC and Al2O3 particles (20-50µm) in various weight percentage (wt%) ranges from 0-10 in a step of 5 each was fabricated. OM, SEM and EDS analysis of microstructures obtained for matrix alloy and reinforced composites were performed in order to know the effect of varying wt% on physical and mechanical properties of composites. Squeeze casting technique shows better features such as fine microstructure as a result of low porosity and good bonding between matrix and reinforcement. Addition of reinforcements decreased the densities of matrix alloy. SiC reinforced composites showed better results as compared with Al2O3 reinforced ones. Hardness and ultimate tensile strength value of 10 wt% reinforced composites showed improved results.

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