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The multi-walled carbon nanotubes (MWCNTs) and the poly(acrylonitrile-co-butadiene-co-styrene) (ABS) granulates are dispersed in acetone separately using a magnetic stirrer followed by ultrasonication. Further, both the solutions were mixed with magnetic stirring followed by ultrasonication. Neat-ABS film, 0.25 wt%, 0.5 wt% and 1 wt% of MWCNT-ABS nanocomposite films of the average thickness of 140 µm are fabricated by the solution molding using a petri dish, followed by room temperature curing and further hot compression to maintain uniform thickness. The tensile properties, thermal stability, electrical conductivity, and EMSE of all films are investigated. The results indicate that the addition of MWCNTs to ABS enhanced the mechanical properties and electrical conductivity, thermal stability, and EMSE. The 0.25 wt% MWCNT-ABS nanocomposite films show attractive mechanical, electrical, thermal, and EMSE as compared to neat-ABS films. More than 0.25 wt% MWCNTs in the ABS matrix deteriorates the tensile strength. However, 0.5 wt% MWCNT-ABS nanocomposites exhibit better tensile strength, Young’s modulus, electrical conductivity, and EMSE than neat-ABS. In this research, we used a low quantity of MWCNTs and followed a one-time heating process in the entire fabrication, and produced MWCNT-ABS nanocomposite films with reasonable properties. Hence, this may be one of the options to produce nanocomposites suitable for EMS materials. We recommend that these films may be used as interlayers to develop an X-band range electromagnetic wave shielding material.

Multiwalled Carbon Nano Tube (MWCNT) filled glass fabric reinforced epoxy composites (MWCNT/GEC), and neat GEC were prepared by hand-lay-up followed by hot compression molding method. As per the ASTM standard, specimens were prepared and investigated the influence of the addition of MWCNTs on flammability properties of GEC through the UL-94 vertical flammability test and the limiting oxygen index (LOI) method. The thermal degradation was studied by thermogravimetric analysis (TGA). It was found that the GEC improved upon the thermal stability and fire-retardant properties due to the addition of MWCNTs. It was observed that the 0.3 wt.% MWCNTs-glass fabric reinforced epoxy composite (0.3MWCNT/GEC) exhibits better properties than neat GEC and 0.075 wt.% MWCNT-glass fabric reinforced epoxy composite (0.075MWCNT/GEC) and 0.15 wt.% MWCNT-glass fabric reinforced epoxy composites (0.15MWCNT/GEC). Hence, this material may be suitable for electrical devices and appliances based on the other required properties’ further fulfillment.

A study of high-velocity impact behavior of multi-layer nanopolymer composites has been one of the most exciting research topics in materials science and engineering. The material researchers and designers developed and investigated the behavior of advanced materials suitable for impact resistance. Background information and current research activity in the field of fiber-reinforced hybrid nanopolymer composites are briefly reviewed. The factors influencing the performance of the polymer composites and failure mechanisms when subjected to high- velocity impact are presented. The ballistic properties of some representative composite materials containing Carbon, Glass, Kevlar, and hybrid fabric reinforced with suitable nanophase are briefly discussed. The material characterization methods and test standards are highlighted. A systematic approach that facilitates the formulation and fabrication of application-specific, ballistic properties-centered, and tailor-made design of polymer nanocomposites helps the scientific community achieve the desired material sufficiency. Such information can have important implications in the design of more sophisticated systems for a wide range of applications

