scholarly journals A Generalized Approach for Evaluating the Mechanical Properties of Polymer Nanocomposites Reinforced with Spherical Fillers

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 830
Author(s):  
Julio Cesar Martinez-Garcia ◽  
Alexandre Serraïma-Ferrer ◽  
Aitor Lopeandía-Fernández ◽  
Marco Lattuada ◽  
Janak Sapkota ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymeric Nanocomposites ◽  
Mechanical Reinforcement ◽  
Future Studies ◽  
Three Phase ◽  
Theoretical Predictions ◽  
Filler Network ◽  
New Research ◽  
Good Agreement ◽  
Research Avenue

In this work, the effective mechanical reinforcement of polymeric nanocomposites containing spherical particle fillers is predicted based on a generalized analytical three-phase-series-parallel model, considering the concepts of percolation and the interfacial glassy region. While the concept of percolation is solely taken as a contribution of the filler-network, we herein show that the glassy interphase between filler and matrix, which is often in the nanometers range, is also to be considered while interpreting enhanced mechanical properties of particulate filled polymeric nanocomposites. To demonstrate the relevance of the proposed generalized equation, we have fitted several experimental results which show a good agreement with theoretical predictions. Thus, the approach presented here can be valuable to elucidate new possible conceptual routes for the creation of new materials with fundamental technological applications and can open a new research avenue for future studies.

Effective Thermal Conductvity of Three-Phase Soils

2012 ◽  
Author(s):  
Fabio Gori ◽  
Sandra Corasaniti
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Heat Fluxes ◽  
Water Volume ◽  
Two Phase ◽  
Empirical Constant ◽  
Three Phase ◽  
Theoretical Predictions ◽  
Porosity Ratio ◽  
Good Agreement

The aim of the present paper is to determine the effective thermal conductivity of three-phase soils, made of a quasi-spherical solid grain, and surrounded by two phase, which can be water and air or water and ice. The effective thermal conductivity is obtained theoretically by integrating the conduction equation under the thermal distribution of parallel heat fluxes in steady-state. The effective thermal conductivity is evaluated at a given degree of porosity (ratio between the void volume and the total one) and different degrees of saturation (ratio between the water volume and the void one) from dryness up to saturation. Comparisons between experimental data and theoretical predictions confirm that the present model can predict the effective thermal conductivity with a fairly good agreement without using any empirical constant.

Theoretical Prediction and Experimental Study of Mechanical Properties for Random and Magnetically Aligned Single-Walled Carbon Nanotube/Epoxy Composites

2003 ◽  
Vol 791 ◽  
Author(s):  
Ben Wang ◽  
Ravi Shankar ◽  
Zhiyong Liang ◽  
Zhi Wang ◽  
Chuck Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
High Performance ◽  
Experimental Results ◽  
Reinforced Composites ◽  
Polymeric Nanocomposites ◽  
Single Walled Carbon ◽  
Theoretical Predictions ◽  
Walled Carbon Nanotubes ◽  
Magnetically Aligned

ABSTRACTSingle-walled carbon nanotubes (SWNTs) have exceptional mechanical and functional properties. Many researchers consider SWNTs as the most promising reinforcement for realizing the optimal structural and multifunctional potential of the next generation of high performance nanocomposites. However, due to poor dispersion, weak interfacial bonding and deficient tube orientation, current nanotube-based nanocomposites fail to realize their anticipated properties. A new approach was developed by the authors to use preformed nanotube tube networks (called buckypapers) and a resin infiltration method for producing bulk polymeric nanocomposites with controlled nanostructure and high tube loading. Desired tube alignment in nanocomposites can be achieved by using magnetically aligned carbon nanotube buckypapers, in which SWNTs will tend to align along the direction of applied magnetic field. The mechanical properties of the resultant nanocomposites have been tested. The storage modulus of the magnetically aligned nanocomposites is as high as 47 GPa, which is one of the highest reported values of nanotube-reinforced composites.In this research, we investigated the influences of tube dispersion, loading and orientation on the mechanical properties of SWNT-reinforced composites. Random and aligned discontinuous reinforcement models of composites were applied to predict the tensile moduli of both individually dispersed SWNT-based and SWNT rope-based nanocomposites. The nanostructural parameters used in the calculation models were determined based on our experimental observations. Comparisons between theoretical estimates and experimental results have shown that the formation of SWNT ropes in the composites has a significant influence on the mechanical properties. The experimental results of the both random and aligned SWNT rope composites are in good agreement with the theoretical predictions.

