Investigation of Particulate Filtration of Alumina Nano-Particles in VARTM Processing of Hybrid Composites

Author(s):  
Oladapo Akinyede ◽  
Jag Sankar ◽  
Ram Mohan ◽  
Ajit Kelkar

Hybrid composites composed of particulate inclusion in the resin for fiber reinforced plastics are manufactured using the low-cost vacuum assisted resin transfer molding (VARTM) composite technology. Particulate inclusions are known to influence to some degree, the thermo-mechanical properties of resin systems and are dispersed in the resin before fabrication by this low cost processing technique. Particulates are dispersed in resin systems via ultrasonic agitation to obtain exfoliated/ intercalated particle dispersion morphology. Highly dispersible grade particulate boehmite nano-alumina with 110nm mean particle size was pre-dispersed in a low viscosity epoxy resin prior to VARTM processing. Fiber lay-up with high tow density (10K) S-glass fabric was impregnated. The flow regime of the infused modified resin and the mold setup configuration influence the percolation and filtration of the particulates in the mold lay-up. The occurrence of filtration depends on the mold lay-up configuration and flow regime. The flow pattern is varied to induce filtration by transverse percolation through the distribution media and through-fabric longitudinal flow schemes (without distribution media). Resin samples from the flow front were collected and are studied via thermo-gravimetric analysis (TGA). The dynamics of particulate flow and the potential filtration effects due to the fiber lay-up during the infusion of low viscosity resin are studied. These are based on analyzing the residual mass of the 110nm alumina particles in epoxy resin that is collected after infusion through the fiber lay-up during the manufacture of advanced hybrid composite.

2020 ◽  
Vol 49 (6) ◽  
pp. 473-482
Author(s):  
H. Abd El-Wahab ◽  
G.A. Meligi ◽  
M.G. Hassaan ◽  
L. Lin

Purpose The purpose of this study is to prepare, characterise and evaluate nano-emulsions of ter-polymers of various compositions as eco-friendly binders for flexographic ink industry. Design/methodology/approach Various nano-emulsions of ter-polymers were prepared based on Vinyl acetate, Vinyl Versatate, butyl acrylate, acrylic acid and acrylamide monomers by means of a conventional seeded emulsion polymerisation technique, using K2S2O8 as the initiator. The characterisation of the prepared emulsions was performed using Fourier transform infrared, thermo-gravimetric analysis, gel permeation chromatography and transmission electron microscopy. A selection of co-polymers and ter-polymers were formulated with pigments and additional ingredients, as water-based flexographic inks. The inks were characterised for their rheological properties, pH, degree of dispersion, water-resistance and colour density. Findings It was found that the low viscosity of the prepared polymers may reduce the film thickness of the flexographic inks and may also increase the spreading of the ink on the surface. As a result, stable modified poly acrylate-based latex with improved physico-mechanical properties was obtained. The prepared latexes showed improved properties such as enhanced thermal stability and better water resistance. The effect of the emulsifier type on the properties of the resulting emulsion latexes and their corresponding films were investigated. Also, as the hydrophobic monomer increases, so does the colour density and increasing the binder ratio enhances the gloss values. The improving in gloss values were obtained and provide excellent adhesion properties for both the pigment particles and the base paper. Research limitations/implications The study focusses on the preparation of new water-based ter-polymer nano-particles and their use as eco-friendly binders for flexographic ink industry. Ink formulations based on other different type emulsion polymers could also be studied to assess the applicability of the ink formulation system found for other binders. Practical implications The ink formulations developed could find use in industrial-scale printing. Originality/value Eco-friendly environment and low-cost ink formulations for printing on paper substrates are novel.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
K. Manohar Reddy ◽  
D. Harsha Vardhan ◽  
Y. Santhosh Kumar Reddy ◽  
Gujjala Raghavendra ◽  
Ramesh Rudrapati

