scholarly journals The Effect of Microcellular Structure on the Dynamic Mechanical Thermal Properties of High-Performance Nanocomposite Foams Made of Graphene Nanoplatelets-Filled Polysulfone

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 437
Author(s):  
Marcelo Antunes ◽  
Hooman Abbasi ◽  
José Ignacio Velasco
Keyword(s):  
Relative Density ◽  
Supercritical Co2 ◽  
Cellular Structure ◽  
High Performance ◽  
Graphene Nanoplatelets ◽  
Cellular Structures ◽  
Density Range ◽  
Specific Storage ◽  
Glass Transition Temperatures ◽  
Nanocomposite Foams

Polysulfone nanocomposite foams containing variable amounts of graphene nanoplatelets (0–10 wt%) were prepared by water vapor-induced phase separation (WVIPS) and supercritical CO2 (scCO2) dissolution. WVIPS foams with two ranges of relative densities were considered, namely, between 0.23 and 0.41 and between 0.34 and 0.46. Foams prepared by scCO2 dissolution (0.0–2.0 wt% GnP) were obtained with a relative density range between 0.35 and 0.45. Although the addition of GnP affected the cellular structure of all foams, they had a bigger influence in WVIPS foams. The storage modulus increased for all foams with increasing relative density and GnP’s concentration, except for WVIPS PSU-GnP foams, as they developed open/interconnected cellular structures during foaming. Comparatively, foams prepared by scCO2 dissolution showed higher specific storage moduli than similar WVIPS foams (same relative density and GnP content), explained by the microcellular structure of scCO2 foams. As a result of the plasticizing effect of CO2, PSU foams prepared by scCO2 showed lower glass transition temperatures than WVIPS foams, with the two series of these foams displaying decreasing values with incrementing the amount of GnP.

scholarly journals Effects of Graphene Nanoplatelets and Cellular Structure on the Thermal Conductivity of Polysulfone Nanocomposite Foams

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 25 ◽  
Author(s):  
Hooman Abbasi ◽  
Marcelo Antunes ◽  
José Ignacio Velasco
Keyword(s):  
Thermal Conductivity ◽  
Relative Density ◽  
Supercritical Co2 ◽  
Cellular Structure ◽  
Graphene Nanoplatelets ◽  
Nanocomposite Foams ◽  
Increasing Trend ◽  
The Impact ◽  
Opening Up ◽  
Enhanced Thermal Conductivity

Polysulfone (PSU) foams containing 0–10 wt% graphene nanoplatelets (GnP) were prepared using two foaming methods. Alongside the analysis of the cellular structure, their thermal conductivity was measured and analyzed. The results showed that the presence of GnP can affect the cellular structure of the foams prepared by both water vapor induced phase separation (WVIPS) and supercritical CO2 (scCO2) dissolution; however, the impact is greater in the case of foams prepared by WVIPS. In terms of thermal conductivity, the analysis showed an increasing trend by incrementing the amount of GnP and increasing relative density, with the tortuosity of the cellular structure, dependent on the used foaming method, relative density, and amount of GnP, playing a key role in the final value of thermal conductivity. The combination of all these factors showed the possibility of preparing PSU-GnP foams with enhanced thermal conductivity at lower GnP amount by carefully controlling the cellular structure and relative density, opening up their use in lightweight heat dissipators.

scholarly journals Design and Optimization of Graded Cellular Structures With Triply Periodic Level Surface-Based Topological Shapes

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Dawei Li ◽  
Ning Dai ◽  
Yunlong Tang ◽  
Guoying Dong ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Density Distribution ◽  
Relative Density ◽  
Cellular Structure ◽  
Scaling Laws ◽  
Functionally Graded ◽  
Cellular Structures ◽  
Level Surface ◽  
Implicit Functions ◽  
Design And Optimization ◽  
Triply Periodic

Periodic cellular structures with excellent mechanical properties widely exist in nature. A generative design and optimization method for triply periodic level surface (TPLS)-based functionally graded cellular structures is developed in this work. In the proposed method, by controlling the density distribution, the designed TPLS-based cellular structures can achieve better structural or thermal performances without increasing its weight. The proposed technique can be divided into four steps. First, the modified 3D implicit functions of the triply periodic minimal surfaces are developed to design different types of cellular structures parametrically and generate spatially graded cellular structures. Second, the numerical homogenization method is employed to calculate the elastic tensor and the thermal conductivity tensor of the cellular structures with different densities. Third, the optimal relative density distribution of the object is computed by the scaling laws of the TPLS-based cellular structures added optimization algorithm. Finally, the relative density of the numerical results of structure optimization is mapped into the modified parametric 3D implicit functions, which generates an optimum lightweight cellular structure. The optimized results are validated subjected to different design specifications. The effectiveness and robustness of the obtained structures is analyzed through finite element analysis and experiments. The results show that the functional gradient cellular structure is much stiffer and has better heat conductivity than the uniform cellular structure.