Impact of Natural and Synthetic Nanofibres Presence in Polymeric Composites on Mechanical Properties

2014 ◽  
Vol 1613 ◽  
pp. 133-139 ◽  
Author(s):  
Martin Seidl ◽  
Jiří Bobek ◽  
Jiří Habr ◽  
Petr Lenfeld ◽  
Luboš Běhálek
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Coupling Agent ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Polymeric Composites ◽  
Polymeric Nanocomposites ◽  
Cellulose Fibres ◽  
Three Phase ◽  
Natural And Synthetic

ABSTRACTThis study deals with evaluation of mechanical properties (tensile, flexural and impact strength), that verified reinforcing potential of nanofibres in polymeric composites and their applicability in dependence on the filler content of nanofibres of natural and synthetic origin. Considering the hydrophilic nature of natural nanofibres and hydrophobic polypropylene matrix was applied chemical modification that ensures effective interlock of nanofibres with the matrix, namely maleic anhydride grafted polypropylene and ionic modifier. Polymeric nanocomposites were prepared by twin screw extrusion that made possible mixing of all three components together. After cooling in water bath the composites were cut on pellets and dried for further injection moulding. The specimens were made of two- or three-phase component systems that included PP matrix, coupling agent in the volume of 4 wt.% and reinforcing nanofillers in the volume of 2, 4 and 6 wt.%. The presence of nanoparticles and coupling agents had not unambiguous impact on analysed mechanical properties. Coupling agent presence was dominant for impact strength, however, flexural and tensile properties were influenced mainly by the nanofiller type and origin. The dispersed phase and compatibilizer improved flexural modulus but tensile modulus of pure PP were not achieved by three-phase composite, not even with the highest analysed nanoparticle load. Cellulose fibres proved as more proper than the synthetic ones not only for their biodegradability and renewability but for their better toughness as well.

scholarly journals Experimental study on mechanical properties for a three-phase polymer composite reinforced by glass fibers and titanium oxide particles

2011 ◽  
Vol 33 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Nguyen Dinh Duc ◽  
Dinh Khac Minh
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Titanium Oxide ◽  
Polymer Composite ◽  
Glass Fibers ◽  
Three Phase ◽  
Oxide Particles ◽  
Elastic Modules ◽  
Theoretical Results ◽  
Good Agreement

Nowadays, composite materials are applied in many fields. The physico-mechanical properties of the material can be improved by adding reinforced fibers and particles. Many scientists pay attention to the calculation for elastic modules of three-phase composite materials. This report presents the experimental results for some elastic modules of three-phase polymer composite reinforced with glass fibers and titanium oxide particles of different volume ratios. A comparison between experimental and theoretical results shows good agreement.

scholarly journals Nanostructure, Self-Assembly, Mechanical Properties, and Antioxidant Activity of a Lupin-Derived Peptide Hydrogel

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 294
Author(s):  
Raffaele Pugliese ◽  
Anna Arnoldi ◽  
Carmen Lammi
Keyword(s):  
Mechanical Properties ◽  
Antioxidant Activity ◽  
Self Assembly ◽  
Antioxidant Activities ◽  
Functional Materials ◽  
Cd Spectroscopy ◽  
Beneficial Effects ◽  
Naturally Occurring ◽  
New Research ◽  
Peptide Hydrogel