Natural fiber reinforced polymer composites have proved to be fit for use in several structural and functional applications. Jute fiber reinforced epoxy composites are one of the most preferred natural fiber-based polymer composites. The emerging need for high strength application while considering environmental sustainability and with the advent of bio-composites, the researchers, in recent times, started showing interest in incorporating the various bio-based resins in the composites. The present work thus aims at investigating the possibilities of making jute fiber reinforced epoxy composites with alkali-treated fibers and cashew nut shell liquid blended epoxy resins. The feasibility is tested through the mechanical properties, which is quantified using tensile strength and flexural strength. The modified matrix in the prepared composites is based on the variation in the weight percentage of cashew nut shell liquid (25 and 30%). The results indicate that it is possible to make better composites using the modified matrix and alkaline treated jute fibers as the mechanical properties outperform the jute fiber reinforced epoxy composites made using conventional epoxy resin and untreated jute fibers. The best amongst all the variants made, the one that proved to be the best JFRE composite is having alkaline treated fiber and blend 2, which exhibits an average tensile strength of 679 MPa, and flexural strength of 88.83 MPa.

Fiber-reinforced polymer (FRP) composites are widely being used for structural applications due to their attractive properties. Particularly, to fabricate complicated structures by FRP comp...

Green composites, because of its economic advantages and contribution to environmental sustainability, finds its wide range of applications in several industrial sectors. Mechanical characterization of any engineering materials is of utmost importa

Hybrid filler loaded multi-layer polymer composites are becoming one of the suitable alternative material for electromagnetic interference shielding (EMIS) applications. Mainly these composites are manufactured by conductive/magnetic fabrics, foams, foils or films or a combination of all, layered in an orderly architecture to obtain effective EMIS. In this work, dendrite structured copper particulate dispersed in cellulose acetate polymer (CA). We have developed approximately 100-micron thickness of cellulose acetate/copper filler (CA/Cu) films (7–55 wt%) and a neat CA film. The electrical conductivity, tensile strength, percentage of elongation, burst strength and folding endurance of CA/Cu films were measured and compared. The percolation threshold for conductivity was found at 28 wt% and the drastic increase in conductivity at 28–37 wt%. The mechanical strength of CA/Cu composite films was investigated and reported.

Multi-layered carbon fabric-epoxy composites (CFEC) encounter certain challenges in expanding their usage mainly due to their low interlaminar shear strength (ILSS) and sensitivity to delamination damage. The present article focuses on evaluating the effectiveness of the fillers molybdenum disulfide (MoS2) and hexagonal boron nitride (h-BN) (2–8 wt%) on the flexural and the shear properties of the CFEC. The filler dispersion in epoxy resin is achieved by ultrasonication and composite fabrication through vacuum-assisted hand lay-up process. The filler surface area, evaluated as per nitrogen adsorption principles, reveals characteristics of hysteresis isotherm and mesoporous structure in both the fillers. Fourier transform infrared analyses on MoS2 reveal the stretch vibration due to molybdenum-sulfur and disulfide bonds whereas, in the h-BN, the transverse stretching and the out-of-plane bending happen due to boron-nitrogen and the boron-nitrogen-boron molecular group, respectively. Further analysis in the atomic force microscope shows more regular filler distribution at the outer surface for 4 and 6 wt% filler loaded CFEC whereas, 8 wt% filler loading results in an uneven particle distribution and attains the minimum surface roughness. The study exhibits the maximum ILSS (43.46 MPa) which is 43% enhancement compared to the neat CFEC for 6 wt% h-BN loaded CFEC. The maximum flexural strength (532 MPa) was noticed in 4 wt% MoS2 loaded CFEC signifying 62% improvement compared to the neat CFEC. The structural property improvements were witnessed because of the regularly distributed filler that strengthens the fiber-matrix interaction zone and reduces the matrix crack. The findings reveal that the proposed enhanced scheme by solid lubricant fillers proves to be more favorable for improving the matrix-dominated properties and the bending stiffness compared to the other particle-reinforced approaches.

Banana short fiber/Al(OH)3/epoxy composite laminates were prepared by dispersing short banana fiber and Al(OH)3 particulates in an epoxy matrix and investigated for their specific wear rate...