scholarly journals Foaming Behaviour, Structure, and Properties of Polypropylene Nanocomposites Foams

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
M. Antunes ◽  
V. Realinho ◽  
J. I. Velasco
Keyword(s):  
Electrical Conductivity ◽  
Cellular Structure ◽  
Structure And Properties ◽  
Reinforcement Effect ◽  
Specific Storage ◽  
Structure And Morphology ◽  
Nanocomposite Foams ◽  
Polypropylene Nanocomposites ◽  
Carbon Nanofibre

This work presents the preparation and characterization of compression-moulded montmorillonite and carbon nanofibre-polypropylene foams. The influence of these nanofillers on the foaming behaviour was analyzed in terms of the foaming parameters and final cellular structure and morphology of the foams. Both nanofillers induced the formation of a more isometric-like cellular structure in the foams, mainly observed for the MMT-filled nanocomposite foams. Alongside their crystalline characteristics, the nanocomposite foams were also characterized and compared with the unfilled ones regarding their dynamic-mechanical thermal behaviour. The nanocomposite foams showed higher specific storage moduli due to the reinforcement effect of the nanofillers and higher cell density isometric cellular structure. Particularly, the carbon nanofibre foams showed an increasingly higher electrical conductivity with increasing the amount of nanofibres, thus showing promising results as to produce electrically improved lightweight materials for applications such as electrostatic painting.

Behaviour of Cellular Structures under Impact Loading a Computational Study

2007 ◽  
Vol 566 ◽  
pp. 53-60 ◽  
Author(s):  
Zoran Ren ◽  
Matej Vesenjak ◽  
Andreas Öchsner
Keyword(s):  
Relative Density ◽  
Impact Loading ◽  
Cellular Structure ◽  
Computational Models ◽  
Computational Study ◽  
Base Material ◽  
Cellular Structures ◽  
Open Cell ◽  
Closed Cell ◽  
Regular Open

New multiphysical computational models for simulation of regular open and closed-cell cellular structures behaviour under compressive impact loading are presented. The behaviour of cellular structures with fluid fillers under uniaxial impact loading and large deformations has been analyzed with the explicit nonlinear finite element code LS-DYNA. The behaviour of closed-cell cellular structure has been evaluated with the use of the representative volume element, where the influence of residual gas inside the closed pores has been studied. Open-cell cellular structure was modelled as a whole to properly account for considered fluid flow through the cells, which significantly influences macroscopic behaviour of cellular structure. The fluid has been modelled by applying a Smoothed Particle Hydrodynamics (SPH) method. Computational simulations showed that the base material has the highest influence on the behaviour of cellular structures under impact conditions. The increase of the relative density and strain rate results in increase of the cellular structure stiffness. Parametrical numerical simulations have also confirmed that filler influences the macroscopic behaviour of the cellular structures which depends on the loading type and the size of the cellular structure. In open-cell cellular structures with higher filler viscosity and higher relative density, increased impact energy absorption has been observed.

scholarly journals Correlation Between the Structure and Compressive Property of PMMA Microcellular Foams Fabricated by Supercritical CO2 Foaming Method

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 315 ◽  
Author(s):  
Ruizhi Zhang ◽  
Ju Chen ◽  
Yuxuan Zhu ◽  
Jian Zhang ◽  
Guoqiang Luo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Size ◽  
Supercritical Co2 ◽  
Cellular Structure ◽  
Experimental Testing ◽  
Element Model ◽  
Cellular Structures ◽  
Compressive Property ◽  
Compressive Properties ◽  
Microcellular Foams

In this study, we fabricated poly (methyl methacrylate) (PMMA) microcellular foams featuring tunable cellular structures and porosity, through adjusting the supercritical CO2 foaming conditions. Experimental testing and finite element model (FEM) simulations were conducted to systematically elucidate the influence of the foaming parameters and structure on compressive properties of the foam. The correlation between the cellular structure and mechanical properties was acquired by separating the effects of the cell size and foam porosity. It was found that cell size reduction contributes to improved mechanical properties, which can be attributed to the dispersion of stress and decreasing stress concentration.

