Gas permeability and mechanical properties of PDMS mixed with PMPS nanofibers produced by electrospinning

2012 ◽  
Vol 1410 ◽  
Author(s):  
Atsushi Nakano ◽  
Norihisa Miki ◽  
Koichi Hishida ◽  
Atsushi Hotta
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
Gas Permeability ◽  
Phenyl Group ◽  
Pdms Membrane ◽  
Solubility Parameters ◽  
Permeability Test ◽  
Enhancement Mechanism ◽  
Siloxane Polymer ◽  
Different Diameters

ABSTRACTPolymethylphenylsilicone (PMPS), a siloxane polymer with a phenyl group, was first successfully electrospun to fabricate different diameters of silicone fibers ranging from 500 nm to 10 μm by considering solubility parameters of 12 different solvents. The resulting PMPS fibers were mixed with polydimethylsiloxane (PDMS) by retaining their original nanofiber structures to produce a polysiloxane-based nanofibrous composite. As for the mechanical properties, the PMPS/PDMS composite presented higher Young’s modulus and higher fracture strain than pure PDMS. The gas permeability test revealed that the PMPS/PDMS composite exhibited higher CO2 permeability than the pure PDMS membrane. Moreover, CO2 permeability gradually increased by raising the compounding ratio of PMPS-fibers in the PMPS/PDMS composite and by decreasing the diameter of PMPS-fibers. The enhancement mechanism observed in both mechanical properties and CO2 permeability was discussed from the viewpoint of the interface between PMPS and PDMS along with the nanofiber network structures.

Assessing the effect of FDM processing parameters on mechanical properties of PLA parts using Taguchi method

2021 ◽  
pp. 089270572110530
Author(s):  
Nagarjuna Maguluri ◽  
Gamini Suresh ◽  
K Venkata Rao
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Fused Deposition Modeling ◽  
Fracture Strain ◽  
Processing Parameters ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Nozzle Temperature ◽  
Experimental Runs ◽  
Printing Speed

Fused deposition modeling (FDM) is a fast-expanding additive manufacturing technique for fabricating various polymer components in engineering and medical applications. The mechanical properties of components printed with the FDM method are influenced by several process parameters. In the current work, the influence of nozzle temperature, infill density, and printing speed on the tensile properties of specimens printed using polylactic acid (PLA) filament was investigated. With an objective to achieve better tensile properties including elastic modulus, tensile strength, and fracture strain; Taguchi L8 array has been used for framing experimental runs, and eight experiments were conducted. The results demonstrate that the nozzle temperature significantly influences the tensile properties of the FDM printed PLA products followed by infill density. The optimum processing parameters were determined for the FDM printed PLA material at a nozzle temperature of 220°C, infill density of 100%, and printing speed of 20 mm/s.

scholarly journals Microstructure and mechanical properties of slowly cooled Cu47.5Zr47.5Al5

2007 ◽  
Vol 22 (2) ◽  
pp. 326-333 ◽  
Author(s):  
J. Das ◽  
S. Pauly ◽  
C. Duhamel ◽  
B.C. Wei ◽  
J. Eckert
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
Volume Fraction ◽  
Spherical Shape ◽  
High Yield ◽  
High Yield Strength ◽  
Scanning Calorimetry ◽  
Arc Melting ◽  
Martensite Matrix

Cu47.5Zr47.5Al5 was prepared by arc melting and solidified in situ by suction casting into 2–5-mm-diameter rods under various cooling rates (200–2000 K/s). The microstructure was investigated along the length of the rods by electron microscopy, differential scanning calorimetry and mechanical properties were investigated under compression. The microstructure of differently prepared specimens consists of macroscopic spherical shape chemically inhomogeneous regions together with a low volume fraction of randomly distributed CuZr B2 phase embedded in a 2–7 nm size clustered “glassy-martensite” matrix. The as-cast specimens show high yield strength (1721 MPa), pronounced work-hardening behavior up to 2116 MPa and large fracture strain up to 12.1–15.1%. The fracture strain decreases with increasing casting diameter. The presence of chemical inhomogenities and nanoscale “glassy-martensite” features are beneficial for improving the inherent ductility of the metallic glass.

scholarly journals Simultaneous Enhancement of Strength and Toughness of PLA Induced by Miscibility Variation with PVA

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1178 ◽  
Author(s):  
Yanping Liu ◽  
Hanghang Wei ◽  
Zhen Wang ◽  
Qian Li ◽  
Nan Tian
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Fracture Strain ◽  
Electrospun Fiber ◽  
Structural Evolution ◽  
Amorphous Structure ◽  
Poly Lactic Acid ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Strength And Toughness