Cryogenic treated multilayered carbon fabric/oxidized multiwall carbon nanotube/epoxy (CCF/O-MWCNT/E) composite and untreated carbon fabric/epoxy (CF/E) composite were prepared by hot compression molding technique. The density and mechanical properties such as tensile properties, flexural properties, interlaminar shear strength, and microhardness of the composites were investigated as per ASTM standards. The wear and coefficient of friction behavior were investigated using computer interfaced pin-on-disc test rig at room temperature for varied load and sliding speed. The morphology of worn surfaces of the wear test composite specimens were studied by scanning electron microscope. It is found that the synergetic effect of addition of O-MWCNT to epoxy matrix and cryogenic treatment of carbon fabric improved the wear resistance and mechanical properties. Also, a thin lubricating film developed by the oxidized multiwall carbon nanotube/epoxy wear debris reduces the coefficient of sliding friction and wear rate.

Neat glass fabric/epoxy composites (GECs) and multi-wall carbon nanotube/glass fabric/epoxy composites (MWCNTGECs) were prepared by hand-lay-up followed by compression molding technique and investigated the structural properties. It is found that the mechanical properties and wear resistance of the glass fabric reinforced epoxy composite improved upon the addition of MWCNTs. The 0.3 wt%MWCNTs filled glass fabric/epoxy composite (0.3MWCNTGECs) exhibits better properties as compared to 0.075 wt% MWCNT filled glass fabric/epoxy composites (0.075MWCNTCs), 0.15 wt% MWCNT filled glass fabric/epoxy composites (0.15MWCNTCs) and GECs. The mechanism of wear failure of these composites was analyzed from the morphology of worn surfaces. It was observed solid lubricant film established on the wear track at higher normal loads reduces the wear. The correlation of Vickers's hardness and Lancaster factor ( σ e ) − 1 with specific wear rate is investigated and reported.

Cu2SnSe3 has been considered as a potential thermoelectric material owing to its cost-effective and nontoxic constituent elements along with its high electrical conductivity. However, its low Seebeck coefficient has been a concern towards realizing a high figure-of-merit. In the present study, Cu2SnSe3/xSnSe (x = 0, 5, 10, and 20 wt %) composite samples whose thermoelectric performance has been studied in the temperature range 10–375 K, shows that the Seebeck coefficient of sample containing 10% SnSe is ~3.6 times that of the pure. The incorporation of SnSe has resulted in a significant increase in electrical resistivity and Seebeck coefficient which is attributable to the decrease in carrier concentration with increase in SnSe content. Concurrently, a power factor (PF) of 35.60 μW/mK2 has been attained for x = 10% sample at 375 K. However, due to the increase in thermal conductivity with the addition of SnSe, the composites have lower ZT values than that of the pristine Cu2SnSe3 sample. Furthermore, the Vicker's microhardness, which is a key measure for the mechanical strength of a material, has distinctly improved by the addition of SnSe.

Aim: To compare the incidence of apical root crack formation after root canal preparation at different instrumentation lengths using ProTaper Universal (PTU), ProTaper Next (PTN) and ProTaper Gold (PTG) file systems. Subjects and Methods: Eighty-four mandibular first premolars with single and straight root canal were mounted in resin block after simulating periodontal ligaments. 1–2 mm of root apex was exposed followed by sectioning of 1 mm of root tip for better stereomicroscopic visualization. While the Control group was left unprepared, experimental groups were instrumented up to root canal length (RCL) and (RCL-1 mm) respectively using PTU, PTN and PTG. After staining the root apex with 1% methylene blue dye, stereomicroscopic images were obtained for evaluating apical root cracks. The data were analyzed using Chi-square, phi and Cramer test. The significance level was set at P < 0.05. Results: Significantly less dentinal defects were seen between PTG and PTU while there was no significant difference between PTU-PTN and PTN-PTG. Furthermore, samples instrumented up to RCL-1 mm showed lesser cracks as compared with samples instrumented up to RCL. Conclusion: PTG produced least number of cracks followed by PTN and PTU. Furthermore, instrumenting short of RCL reduced the crack formation risk.