High-performance polyvinylpyrrolidone capped copper coatings via ultrasonic-assisted supercritical-CO2 electrodeposition: Electrochemical evaluation

2021 ◽  
Vol 409 ◽  
pp. 126926
Author(s):  
Sabarison Pandiyarajan ◽  
Po-Ju Hsiao ◽  
Ai-Ho Liao ◽  
Muthusankar Ganesan ◽  
Sheng-Tung Huang ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
High Performance ◽  
Copper Coatings ◽  
Ultrasonic Assisted ◽  
Electrochemical Evaluation

High-performance anti-corrosion behavior of graphene oxide decorated nickel coating by novel ultrasonic-assisted supercritical-CO2 electrodeposition approach

2021 ◽  
Vol 387 ◽  
pp. 138543
Author(s):  
Sabarison Pandiyarajan ◽  
Zhao Chen Liu ◽  
Ai-Ho Liao ◽  
Muthusankar Ganesan ◽  
Sheng-Tung Huang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Corrosion Behavior ◽  
Supercritical Co2 ◽  
High Performance ◽  
Nickel Coating ◽  
Ultrasonic Assisted

scholarly journals Viscoelastic Properties of Cell Structures Manufactured Using a Photo-Curable Additive Technology—PJM

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1895
Author(s):  
Tomasz Kozior ◽  
Czesław Kundera
Keyword(s):  
Viscoelastic Properties ◽  
Cellular Structure ◽  
Material Selection ◽  
Cellular Structures ◽  
Test Results ◽  
Additive Technology ◽  
Polymer Resin ◽  
Cell Structures ◽  
Relaxation Curves ◽  
The Impact

This research paper reviews the test results involving viscoelastic properties of cellular structure models made with the PolyJet Matrix—PJM additive technology. The designed test specimens were of complex cellular structure and made of three various photo-curable polymer resin types. Materials were selected taking into account the so-called “soft” and “tough” material groups. Compressive stress relaxation tests were conducted in accordance with the recommendations of standard ISO 3384, and the impact of the geometric structure shape and material selection on viscoelastic properties, as well as the most favorable geometric variants of the tested cellular structure models were determined. Mathematica and Origin software was used to conduct a statistical analysis of the test results and determine five-parameter functions approximating relaxation curves. The most favorable rheological was adopted and its mean parameters determined, which enables to match both printed model materials and their geometry in the future, to make a component with a specific rheological response. Furthermore, the test results indicated that there was a possibility of modelling cellular structures within the PJM technology, using support material as well.

Properties of Random PSF/PES Copolymers as High-Performance Polymers

2011 ◽  
Vol 217-218 ◽  
pp. 1606-1610
Author(s):  
Dong Jiang ◽  
Xiao Ran Zhang ◽  
Yan Mei Ma ◽  
Cheng You Ma
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Glass Transition ◽  
High Performance ◽  
Molar Ratio ◽  
Transition Temperatures ◽  
Elongation At Break ◽  
Glass Transition Temperatures ◽  
High Performance Polymers ◽  
Diphenyl Sulfone

A series of random polysulfone/polyethersulfone (PSF/PES) copolymers were synthesized by the polycondensation of 4, 4'-isopropylidendiphenol, 4, 4΄-dihyolroxy diphenyl sulfone and 4, 4'-dichlorodiphenyl sulfone in the presence of K2CO3. We obtained a series of copolymers by changing the molar ratio of 4, 4΄-dihyolroxy diphenyl sulfone and 4, 4'-isopropylidendiphenol (it was marked as the ratio of S:A). The copolymers have the similar solubility with polyethersulfone. They also have high glass transition temperatures (Tg: 199°C~229°C) and 5% weight loss temperatures (4, 4'-isopropylidendiphenol: 4, 4΄-dihyolroxy diphenyl sulfone=1:1, Td5=497°C). At the same time the elongation at break is much higher than that of PES, while the tensile strength is a little lower than that of PES.

scholarly journals Preparation and properties of silicone rubber materials with foam/solid alternating multilayered structures

2021 ◽  
Author(s):  
Wenhuan Zhang ◽  
Zhaoping Deng ◽  
Hongwei Yuan ◽  
Shikai Luo ◽  
Huayin Wen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silicone Rubber ◽  
Cellular Structure ◽  
Cellular Structures ◽  
Compressive Property ◽  
Solid Layer ◽  
Multilayered Structures ◽  
Element Analysis ◽  
Morphology And Mechanical Properties

AbstractIn this paper, silicone rubber materials with foam/solid alternating multilayered structures were successfully constructed by combining the two methods of multilayered hot-pressing and supercritical carbon dioxide (SCCO2) foaming. The cellular morphology and mechanical properties of the foam/solid alternating multilayered silicone rubber materials were systematically studied. The results show that the growth of the cell was restrained by the solid layer, resulting in a decrease in the cell size. In addition, the introduction of the solid layer effectively improved the mechanical properties of the microcellular silicone rubber foam. The tensile strength and compressive strength of the foam/solid alternating multilayered silicone rubber materials reached 5.39 and 1.08 MPa, which are 46.1% and 237.5% of the pure silicone rubber foam, respectively. Finite element analysis (FEA) was applied and the results indicate that the strength and proportion of the solid layer played important roles in the tensile strength of the foam/solid alternating multilayered silicone rubber materials. Moreover, the small cellular structures in silicone rubber foam can provided a high supporting counterforce during compression, meaning that the microcellular structure of silicone rubber foam improved the compressive property compared to that for the large cellular structure of silicone rubber foam.

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