The mechanical properties of poly (lactic acid) (PLA) nanofibers with 0%, 5%, 10%, and 20% (w/w) poly (vinyl alcohol) (PVA) were investigated at the macro- and microscale. The macro-mechanical properties for the fiber membrane revealed that both the modulus and fracture strain could be improved by 100% and 70%, respectively, with a PVA content of 5%. The variation in modulus and fracture strain versus the diameter of a single electrospun fiber presented two opposite trends, while simultaneous enhancement was observed when the content of PVA was 5% and 10%. With a diameter of 1 μm, the strength and toughness of the L95V5 and L90V10 fibers were enhanced to over 3 and 2 times that of pure PLA, respectively. The structural evolution of electrospun nanofiber was analyzed by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Although PLA and PVA were still miscible in the concentration range used, the latter could crystallize independently after electrospinning. According to the crystallization behavior of the nanofibers, a double network formed by PLA and PVA—one microcrystal/ordered structure and one amorphous structure—is proposed to contribute to the simultaneous enhancement of strength and toughness, which provides a promising method for preparing biodegradable material with high performance.

scholarly journals The Role of the Diameter of the Titanium, Fiber and Zirconium Posts

2018 ◽  
Vol 11 ◽  
pp. 2241-2249
Author(s):  
Vesna Jurukovska Shotarovska ◽  
Biljana Kapusevska ◽  
Nikola Dereban
Keyword(s):  
Mechanical Properties ◽  
Fracture Strength ◽  
Software System ◽  
Fracture Force ◽  
Fiber Posts ◽  
Special Software ◽  
Different Types ◽  
Different Diameters

The goal is to compare the strength of a fracture among titanium, fiber and zirconium posts. We have formed three group: titanium, fiber and zirconium,, and each group has 20 samples with 3 different diameters. The posts were tested using "Shimadzu Univerzal Testing Mashine" at the same distance, and the force was applied to all at the same place. The fracture strength was registered on a special software system. Between posts with the same diameter (1.2 mm) the greatest average fracture force has titanium posts 161.69 N (± 0.07), followed by fiber posts 45.38N (± 0, 01) and zirconium posts 34.81N (± 0.01). between the subgroups of the same  diameter (1.35mm), the greatest average fracture strength has the titanium posts 165.26N (± 0.01), followed by the fiber posts 71.57N (± 0.01) and zirconium posts 46.53N (± 0.004). between the subgroups of the same diameter (1.5 mm) the largest average fracture force has titanium posts 202.42N (± 0.01), followed by fiber posts 73.67N (± 0.004) and zirconium posts 67.15N (± 0.004). The diameter of the different types of posts gives different mechanical properties that affect differently the resistance of the fracture strength.

scholarly journals Mechanical properties of boron nitride sheet with randomly distributed vacancy defects

2019 ◽  
Vol 8 (1) ◽  
pp. 210-217 ◽  
Author(s):  
Yingjing Liang ◽  
Hongfa Qin ◽  
Jianzhang Huang ◽  
Sha Huan ◽  
David Hui
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Performance Optimization ◽  
Fracture Strain ◽  
Mechanical Performance ◽  
Hexagonal Boron Nitride ◽  
Stable Configuration ◽  
Vacancy Defects ◽  
And Performance ◽  
Dynamics Simulations

Abstract Defects and temperature effects on the mechanical properties of hexagonal boron nitride sheet (h-BN) containing randomly distributed defects are investigated by molecular dynamics simulations and the reasons of the results are discussed. Results show that defect deteriorate the mechanical performance of BNNS. The mechanical properties are reduced by increasing percentage of vacancy defects including fracture strength, fracture strain and Young’s modulus. Simulations also indicate that the mechanical properties decrease with the temperature increasing. Moreover, defects affect the stable configuration at high temperature. With the percentage of defect increases the nanostructures become more and more unstable. Positions of the defect influent the mechanical properties. The higher the temperature and the percentage of defect are, the stronger the position of the randomly distributed defect affects the mechanical properties. The study provides a theoretical basis for the preparation and performance optimization of BNNSs.

scholarly journals Novolac/Phenol-Containing Phthalonitrile Blends: Curing Characteristics and Composite Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 126 ◽  
Author(s):  
Hanqi Zhang ◽  
Bing Wang ◽  
Yanna Wang ◽  
Heng Zhou
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
Mechanical Test ◽  
Gelation Time ◽  
Mechanical Analysis ◽  
Curing Temperature ◽  
Hydroxyl Group ◽  
Rheological Analysis ◽  
Curing Characteristics ◽  
Ft Ir

