Effects of ionic liquid types on the tribological, mechanical, and thermal properties of ionic liquid modified graphene/polyimide shape memory composites

2021 ◽  
pp. 095400832199676
Author(s):  
Yuting Ouyang ◽  
Qiu Zhang ◽  
Xiukun Liu ◽  
Ruan Hong ◽  
Xu Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Composite Materials ◽  
Shape Memory ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Graphene Nanosheets ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Modified Graphene

Different ionic liquid modified graphene nanosheets (IG) were induced into polyimide (PI) to improve the tribological, thermal, and mechanical properties of shape memory IG/PI composites. The results demonstrated that when using 1-aminoethyl-3-methylimidazole bromide to modify graphene nanosheets (IG-1), the laser-driven shape recovery rate of IG-1/PI composites (IGPI-1) reached 73.02%, which was 49.36% higher than that of pure PI. In addition, the IGPI-1 composite materials reached the maximum shape recovery rate within 15 s. Additionally, under dry sliding, the addition of IG can significantly improve the tribological properties of composite materials. IGPI-1 exhibited the best self-lubricating properties. Compared with pure PI, the friction coefficient (0.19) and wear rate (2.62 × 10–5) mm3/Nm) were reduced by 44.1% and 24.2%, respectively, and the T10% of IGPI-1 increased by 32.2°C. The Tg of IGPI-1 reached 256.5°C, which was 8.4°C higher than that of pure PI. In addition, the tensile strength and modulus of IGPI-1 reached 82.3 MPa and 1.18 GPa, which were significantly increased by 33.6% and 29.8%, respectively, compared with pure PI. We hope that this work will be helpful for the preparation of shape memory materials with excellent tribological, thermal, and mechanical properties.

Synthesis and Characterization of a Bio-Compatible Shape Memory Polymer Blend for Biomedical and Clinical Applications

2014 ◽  
Author(s):  
Janice J. Song ◽  
Jennifer Kowalski ◽  
Hani E. Naguib
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shape Memory ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Clinical Applications ◽  
Poly Lactic Acid ◽  
Shape Memory Properties ◽  
Shape Fixity ◽  
Recovery Temperature

Shape memory polymers (SMP) are a class of stimuli-responsive materials that are able to respond to external stimulus such as heat by altering their shape. Bio-compatible SMPs have a number of advantages over existing SMP materials and are being studied extensively for biomedical and clinical applications. Polymer blending has proved to be an effective method to improve the mechanical properties of polymers (such as tensile strength and toughness) as well as shape memory properties. In this study, we investigate the effect of blending two bio compatible polymers, thermoplastic polyurethane (TPU), a polymer with a high toughness and percent elongation, and poly-lactic acid (PLA), a stiff and strong polymer. The thermal, mechanical and thermo-mechanical (shape memory) properties of TPU/PLA blends were characterized in the following weight percent compositions: 80/20, 65/35, and 50/50 TPU/PLA. The TPU/PLA SMP blending was achieved with melt-blending and the tensile samples were fabricated with compression molding. The mechanical properties of each blend were studied at three different temperatures. The following thermo-mechanical (or shape memory) properties were also studied at each temperature: the shape fixity rate (Rf), shape recovery rate (Rr) and the effect of recovery temperature on the shape memory behavior. The microstructure of the polymer blends were investigated with an environmental scanning electron microscope (SEM). The results showed that the glass transition temperatures of the blends were similar to pure PLA. The toughness of the SMP blend increased with increasing TPU concentration and the tensile strength of the blend increased with PLA composition. The shape fixity rate of the TPU/PLA blend increased with increasing TPU content and the shape recovery rate increased with increasing deformation and recovery temperature. The various TPU/PLA SMP blends characterized in this study have the potential to be developed further for specific biomedical and clinical applications.