The advancement of composites mixed with natural fibers and with fillers has become the most supportable alternative material for engineering applications, especially in industries such as automotive and aerospace. Natural fibers are renewable, cheap, biodegradable, and ecological materials. In the present work, already used woven jute fibers, which are extracted from gunny bags with the same grams per square meter (GSM), were used, and then, woven jute fibers were chemically treated to improve their characteristics. Graphite powder-filled used jute fiber reinforced epoxy composite (UJF) are prepared by using the hand-layup technique. Tests such as tensile, flexure, impact, and thermo-gravimetric analysis (TGA) were conducted. These tests were according to ASTM standards to evaluate the effect of graphite filler content on hybrid epoxy jute composites. The composite material is prepared by changing the content by weight of the filler by 3%, 6%, 9%, and 12%. The experimental results reveal that 6% of the graphite composites showed the maximum tensile strength and modulus. With the increase in the filler content, there is a decrease in the flexural properties. The impact resistance increases slightly up to 6% of the filler content. The study of thermal decomposition showed that the lowest mass loss was found at 9% by weight of the filler content. Morphological analysis performed by FE-SEM showed that the addition of filler content improved the binding of the fiber and matrix up to 6% by weight of the filler content. It should be noted that these hybrid composites are a promising material at low cost for lightweight structural applications.


2020 ◽  
Vol 13 ◽  
Author(s):  
Inbasekaran S. ◽  
G. Thiyagarajan ◽  
Ramesh C. Panda ◽  
S. Sankar

Background:: Chrome shavings, a bioactive material, are generated from tannery as waste material. These chrome shaving can be used for the preparation of many value-added products. Objective:: One such attempt is made to use these chrome shaving wastes as a composite bio-battery to produce DC voltage, an alternate green energy source and cleaner technology. Methods:: Chrome shavings are hydrolyzed to make collagen paste and mixed with the ferrous nanoparticles of Moringa oleifera leaves and Carbon nanoparticles of Onion peels to form electrolyte paste as base. Then, the electrolyte base was added to the aluminum paste and conducting gel, and mixed well to form composite material for bio-battery. Results:: The composite material of bio-battery has been characterized using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). Series and parallel circuit testing were done using Copper and Zinc electrodes or Carbon and Zinc electrodes as the battery terminals in the electrolyte paste. The surface area of these electrodes needs standardization from bench to pilot scale. The power generated, for an AA battery size, using a single bio-battery cell has produced a DC voltage of 1.5 V; current of 900 mA. Circuit testing on 1 ml of 80 well-cells connected in series has produced DC output of 18 V and 1100 mA whereas 48 V and 1500 mA were obtained from a series-parallel connection. Conclusion:: The glass transition temperature (Tg) of electrolyte of the bio-battery at 53°C indicates that, at this temperature, all the substances present in the bio-battery are well spread and contributing consistently to the electrolyte activity where Fe-C-Nano-Particles were able to form strong chemical bonds on the flanking hydroxyl group sites of the Collagen leading to reduced mobility of polymers and increase Tg. The results instigate promising trends for commercial exploitation of this composite for bio-battery production.


2019 ◽  
Vol 6 (10) ◽  
pp. 190690
Author(s):  
Zhongkan Ren ◽  
Christel Gervais ◽  
Gurpreet Singh

Ceramic matrix composite (CMC) materials have been considered a desired solution for lightweight and high-temperature applications. Simultaneously, among all different CMC reinforcements, polymer-derived ceramic (PDC) fibres have gained attention for the intrinsic thermal stability and mechanical strength with simple and cost-effective synthesis techniques. Here, carbon-rich SiOCN fibres were synthesized via hand-drawing and polymer pyrolysis of a hybrid precursor of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasilazane (TTCSZ) and poly-acrylic acid (PAA). The type of silazane reported in this work is considered as a major precursor for SiCN; however, it is unspinnable, due to its unfavourable physical properties (low viscosity) and chemical structure (cyclic rather than linear structure). The introduction of PAA to TTCSZ to create a hybrid precursor remarkably improved the spinnability of the silazane and should be widely applicable to other unspinnable PDC pre-ceramic polymers. Investigations on the structural and compositional development of the fibres were mainly conducted via Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance and thermo-gravimetric analysis to determine spinnability, free carbon content, cross-linking and pyrolysis behaviour of the fibres, respectively.


