scholarly journals Curing Temperature Effects on the Tensile Properties and Hardness of γ−Fe2O3 Reinforced PDMS Nanocomposites

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yvonne Konku-Asase ◽  
Abu Yaya ◽  
Kwabena Kan-Dapaah
Keyword(s):  
Mechanical Properties ◽  
Quantitative Data ◽  
Biomedical Applications ◽  
Processing Parameters ◽  
Curing Temperature ◽  
Background Information ◽  
Chemical Bonds ◽  
Research Groups ◽  
Preparation Conditions ◽  
Selection Of

The mechanical properties of plain polydimethylsiloxane (PDMS) and its nanocomposites have been exploited for various theranostic biomedical applications. Although several research groups have investigated the effects of preparation conditions—especially curing temperature and time—on bulk mechanical properties of plain PDMS, there are no reported similar studies for its nanocomposites. In this study, mechanical properties of PDMS reinforced by different volume fractions (ϕmnp=0–2 vol. %) of γ-Fe2O3 nanoparticles (NPs) were investigated and quantitative data presented for different curing temperatures (25, 100, and 150°C). To a large extent, γ-Fe2O3 NPs were uniformly dispersed in the PDMS matrix with no primary chemical bonds formed. For the temperatures tested, the data showed an increase for Young’s modulus (E) of about 170% (1.36–3.71 MPa) and a decrease of the ultimate tensile strength (UTS) of about 65% (6.48–2.93 MPa) with increasing concentration of the NPs. Furthermore, hardness (Shore A) (H) increased with curing temperature but decreased with concentration. Based on the findings, we conclude that the linear relationship between the calculated mechanical properties (E, UTS, H) and small ϕmnp is independent of the curing temperature. The experimental data provide useful background information for the selection of processing parameters for PDMS nanocomposite fabrication.

scholarly journals 3D-printable zwitterionic nano-composite hydrogel system for biomedical applications

2020 ◽  
Vol 11 ◽  
pp. 204173142096729
Author(s):  
Nathalie Sällström ◽  
Andrew Capel ◽  
Mark P Lewis ◽  
Daniel S Engstrøm ◽  
Simon Martin
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Culture Medium ◽  
Careful Selection ◽  
Nano Composite ◽  
Significant Difference ◽  
Nano Clay ◽  
Hydrogel Surface ◽  
Selection Of ◽  
Hydrogel System

Herein, the cytotoxicity of a novel zwitterionic sulfobetaine hydrogel system with a nano-clay crosslinker has been investigated. We demonstrate that careful selection of the composition of the system (monomer to Laponite content) allows the material to be formed into controlled shapes using an extrusion based additive manufacturing technique with the ability to tune the mechanical properties of the product. Moreover, the printed structures can support their own weight without requiring curing during printing which enables the use of a printing-then-curing approach. Cell culture experiments were conducted to evaluate the neural cytotoxicity of the developed hydrogel system. Cytotoxicity evaluations were conducted on three different conditions; a control condition, an indirect condition (where the culture medium used had been in contact with the hydrogel to investigate leaching) and a direct condition (cells growing directly on the hydrogel). The result showed no significant difference in cell viability between the different conditions and cells were also found to be growing on the hydrogel surface with extended neurites present.

Mechanical Properties of Coil Coating Evaluated with Dynamic Mechanical Analysis in Daul Cantilever

2007 ◽  
Vol 353-358 ◽  
pp. 1729-1732 ◽  
Author(s):  
Lei Chen ◽  
Hong Liang Pan
Keyword(s):  
Mechanical Properties ◽  
Dynamic Mechanical Analysis ◽  
Loss Modulus ◽  
Paint Layer ◽  
Mechanical Analysis ◽  
Curing Temperature ◽  
Mode Analysis ◽  
Dynamic Mechanical ◽  
Preparation Conditions ◽  
Coil Coating

The storage modulus, loss modulus, loss tangent (tanδ), stress and strain have been determined for painted steel specimens by dynamic mechanical analysis (DMA) operated in Dual Cantilever mode. Analysis of the composite system enabled the elastic modulus of the paint layer to be calculated and the result can be useful to analyze the mechanical properties of the coil coating. The calculation was found to be very sensitive to the geometry (especially thickness of the substrate and coating) and properties of the substrate and coating, leading to considerable variability in the calculated coating modulus. The DMA method was successful in detecting the glass transition temperature (Tg) as a peak in the tanδ curve. The value of Tg is sensitive to the preparation conditions (e.g. curing temperature) and composition of the paint. The results show that DMA in Dual Cantilever can be useful as a characterization tool for painted steel.

