Modelling of mechanical properties of Pa6 based reinforced graphite and graphite nano platelets composites using different aspect ratio

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Muneer Umar ◽  
Michael Ikpi Ofem ◽  
Auwal Sani Anwar ◽  
Abubakar Garba Salisu

Purpose This study aims to fabricate and study the effect of five cumulative graphite (G) and graphite nanoplatelets (GNP) filler loading composites by polymerising PA6 precursor; monomer epsilon caprolactam with the two carbons in situ while taking cognisance of the mixing effects (simultaneous stirring and sonication at varying amplitudes and duration). Different aspect ratios will be used to model the two streams of polymerisations. Design/methodology/approach High viscosity extrusion grade PA6 and synthetic G of less than 2 µm particle size were used as fillers. GNP and G are dried for 6 h in vacuum oven at 90°C. Prior to in situ polymerisation, probe sonication was applied to disperse fillers in molten ɛ-caprolactam, the PA6 monomer. Five carbon loadings were made, that is 5–25 Wt.% for G and 0.5–2.5 Wt.% for GNP composites. Two different sonification regimes were applied 20% sonication amplitude for 20 min (20/20) and 40% sonication amplitude for 10 min (40/10). Findings Better tensile properties were achieved using the 20/20 processing streams for both G and GNP. The G- and the GNP-based composites systems of the 20/20 processing stream had tensile modulus and yield strength retained or improved above the unfilled PA6 value. The highest modulus obtained in the 20/20 streams are 1,878 and 1,201 MPa, respectively, for GNP and G at the highest loading levels, while the 40/10 processing streams had 963 and 1,247 MPa, respectively, for the GNP and G. Originality/value To the best of the authors’ knowledge, nobody has ever used sonification amplitude to compare mechanical properties.

2013 ◽  
Vol 750-752 ◽  
pp. 7-10
Author(s):  
Kou An Hao ◽  
Zhen Qing Wang ◽  
Li Min Zhou

Fiber impregnation has been the main obstacle for thermoplastic matrix with high viscosity. This problem could be surmounted by adapting low viscous polymeric precursors Woven basalt fabric reinforced poly (butylenes terephthalate) composites were produced via in-situ polymerization at T=210°C. Before polymerization, catalyst was introduced to the reinforcement surface with different concentration. DSC is used to determine the polymerization and crystallization. SEM is used to detect whether the catalyst existed on surface. Both flexural and short-beam shear test are employed to study the corresponding mechanical properties.


2014 ◽  
Vol 61 (5) ◽  
pp. 319-327 ◽  
Author(s):  
Mohamed Gobara ◽  
Mohamed Shamekh

Purpose – This paper aims to study both the mechanical properties and the corrosion behavior of the synthesized in situ (TiC-TiB2) particulates/AZ91 magnesium matrix composite and compare the results with that of the conventional AZ91D alloy. Design/methodology/approach – Scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were used to study the surface morphology and crystalline structure. Mechanical compression tests were used to investigate the mechanical performance according to ASTM E9-89a. The corrosion behavior of the synthesized magnesium alloy was examined using both electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques in dilute Harrison solutions. Findings – The microstructure of the Mg composite showed a uniform distribution of reinforcing phases. Also, the reinforcing phases were formed without residual intermediate phases. The addition of titanium and boron carbides not only enhanced the mechanical properties of the matrix but also improve its corrosion behavior. Originality/value – This is the first time that magnesium matrix composite has been to synthesized with TiC and TiB2 particulates starting from starting from Ti and B carbides powder without adding aluminium using practical and low-cost technique (in situ reactive infiltration technique). This paper studies the corrosion behavior of synthesized Mg matrix in dilute Harrison solution and compares the results with that of conventional AZ91D.


Holzforschung ◽  
2015 ◽  
Vol 69 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Haitao Cheng ◽  
Jie Gao ◽  
Ge Wang ◽  
Sheldon Q. Shi ◽  
Shuangbao Zhang ◽  
...  

Abstract The work aimed at the improvement of the mechanical properties of bamboo fiber-polypropylene composites (BaFPPC) by treatment of the fibers with CaCO3 at various concentrations of the solution (0.05, 0.1, 0.2, and 0.3 mol l-1). CaCO3 particles were successfully deposited in situ to bamboo fibers by means of ionic reaction of Na2 CO3 and CaCl2 aqueous solution at various temperatures. Then BaFPPC were produced, and various tests on single fibers and the composites were performed. The compatibility between BaF and PP matrix was improved by the treatments. The crystallinity of inorganic materials was significantly affected by the reagent’s concentration. A 10.4% increase in tensile strength and a 16.7% increase in tensile modulus were observed after fiber treatment with CaCO3 at a concentration of 0.2 mol l-1.