2017 ◽  
Vol 898 ◽  
pp. 2302-2308
Author(s):  
Jin Li Zhou ◽  
Shu Zhu ◽  
Wen Pin Jia ◽  
Chao Cheng ◽  
Elwathig A.M. Hassan ◽  
...  

In order to improve the toughness of epoxy resin, hydroxyl-terminated polyethersulfone (PES) with various amounts (0 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%) were added to bisphenol A epoxy resin (DER331)/ curing agent DETDA (E100) systems, and the influence of PES contents on curing process and heat-resistance was studied. Non-isothermal DSC was used to determine the curing process of uncured DER331/E100/PES systems at heating rate of 2°C/min, 5°C/min, 7°C/min, 10°C/min and 15°C/min separately, and the apparent activation energy was calculated based on Kissinger method. The morphology of the etched cured DER331/E100/PES systems with different PES contents was observed by SEM. The heat-resistance of these systems was investigated by DSC and TGA. The results showed that with the increasing of PES content the curing exothermic peak, the heat of curing reaction, the initial and final curing temperature all decreased at the first and then increased, indicating that when the PES content was low (5 wt.%, 10 wt.%), PES can facilitate the curing process, while, when PES content up to 15 wt.%, PES can prevent or weaken the curing reaction. SEM results indicated that the phase structure changed drastically depending on the PES content. The systems with 5 wt.% and 10 wt.% PES were epoxy-rich phase, with 15 wt.% PES was co-continuity phase, and with 20 wt.% PES showed complete phase inversion (PES rich phase). The glass transition temperature and thermo gravimetric analysis demonstrated that the addition of PES can increase the heat resistance of cured DER331/E100/PES systems.


2010 ◽  
Vol 71 ◽  
pp. 28-33 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Renato Meneghetti Peres ◽  
L.H. Silveira ◽  
Leonardo Gondim Andrade e Silva ◽  
L.F. de Miranda

Nanocomposites are nanometrical material particles embedded in a specific matrix. The degree of organization of the nanostructures and their properties depend on the nature of the organic and inorganic components of the structure that can generate synergic interactions. Polymeric nanocomposites are related to a class of hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. In the present work, nanocomposites of nylon 6,12 with different concentrations of pseudoboehmite obtained by sol-gel process were prepared with and without the presence of octadecylamine. After preparation, the samples were irradiated with a 200 kGy radiation dose in an electron accelerator. The pseudoboehmite nano particles were characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermo gravimetric analysis. The nanocomposites were characterized by thermal and mechanical tests. The addition of pseudoboehmite promoted a reduction of the melting flow during the production of the composites evidencing the interaction of pseudoboehmite with the polymeric matrix, probably modifying its crystalline structure.


2019 ◽  
Vol 814 ◽  
pp. 3-11
Author(s):  
Xiang Yu Ren ◽  
Hui Chen ◽  
Jing Wu ◽  
Hong Bo Liu

Microcrystalline graphite (MG) was used as raw material and oxidated by Hummers method. And further the graphene oxide (GO) was obtained by ultrasonic stripping. The TP modified graphene (TPG) was prepared by the surface grafting of pure natural green tea extract tea polyphenols (TP) on the surface of GO. Finally, the TPG/epoxy resin composite was prepared by solution blending and heat-curing moulding method.The characterization of structure and properties of TPG was analyzed by X ray diffraction pattern (XRD), infrared spectroscopy (FT-IR), thermo gravimetric analysis (TGA) and X ray photoelectron spectroscopy (XPS). A universal material testing machine was used to test the mechanical properties of epoxy resin composites with different addition of TPG. Field emission scanning electron microscopy (SEM) was used to observe the tensile-sectional morphology of the composites. The thermal stability of the composites was investigated by thermogravimetry and thermal dilatometer. The experimental results showed that the TP molecule was successfully grafted on the oxygen-containing functional groups of the GO surface through the phenolic hydroxyl group.When the addition of TPG was 1.0 wt%, the decomposition temperature of the epoxy resin was increased by 22.2 °C,and the surface resistivity decreased from 1.35×1014 Ω·m to 1.7×109 Ω·m. When the added amount of TPG was 0.5 wt%, the tensile strength of composites was increased by 13.5% reaching 59.85 MPa.