Naturally occurring food peptides are frequently used in the life sciences due to their beneficial effects through their impact on specific biochemical pathways. Furthermore, they are often leveraged for applications in areas as diverse as bioengineering, medicine, agriculture, and even fashion. However, progress toward understanding their self-assembling properties as functional materials are often hindered by their long aromatic and charged residue-enriched sequences encrypted in the parent protein sequence. In this study, we elucidate the nanostructure and the hierarchical self-assembly propensity of a lupin-derived peptide which belongs to the α-conglutin (11S globulin, legumin-like protein), with a straightforward N-terminal biotinylated oligoglycine tag-based methodology for controlling the nanostructures, biomechanics, and biological features. Extensive characterization was performed via Circular Dichroism (CD) spectroscopy, Fourier Transform Infrared spectroscopy (FT-IR), rheological measurements, and Atomic Force Microscopy (AFM) analyses. By using the biotin tag, we obtained a thixotropic lupin-derived peptide hydrogel (named BT13) with tunable mechanical properties (from 2 to 11 kPa), without impairing its spontaneous formation of β-sheet secondary structures. Lastly, we demonstrated that this hydrogel has antioxidant activity. Altogether, our findings address multiple challenges associated with the development of naturally occurring food peptide-based hydrogels, offering a new tool to both fine tune the mechanical properties and tailor the antioxidant activities, providing new research directions across food chemistry, biochemistry, and bioengineering.

scholarly journals An Additive Model to Predict the Rheological and Mechanical Properties of Polypropylene Blends Made by Virgin and Reprocessed Components

Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Francesco Paolo La Mantia ◽  
Maria Chiara Mistretta ◽  
Vincenzo Titone
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Additive Model ◽  
Industrial Process ◽  
Theoretical Predictions ◽  
Experimental Values ◽  
Polypropylene Blends ◽  
Polypropylene Sample

In this work, an additive model for the prediction of the rheological and mechanical properties of monopolymer blends made by virgin and reprocessed components is proposed. A polypropylene sample has been reprocessed more times in an extruder and monopolymer blends have been prepared by simulating an industrial process. The scraps are exposed to regrinding and are melt reprocessed before mixing with the virgin polymer. The reprocessed polymer is, then, subjected to some thermomechanical degradation. Rheological and mechanical experimental data have been compared with the theoretical predictions. The results obtained showed that the values of this simple additive model are a very good fit for the experimental values of both rheological and mechanical properties.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

scholarly journals Pre-treatments of pre-consumer cotton-based textile waste for production of textile fibres in the cold NaOH(aq) and cellulose carbamate processes

Cellulose ◽  
2021 ◽  
Author(s):  
Marjo Määttänen ◽  
Maria Gunnarsson ◽  
Helena Wedin ◽  
Sara Stibing ◽  
Carina Olsson ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Raw Material ◽  
Textile Waste ◽  
Future Studies ◽  
Degree Of Polymerisation ◽  
Textile Fibres ◽  
Cellulose Carbamate ◽  
Regenerated Fibres ◽  
Inorganic Content

AbstractRecycling of textiles is of importance due to the large amount of waste generated from the increasing consumption and use worldwide. Cotton-rich pre-consumer textiles are considered as potential raw material for production of man-made regenerated fibres, but demands purification from the blends with synthetic fibres as well as the dyes and finishing chemicals. In this study we explore the use of different pre-treatments of pre-consumer textiles to meet specific parameters for production of fibres in the cold NaOH(aq) or cellulose carbamate process. The pre-treatments consisted of different bleaching sequences and were performed on both uncoloured and coloured pre-consumer textiles. For the uncoloured textile, degree of polymerisation and amount of inorganic content was efficiently reduced making the material suitable for both the cold NaOH(aq) and the cellulose carbamate process. In case of the coloured textile, the pre-treatments were able to remove the dye and decrease the inorganic content as well as reduce the degree of polymerisation but only sufficiently enough for production of fibres in the cellulose carbamate process. The work was able to prove a fibre-to-fibre concept while further optimisation of the regeneration steps is expected to improve the mechanical properties of the produced fibres in future studies.

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