Pseudoelasticity of Cu-13.8Al-Ni Alloys Containing V and Nb

2008 ◽  
Vol 59 ◽  
pp. 101-107 ◽  
Author(s):  
Rodinei Medeiros Gomes ◽  
Ana Cris R. Veloso ◽  
V.T.L. Buono ◽  
Severino Jackson Guedes de Lima ◽  
Tadeu Antonio de Azevedo Melo
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Shape Recovery ◽  
Cold Water ◽  
Low Cost ◽  
Tensile Tests ◽  
Grain Refiner ◽  
Good Shape ◽  
Potential Applications ◽  
Superelastic Behavior

Polycrystalline copper-based shape memory alloys have been of particular interest in relation to Ni-Ti because of their low cost and good shape memory effect. Nevertheless the absence of a pronounced pseudoelasticity effect restricts the number of potential applications. In this work, the influence of Nb and V on the microstructure and the mechanical properties was investigated. Samples of Cu-13.8 Al-Ni containing V and Nb alloy were prepared by induction and solution treated at 850°C and then further quenched into cold water. The addition of Nb and V promotes the formation of precipitates which act as grain refiner and subsequently improve the mechanical properties. The tensile tests were performed at temperatures slightly inferior to Mf and superior to Af, to investigate the shape recovery and pseudoelasticity, respectively. Based on the analyses of the Cu-13,8Al-2Ni-1Nb (wt%) alloy was detected rupture strains greater than 14%, besides observation of the superelasticity of these alloys and quantification of this property by means of cycling, from 0 to strains between 1 and 7%. The studies performed on alloy Cu-13.8Al- 3,5Ni-1V (wt%) made it possible to determine rupture strains in the order of 3% and its superelastic behavior through cycling for deformations between 1 and 3%.

Mechanical and thermal properties of PP/compatibilized PP/acid treated SWNTs nanocomposites: Effect of different acid treatment times

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Morteza Ghorbanzadeh Ahangari ◽  
Abdolhosein Fereidoon ◽  
Seyfolah Saedodin
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Acid Treatment ◽  
Treatment Process ◽  
Tensile Tests ◽  
Acid Mixture ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Maleated Polypropylene ◽  
Carboxylic Groups

AbstractIn the present work, the effect of different acid treatment times of singlewalled carbon nanotubes (SWNTs) on the mechanical and thermal properties of polypropylene (PP)/maleated polypropylene (PP-g-MA) nanocomposites was investigated. The acid treatment process was based on a mixture of concentrated sulphuric and nitric acids. The SWNTs were treated with the acid mixture for 1, 3, and 6 h. FTIR, Raman spectroscopy and TEM revealed the values of carboxylic groups, graphitization and morphology of acid treated SWNTs, respectively. The thermal and mechanical properties and the morphology of nanocomposites were investigated by tensile tests, DMTA, DSC, and SEM.

scholarly journals Nanoscale Mechanical Properties of Nanoindented Ni48.8Mn27.2Ga24 Ferromagnetic Shape Memory Thin Film

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Xiaofei Fu ◽  
Chao Liu ◽  
Xili Lu ◽  
Xianli Li ◽  
Jingwei Lv ◽  
...  
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Martensitic Transformation ◽  
Magnetron Sputtering ◽  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Recovery Ratio ◽  
Dc Magnetron Sputtering ◽  
Ferromagnetic Shape Memory

The structure and nanoscale mechanical properties of Ni48.8Mn27.2Ga24 thin film fabricated by DC magnetron sputtering are investigated systematically. The thin film has the austenite state at room temperature with the L21 Hesuler structure. During nanoindentation, stress-induced martensitic transformation occurs on the nanoscale for the film annealed at 823 K for 1 hour and the shape recovery ratio is up to 85.3%. The associated mechanism is discussed.

scholarly journals Structure, Mechanical and Thermal Properties of Polyphenylene Sulfide and Polysulfone Impregnated Carbon Fiber Composites

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 684 ◽  
Author(s):  
Chukov ◽  
Nematulloev ◽  
Zadorozhnyy ◽  
Tcherdyntsev ◽  
Stepashkin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Fiber Composites ◽  
Chemical Oxidation ◽  
Interfacial Interaction ◽  
Polyphenylene Sulfide ◽  
Carbon Fiber Composites ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties

The paper studies new high-temperature thermoplastic impregnated unidirectional carbon fiber composites. The research focuses on the effect of thermal and chemical oxidation of the carbon fibers surface on the interfacial interaction between fibers and polysulfone and polyphenylene sulfide as well as thermal and mechanical properties of the composites. The research reveals the interaction between carbon fibers and the polymer matrix depend both on the type of surface treatment and nature of the polymer. The chemical oxidation of carbon fibers results in good interfacial interaction, and the best mechanical properties were observed for tows impregnated with polyphenylene sulfide.