Nano-Filled Polymer Composites for Biomedical Applications

2008 ◽  
Author(s):  
Maximiano V. Ramos ◽  
Armstrong Frederick ◽  
Ahmed M. Al-Jumaily
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Polymer Nanocomposites ◽  
Biomedical Applications ◽  
Mixing Time ◽  
Correct Choice ◽  
Processing Parameters ◽  
Experimental Procedure ◽  
Filled Polymer

Polymer nanocomposites offer various functional advantages required for several biomedical applications. For example, polymer nanocomposites are biocompatible, biodegradable, and can be engineered to have mechanical properties suitable for specific applications. The key to the use of polymer nanocomposites for different applications is the correct choice of matrix polymer chemistry, filler type, and matrix-filler interaction. This paper discusses the results of a study in the processing and characterization of nono-filled polymer composites and focuses on the improvement of its properties for potential biomedical applications. The experimental procedure for the preparation of nano-filled polymer composite by ultrasonic mixing is described. Different types of nanofillers and polymer matrix are studied. Effects of processing parameters such as percent loading of fillers, mixing time on the mechanical properties of the composites are discussed. Preliminary results indicate improvement in shear and flexural properties, tensile and compressive properties, were observed in the prepared composites for some processing conditions.

scholarly journals Binder Saturation, Layer Thickness, Drying Time and Their Effects on Dimensional Tolerance and Density of Cobalt Chrome- Tricalcium Phosphate Biocomposite

2021 ◽  
Author(s):  
Ruprecht John ◽  
Kuldeep Agarwal ◽  
Shaheen Ahmed
Keyword(s):  
Mechanical Properties ◽  
Layer Thickness ◽  
Tricalcium Phosphate ◽  
Biomedical Applications ◽  
Processing Parameters ◽  
Drying Time ◽  
Dimensional Tolerance ◽  
Binder Saturation ◽  
Binder Jetting ◽  
Cobalt Chrome

Traditional metals such as stainless steel, titanium and cobalt chrome are used in biomedical applications (implants, scaffolds etc.) but suffer from issues such as osseointegration and compatibility with existing bone. One way to improve traditional biomaterials is to incorporate ceramics with these metals so that their mechanical properties can be similar to cortical bones. Tricalcium phosphate is such a ceramic with properties so that it can be used in human body. This research explores the use of binder jetting based additive manufacturing process to create a novel biocomposite made of cobalt chrome and tricalcium phosphate. Experiments were conducted and processing parameters were varied to study their effect on the printing of this biocomposite. Layer thickness, binder saturation and drying time affected the dimensional tolerance and the density of the green samples. This effect is important to understand so that the material can be optimized for use in specific applications.

scholarly journals An Innovative Green Process for the Stabilization and Valorization of Organic Fraction of Municipal Solid Waste (OFMSW): Optimization of the Curing Process II Part

2019 ◽  
Vol 9 (18) ◽  
pp. 3702 ◽  
Author(s):  
Carola Esposito Corcione ◽  
Francesca Ferrari ◽  
Raffaella Striani ◽  
Paolo Visconti ◽  
Antonio Greco
Keyword(s):  
Mechanical Properties ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Urea Formaldehyde ◽  
Complete Removal ◽  
Water Soluble ◽  
Curing Temperature ◽  
Organic Fraction ◽  
Neat Resin ◽  
Selection Of

This work is focused on the optimization of an innovative and cheap process for the valorization of the organic fraction of municipal solid waste (OFMSW), through its transformation into an odorless and environmentally compatible material to be employed for building applications or as a thermal and acoustic insulator. The process starts with the grinding of OFMSW, followed by its sterilization in order to obtain a complete removal of the bacterial activity. Afterwards, the incorporation in a catalysed thermosetting matrix is carried out by mixing the OFMSW to a water soluble urea formaldehyde based resin (UF), characterized by a formaldehyde content lower than 1% wt. The OFMSW/UF blends were firstly analysed by the dynamic rheological analyses, as a function of the content of a proper catalyst, that is able to decrease the curing temperature and time. Rheological analyses results allowed the selection of times and temperatures necessary for the polymerization (T = 60 °C, t = 1 h). The effect of the presence of different additives on both the cure process and the mechanical properties of the cured samples was finally analysed, evidencing that the OFMSW/UF composites possess improved mechanical properties in comparison to that of the neat resin.

scholarly journals Chemistry, Processing, Properties, and Applications of Rubber Foams