2015 ◽  
Vol 44 (6) ◽  
pp. 358-363 ◽  
Author(s):  
Lizhu Liu ◽  
Hong Zhang ◽  
Nan Zhang ◽  
Ling Weng

Purpose – The purpose of this study is to investigate the effects of two epoxy ratio and carboxyl-terminated butadiene solid rubber (CTBN) content on adhesive and flexible copper clad laminate (FCCL) performance. The epoxy adhesive used for FCCL was prepared with epoxy resin of 901 and 6128 as matrix and CTBN as toughener. Design/methodology/approach – The epoxy adhesive was prepared with epoxy resin as matrix, CTBN as toughener and 4,4′-diamino diphenyl sulfone as curing agent in solvent of butanone by mechanical agitation. The adhesives were cast on the polyimide film; subsequently, the polyimide film was dried at 160°C for 3 min to remove the solvent. Then, it was laminated with copper foil at 180°C with the pressure of 12 MPa for 3 min. The FCCL was obtained after heating for 3 h in a vacuum oven at 160°C. The structure and dielectric properties of cured adhesive, surface morphology of peeling FCCL and mechanical properties of FCCL were determined. Findings – CTBN was found to react with the epoxy resin during the curing process, with the rubber phase being precipitated and dispersed in the epoxy matrix. The relative dielectric constant and the dielectric loss tangent slightly increased with increasing CTBN content. The peeling strength of FCCL increased accompanied by a decrease of folding resistance with the increase of 901 content. Further, with the addition of XNBR, the peel strength of FCCL increased, as well as the folding resistance of FCCL, but at a higher XNBR level of 20 weight per cent, the folding resistance of FCCL tended to decrease. Research limitations/implications – In the study reported here, the effects of different epoxy resin molecular weight and CTBN content were investigated. Results of this research could benefit in-depth understanding of the influence of epoxy resin molecular weight and CTBN content on adhesive performance and could further promote the development of epoxy adhesive. Practical implications – The adhesion of epoxy adhesive prepared from epoxy resin with different molecular weight and CTBN increased, leading to the increase in peeling strength and folding resistance of FCCL. Social implications – The peeling strength of FCCL increased as the adhesion strength of epoxy adhesive increased by adding CTBN, making FCCL widely applicable. Originality/value – The mechanical properties of epoxy adhesive were increased by adding CTBN. The effects of CTBN on the microstructure and properties of FCCL were discussed in detail.


2020 ◽  
Vol 49 (4) ◽  
pp. 283-294
Author(s):  
Abd El-Wahab H. ◽  
Farouk Abd El-Monem ◽  
Naser M.A. ◽  
Hussain A.I. ◽  
El-Shahat H.A. Nashy ◽  
...  

Purpose The purpose of this paper is devoted to application of the emulsion polymer of poly(methyl methacrylate-co-butyl acrylate) prepared with in situ nano-silica as a novel tanning agent of hide to partly or totally replace chrome salt and to improve physical, thermal and mechanical properties of the tanned leather and to reduce the environmental impact of chrome tanning effluent. Design/methodology/approach Polymer/nano-silica hybrid emulsions were prepared via in situ seed emulsion polymerisation. The prepared polymers were characterised for solid content, molecular weight, viscosity, drying time, minimum film-forming temperature (MFFT) and microstructures (via transmission electron microscopy). The mechanical, thermal and surface morphological (by scanning electron microscope) properties of the treated samples were also investigated. The influences of the increase in the content of organic nano-silica on the properties of the tanned leather are discussed. Findings It was found that the viscosity, the particle size and the solid content of the prepared polymers increased as the content of the nano-silica increased while gloss and drying time of the resulting polymer film decreased. Tanning buffalo hide by Polymer F (containing a high content of nano-silica) gave desirable properties in terms of tensile strength, thermal stability and shrinkage temperature. Research limitations/implications This paper discusses the preparation and the characterisation of emulsion polymers with in situ nano-silica and their application in tanning process to enhance and improve the leather quality, as well as reduce the use of chrome tanning materials and consequently chrome tanning waste. Practical implications The tanned leather showed an improvement of physico-mechanical properties and enhancement of thermal stability. Furthermore, the tanned leather has uniform colour, softness and firmness of grain. All these promising results provide evidence to support the applicability of the prepared co-polymer/nano-silica emulsions as an efficient tanning agent that also provides lubricating properties for leather. Originality/value Since May 2015, REACH Annex XVII restricts Cr(VI) in leather articles or leather parts of articles that come into contact with skin to a concentration of less than 3 mg/kg. Cases of discovery of Cr(VI) in leather papers have been reported by the European rapid alert system on dangerous consumer products (RAPEX). The emulsion poly (methyl methacrylate-co-butyl acrylate) with in situ nano-silica that has been developed via the study reported in this paper is one of the better technologies for the reduction of chromium ratio used in tanning industry.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5066
Author(s):  
Maria Emiliana Fortună ◽  
Andrei Lobiuc ◽  
Lucian-Mihai Cosovanu ◽  
Maria Harja

In the present paper, aspects concerning the obtained and characterization of additive systems used for maximizing filler retention, and the effects on paper properties, were investigated. The effects of retention additives over properties of paper, containing fibers from in-situ loading (IS-CCP), were analyzed against the effects of additives over properties of paper containing fibers from conventional loading, obtained by the addition of calcium carbonate in precipitated form (CCP). The physico-mechanical properties were analyzed by various analyses and investigations: calcium carbonate content, X-ray diffraction, scanning electron microscopy (SEM) images, optical and mechanical properties, in order to develop the best systems of retention additives for obtaining higher retention loads for making paper with high content of nano-filler material. The obtained results reveal that at the same level of calcium carbonate content, all paper samples with in-situ loading had higher the optical and mechanical properties than the paper obtained by conventional loading in all cases the additives studied. For all studied properties, nanoparticles had a positively influence over paper properties.