2014 ◽  
Vol 32 (2) ◽  
pp. 214-219 ◽  
Author(s):  
Guojun Cheng ◽  
Jiaqi Luo ◽  
Jiasheng Qian ◽  
Jibin Miao

AbstractTitanium nitride (TiN) nano-particles were subjected to graft modification by silane coupling agent (KH-570) via a direct blending method. The hydroxyl groups on the surface of TiN nano-particles can interact with silanol groups [-Si-OCH3] of KH-570 forming an organic coating layer. The covalent bonds (Ti-O-Si) formation was testified by Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS). Through transmission electron micrograph (TEM) observations, it was found that KH-570 could improve the dispersibility of nano-TiN particles in ethyl acetate. Thermo gravimetric analysis (TGA) and contact angle measurements indicated that KH-570 molecules were adsorbed or anchored on the surface of nano-TiN particle and the net efficiency of it was 22.76 %, which facilitated to hinder the aggregation of nano-TiN particles.


2013 ◽  
Vol 12 (02) ◽  
pp. 1350008 ◽  
Author(s):  
TARIG A. HASSAN ◽  
VIJAYA K. RANGARI ◽  
FREDRIC BAKER ◽  
SHAIK JEELANI

In the present investigation, silicon carbide (β-SiC) nanoparticles (~ 30 nm) were coated on silicon dioxide (SiO2) nanoparticles (~ 200 nm) using sonochemical method. The resultant hybrid nanoparticles were then infused into SC-15 epoxy resin to enhance the thermal and mechanical properties of SC-15 epoxy for structural application. To fabricate an epoxy-based nanocomposite containing SiC/SiO2 hybrid nanoparticles, we have opted a two-step process. In the first step, the silica nanoparticles were coated with SiC nanoparticles using high intensity ultrasonic irradiation. In a second step, 1 wt.% of as-prepared SiC/SiO2 particles were dispersed in epoxy part-A (diglycidylether of bisphenol A) using a high intensity ultrasound for 30 min at 5°C. The part-B (cycloaliphatic amine hardener) of the epoxy was then mixed with part-A- SiC/SiO2 mixture using a high-speed mechanical stirrer for 10 min. The SiC/SiO2 /epoxy resin mixture was cured at room temperature for 24 h. The SiC nanoparticles coating on SiO2 was characterized using X-ray diffraction (XRD) and high resolution transmission electron microscope (TEM). The as-prepared nanocomposite samples were characterized using thermo gravimetric analysis (TGA) and differential scanning calorimeter (DSC). Compression tests have been carried out for both nanocomposite and neat epoxy systems. The results indicated that 1 wt.% (SiC) + (SiO2) loading derived improvements in both thermal and mechanical properties when compared to the neat epoxy system.


2015 ◽  
Vol 764-765 ◽  
pp. 107-110 ◽  
Author(s):  
Ming Ming Yu ◽  
Bin Feng ◽  
Min Yang ◽  
Li Qi Liu ◽  
Hong Li ◽  
...  

In order to improve the toughness of the cured aromatic tetrafunctional epoxy resins in the premise of influencing the thermal properties as little as possible, the aromatic tetrafunctional epoxy named N,N,N’,N’-tetraglycidyl-4,4’-diaminodiphenyl ether (TGDDE) was modified by a dimer carboxylic acid (DFA), and then the epoxies were cured with methyl nadic anhydride (MNA). In the present work, the toughness was characterized with the impact resistance tested by pendulum impact testing. Besides, the thermal properties of the cured epoxy resin were investigated with the thermo-gravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The impact testing results indicated that the toughness of the cured resins could be improved after the modification and increased with the increasing content of DFA. The thermal analysis showed that the thermal properties of the cured resins were not influenced obviously since the thermal stabilities of the products could be improved and the glass transition temperature of them were not influenced obviously when the tetrafunctional epoxy modified with appropriate content of DFA.


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