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1565
Author(s):  
Ehsan Rostami-Tapeh-Esmaeil ◽  
Ali Vahidifar ◽  
Elnaz Esmizadeh ◽  
Denis Rodrigue
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Pressure Sensors ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Processing Parameters ◽  
Curing Temperature ◽  
Foaming Agents ◽  
Foaming Temperature ◽  
Processing Properties

With the ever-increasing development in science and technology, as well as social awareness, more requirements are imposed on the production and property of all materials, especially polymeric foams. In particular, rubber foams, compared to thermoplastic foams in general, have higher flexibility, resistance to abrasion, energy absorption capabilities, strength-to-weight ratio and tensile strength leading to their widespread use in several applications such as thermal insulation, energy absorption, pressure sensors, absorbents, etc. To control the rubber foams microstructure leading to excellent physical and mechanical properties, two types of parameters play important roles. The first category is related to formulation including the rubber (type and grade), as well as the type and content of accelerators, fillers, and foaming agents. The second category is associated to processing parameters such as the processing method (injection, extrusion, compression, etc.), as well as different conditions related to foaming (temperature, pressure and number of stage) and curing (temperature, time and precuring time). This review presents the different parameters involved and discusses their effect on the morphological, physical, and mechanical properties of rubber foams. Although several studies have been published on rubber foams, very few papers reviewed the subject and compared the results available. In this review, the most recent works on rubber foams have been collected to provide a general overview on different types of rubber foams from their preparation to their final application. Detailed information on formulation, curing and foaming chemistry, production methods, morphology, properties, and applications is presented and discussed.

scholarly journals Mechanical Properties of Polymer Concrete

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Raman Bedi ◽  
Rakesh Chandra ◽  
S. P. Singh
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Processing Parameters ◽  
Vibration Damping ◽  
Machine Construction ◽  
Polymer Concrete ◽  
Curing Conditions ◽  
Specific Strength ◽  
High Specific Strength ◽  
Selection Of

Polymer concrete was introduced in the late 1950s and became well known in the 1970s for its use in repair, thin overlays and floors, and precast components. Because of its properties like high compressive strength, fast curing, high specific strength, and resistance to chemical attacks polymer concrete has found application in very specialized domains. Simultaneously these materials have been used in machine construction also where the vibration damping property of polymer concrete has been exploited. This review deals with the efforts of various researchers in selection of ingredients, processing parameters, curing conditions, and their effects on the mechanical properties of the resulting material.

scholarly journals Geometric Accuracy and Mechanical Behavior of Polymer-Based Composite Curved Tubes produced by Fused Filament Fabrication (FFF)

2021 ◽  
Author(s):  
Asma Boumedine ◽  
Khaled Benfriha ◽  
Mohammad Ahmadifar ◽  
Samir Lecheb ◽  
Mohammadali SHIRINBAYAN ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Fibers ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Geometric Accuracy ◽  
Fused Filament Fabrication ◽  
Dimensional Precision ◽  
Geometrical Quality ◽  
Selection Of

Abstract The present study aims to assess and characterize the effect of processing parameters including infill pattern and reinforcement type on the dimensional accuracy of products manufactured by Fused Filament Fabrication (FFF) process as well as on the mechanical properties of the printed components. The reinforcements used were carbon, Kevlar and glass fibers supplied by MarkForged®; they were utilized to manufacture the PA6 matrix composite. The mechanical properties of the stated composites were compared. Finally, the results obtained confirmed that the selection of the appropriate type of the reinforcements and infill patterns among the several available types during the printing process is effective in improving the mechanical properties and also in providing a better geometrical quality of the surfaces and the consequent dimensional precision improvement of the parts printed by FFF process.

scholarly journals Síntese e caracterização do compósito zircônia/alumina para aplicação em próteses

2020 ◽  
pp. 27-37
Author(s):  
Viviane S Gomide
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Particle Size ◽  
Biomedical Applications ◽  
Human Fibroblasts ◽  
Life Quality ◽  
Mechanical Resistance ◽  
Alumina Composite ◽  
Selection Of

The need to repair or reconstruct bone tissues drives the development to biomedical applications by providing better life quality for people who need to resort to the replacement of tissues. For the selection of the material to be used, it is necessary to evaluate some fundamental factors such as: mechanical resistance and biocompatibility. Often, only one material does not have all the desired properties, requiring the formation of composites in order to guarantee the appropriate characteristics. The present work presents the mechanical properties of a ceramic zirconia/alumina composite developed for application as prostheses; cytotoxicity in human fibroblasts was tested in vitro. Compressive strength, microhardness, fracture toughness and particle size measurements were also performed.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

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