Mechanical and Thermal Properties of Ternary System Based on Starch-Grafted-Polyethylene/High Density Polyethylene/Halloysite Nanocomposites

2019 ◽  
Vol 800 ◽  
pp. 210-215
Author(s):  
Walid Fermas ◽  
Mustapha Kaci ◽  
Remo Merijs Meri ◽  
Janis Zicans
Keyword(s):  
Mechanical Properties ◽  
High Density Polyethylene ◽  
Chemical Structure ◽  
Filler Content ◽  
Halloysite Nanotubes ◽  
High Density ◽  
Flexural Properties ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Content Ratio

In this paper, the effect of unmodified halloysite nanotubes (HNTs) content on the chemical structure and the thermal and mechanical properties of blends based on starch-grafted-polyethylene (SgP) and high density polyethylene (HDPE) (70/30 w/w) nanocomposites was investigated at various filler content ratios, i.e. 1.5, 3 and 5 wt.%. The study showed the occurrence of chemical interactions between the polymer matrix and HNTs through OH bonding. Further, the addition of HNTs to the polymer blend led to an increase in the crystallization temperature of the nanocomposite samples, in particular at higher filler contents i.e. 3 and 5 wt.%, while the melting temperature remained almost unchanged. Tensile and flexural properties of the nanocomposite samples were however improved compared to the virgin blend with respect to the HNTs content ratio.

Identification and enhancement of the thermal and mechanical properties of two types of plasters successively derived from gypsum: from the Safi basin and the High Atlas of Marrakech, Morocco

2020 ◽  
Author(s):  
imane baba ◽  
Mounsif Ibnoussina ◽  
Omar Witam
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Mechanical Strength ◽  
Setting Time ◽  
Density Measurement ◽  
Raw Material ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
X Ray Diffraction ◽  
High Atlas

<p>Over the past few decades, the construction industry has focused on sustainable, environmentally friendly and easily recyclable materials. The objective of this work is to characterize and enhance the thermal conductivity, mechanical strength and setting time of a composite material based on plaster and lime. This material is designed for use in plasters.</p><p>Two types of gypsum are studied, the first one belongs to the Safi basin, the second one characterizes the High Atlas of Marrakech and precisely Douar Tafza. Geologically speaking, the two sites have many similarities. They are characterized by a Meso-Cenozoic age coverage covering a deformed Paleozoic age basement.</p><p>The characterization of the plaster's raw material, gypsum, was necessary to determine its physical and geotechnical properties, mineralogy, thermal behaviour and microscopic structure. Several analyses have been developed such as: pycnometer density measurement, X-ray diffraction, infrared spectroscopy and scanning electron microscopy.</p><p>We made samples, of standardized dimensions, of two mixtures based on the two types of plaster reinforced by the addition of two types of lime from different localities. The latter are from Marrakech and the Agadir region. The water/plaster mass ratio was set at 0.75 and the addition of lime was achieved by increasing its percentage in slices by 12.5% and up to 50%.</p><p>The reinforcement of plaster with lime has enhanced its thermal and mechanical properties and setting time. The measurements show that the addition of lime has reduced the thermal conductivity and increased the mechanical strength of both types of plaster. In addition, following the addition of lime, the setting time has decreased and the basicity of the material has increased. Noting that the intrinsic properties of the raw material influence the mechanical and thermal properties of the material.</p><p><strong>Keywords:</strong>   plaster, enhancement, properties, mechanical, thermal, Morocco</p>

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