2012 ◽  
Vol 66 (7) ◽  
pp. 487-490 ◽  
Author(s):  
Min Young Koo ◽  
Jae Sung Park ◽  
Min Kyu Park ◽  
Kyung Tae Kim ◽  
Soon Hyung Hong

2022 ◽  
Vol 58 (4) ◽  
pp. 171-178
Author(s):  
Elangovan Kasi ◽  
Mohan Ramakrishnan

The usage of seals in several applications like aircraft engines is mostly made of Fluorocarbon (FKM) elastomer. They are coloured products that enable easier identification based on the applications. In such seals, fillers like carbon black cannot be added to reinforce and improvise the mechanical properties since carbon black does not make it possible to add colours. The properties after ageing are also very critical in sealing application, and they must also be improved. Also, Nanocomposites are the modern and growing trends in the field of polymers that show enormous changes in the properties of the polymers without affecting their basic properties. So, the need for improvisation of FKM seals and the concept of Nanocomposites can be merged to form FKM Nanocomposites with Nano clay and Nano silica as the fillers. The objective of this project is to improve the mechanical properties, better retention of properties after ageing and after fluid interaction of the FKM seals with the aid of Nanofillers. Different proportions of FKM nanocomposites were prepared using modified Nano Kaolin Clay & modified Montmorillonite clay (Cloisite grades). Various mechanical properties like tensile strength, tensile modulus, elongation at break, compression set and tear strength etc., were studied. The test results have shown good improvements while increasing the filler loading. This is helpful to manufacture seals of desired colours thereby avoiding the difficulties faced in the carbon black-filled FKM compounds.


2017 ◽  
Vol 735 ◽  
pp. 230-234
Author(s):  
Aekkapan Sriboonrung ◽  
Siree Tangbunsuk ◽  
Chomdao Sinthuvanich ◽  
Wirunya Keawwattana

The hydroxyapatite functionalized graphene (HAp-GnP) was prepared by precipitation method. It was characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Polylactic acid (PLA)/HAp-GnP and PLA/HAp-GnP composites were prepared in film by solution casting. The amount of HAp-GnP and HAp/GnP filled in PLA was fixed at 5% (by weight). The influence of HAp-GnP in the mechanical properties including tensile strength (TS), tensile modulus (E) and elongation at break (EB) of composites was investigated. It was found that tensile strength (TS) and tensile modulus (E) of the PLA/HAp-GnP composite were higher than those of PLA/HAp/GnP composite as a result of HAp making the interfacing with graphene leading to the greater distribution of HAp-GnP in PLA matrix. The PLA/HAp-GnP composite is applicable to be applied as bone substitute in the future.


MRS Advances ◽  
2017 ◽  
Vol 2 (47) ◽  
pp. 2545-2550 ◽  
Author(s):  
Nicholas G. Betancourt ◽  
Duncan E. Cree

ABSTRACTPoly (lactic acid) (PLA) bioplastics are recyclable and biodegradable thermoplastics. They are derived from environmentally friendly sources such as potatoes, cornstarch and sugarcane. However, PLA is inherently brittle with low impact strength. The goal of this study is to improve mechanical properties of PLA by the addition of calcium carbonate (CaCO3) fillers. PLA composites were prepared by injection molding conventional limestone (LS) and white chicken eggshell (WES) powders with particle sizes of 63 μm and 32 μm in amounts of 5 wt. %, 10 wt. % and 20 wt. %. Mechanical properties such as, tensile strength, tensile modulus, and Charpy impact strengths were investigated. These three properties were evaluated and the results statistically analyzed using ANOVA F-test. For both particle sizes, the tensile strength decreased as the filler content increased, but was highest for a filler loading of 5 wt. %. In general, the 32 μm powder fillers had better tensile strengths than 63 μm sized fillers. The tensile modulus increased with filler content and was highest at 20 wt. % for both particle sizes. The LS/PLA composites had better toughness than the WES/PLA composites. The particle filler morphology and fractured surfaces were observed by scanning electron microscopy (SEM) and determined to have well dispersed particles with smooth fractured surfaces. Water absorption behavior of PLA/CaCO3 composites were studied by immersion in distilled water at room temperature for 56 days. Virgin PLA absorbed the least amount of water while the water absorption of CaCO3 composites were a function of powder type and content.


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