The phenol-containing phthalonitrile resin is a kind of self-curing phthalonitrile resin with high-temperature resistance and excellent properties. However, the onefold phthalonitrile resin is unattainable to cured completely, and the brittleness of the cured product is non-negligible. This paper focuses on solving the above problems by blending novolac resin into phenol-containing phthalonitrile. Under the action of abundant hydroxyl group, the initial curing temperature and gelation time at 170 °C decrease by 88 °C and 2820 s, respectively, monitored by DSC and rheological analysis. FT-IR spectra of copolymers showed that the addition of novolac increased the conversion rate of nitrile. When the novolac mass fraction is 10%, the peak of nitrile group disappears, which means the complete reaction. The mechanical test of blends composites shows that the maximum fracture strain of 10 wt% novolac addition is 122% higher than those of neat phthalonitrile composites on account of the introduction of flexible novolac chain segments. The mechanical properties are sensitive to elevated post-cured temperature; this is consistent with the result of morphological investigation using SEM. Finally, the dynamic mechanical analysis indicated that the glass transition temperature heightened with the increase of novolac content and post-curing temperature.

scholarly journals Determination of mechanical properties of soil under laboratory conditions

2014 ◽  
Vol 60 (Special Issue) ◽  
pp. S66-S69 ◽  
Author(s):  
V. Malý ◽  
M. Kučera
Keyword(s):  
Mechanical Properties ◽  
Penetration Depth ◽  
Measuring Device ◽  
Laboratory Conditions ◽  
Measuring Network ◽  
Set Up ◽  
Different Diameters ◽  
Different Levels ◽  
Properties Of Soil

This paper presents the mechanical properties of soil. In order to determine the properties of soil under laboratory conditions, a special measuring device was constructed, viz. a bevameter. Two types of soil with different levels of moisture were examined and their mechanical properties were determined. Measurements were taken of non-compressed soil. A measuring network was set up, consisting of measuring and recording devices. In the course of measuring, the force and penetration depth of the pressing plate were recorded simultaneously. Three different diameters of pressing plate were used, namely 38, 50 and 70 mm. The pressure on the contact area was calculated after completion of the measurements, and the relationships between pressure and penetration depth were presented graphically.

Ageing Effect on Mechanical Properties of Machined Nanostructures

2013 ◽  
Vol 683 ◽  
pp. 145-149
Author(s):  
Xing Lei Hu ◽  
Ya Zhou Sun ◽  
Ying Chun Liang ◽  
Jia Xuan Chen
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Md Simulation ◽  
Fracture Strain ◽  
Machining Process ◽  
Ageing Process ◽  
Yield Strain ◽  
Before And After ◽  
Mc Simulation

Monte Carlo (MC) method and molecular dynamics (MD) are combined to analyze the influence of ageing on mechanical properties of machined nanostructures. Single crystal copper workpiece is first cut in MD simulation, and then the machined workpiece is used in MC simulation of ageing process, finally the tensile mechanical properties of machined nanostructures before and after ageing are investigated by MD simulation. The results show that machining process and ageing have obvious influence of tensile mechanical properties. After machining, the yield strength, yield strain, fracture strain and elastic modulus reduce by 36.02%, 28.86%, 20.79% and 7.16% respectively. However, the yield strength, yield strain and elastic modulus increase by 4.84%, 1.41% and 1.02% respectively, fracture strain reduce by 24.53% after ageing process. To research the ageing processes of machined nanostructures by MC simulation is both practical and meaningful.

Effects of Pore Morphology on the Fabrication and Mechanical Properties of Porous Si3N4 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 1231-1236
Author(s):  
Jian Feng Yang ◽  
Ji Qiang Gao ◽  
Guo Jun Zhang ◽  
Ichiro Hayashi ◽  
Tatsuki Ohji
Keyword(s):  
Mechanical Properties ◽  
Gas Permeability ◽  
Slip Casting ◽  
Porous Ceramics ◽  
Pore Morphology ◽  
Porous Si ◽  
Die Pressing ◽  
Porous Si3n4 ◽  
Si3n4 Ceramics ◽  
Porous Si3n4 Ceramics

Porous Si3N4 ceramics with different pore morphology have been fabricated, utilizing either organic whiskers or starch as the fugitive agents, through slip-casting and die-pressing technique, respectively. The obtained porous ceramics have rod shaped or equiaxial pore morphology, originated from there two kinds of pore forming agents. The mechanical properties were investigated. The strength decreased considerably when small amount of whiskers were added, however, further increase in the whisker content only cause a moderate decrease of the strength. Gas permeability were measured for the samples with high whisker content of 60 vol% (corresponding to porosity of about 45% in the sintered bodies), and was compared with the counterpart contained the same porosity in which pores were equiaxial. The flexural strength of the samples with these two types of fugitive particles was almost the same, but the permeability of samples with rod-shaped pores were much higher than that with equiaxial pores, which can be understood in terms of a short pass model.

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