Enhancement In Properties Of Composites Research Articles

Waste Coir Nanofiller Fused Gallus-Gallus Fibres Reinforced PMC

This research aims to increase the utility of globally and abundantly available waste natural fibres of Gallus-Gallus fibres coir waste from mattress and car seat manufacturing factories. The composite samples were prepared with a rally round of polyester resin of grade GP500 bio-epoxy by synthesizing specially treated Gallus-Gallus fibres selectively used for reinforcement and characterizing them through static and dynamic mechanical analyses to identify their wide range of applicability. The Gallus-Gallus fibres are preprocessed with sodium oxidative and a half per cent of potassium manganate (VII) chemical solution. The selective use includes 5 mm, 10 mm, 15 mm, and 20 mm length of the Gallus-Gallus fibre, and the quantity of reinforcement was 10%, 20%, and 30%. Five alternate layers of matrix and fibres, with vertical and horizontal orientation, are considered; 12 different samples of Gallus-Gallus fibres reinforced polyester polymer composites and a neat polyester composites were synthesized and characterized for moisture absorbability, tensile strength, tensile modulus, flexural strength, flexural modulus, wear resistance, and outperformed composites were included in microscopic examination and dynamic Mmchanical analysis. The interesting results are the preferred resin, supported for good surface finish, interface bonding, and totally in the enhancement of Composite properties. The composites are strong in tension (760.89 MPa) and sufficiently flexible (flexural modulus 5441.32 MPa), absorbed less moisture (5.8 g), high wear-resistant (least weight loss upon abrasion with a value of 0.1989 g), secured good results in dynamic analysis, and ensured homogeneous distribution of fibres in the matrix through a scanning electron microscopy image. The composites CPPC10, CPPC11, and CPPC12 performed well but composite CPPC12 outperformed.

Precise role of zirconia to boost up the mechanical, thermal, viscoelastic, dielectric, and chemical resistance properties of natural rubber-nitrile rubber blend

Silica and other metal oxides have been emerged as potential substitutes of conventional carbon black (CB) to reinforce elastomeric materials. It not only steers clear of the ill-effects of CB such as issues like carcinogenicityand carbon footprint but they can impart rich thermal, optical, dielectric, and antimicrobial properties to the composites in addition to appreciable reinforcement. Silica is of special mention in this context while titania and zirconia to follow next. In this work, we report efficacy of zirconia towards property enhancement of a rubber blend comprised of non-polar natural rubber (NR) and polar nitrile rubber (NBR). Designed and controlled incorporation of zirconia in rubber matrix via an in-situ approach offers appreciable reinforcement to the composites. This is due to the fine dispersion of zirconia in elastomer matrix (SEM), efficient rubber-filler interaction (DMA) and increased crosslinking densities (swelling study). Analysis by atomic force microscopy (AFM) and differential scanning calorimetry (DSC) indicates that in-situ zirconia acts in favour of improved blend compatibility as well. All these factors offer notable impact on the other composite properties viz. improved thermal stability, enhanced flame retardancy and excellent chemical resistance to the blend composites. Additionally, dielectric properties become better upon incorporation of in-situ zirconia. The enhancement of composite properties becomes more prominent upon surface modification of in-situ zirconia by an organosilane Bis-(3-triethoxysilylpropyl) tetrasulfide (TESPT). Superiority of in-situ zirconia over externally filled zirconia has been established by a comparative analysis. Hence, current study offers valuable insights on the potential of in-situ zirconia as a substitute of CB to reinforce the rubber blends. The findings have important implications for the development of high performance elastomeric composites that can sustain in harsh service conditions.

Development of an innovant carbon/jute porcine‐bone hybrid material for sustainable composite manufacturing

AbstractThe recent decade has witnessed significant innovations and research in the field of hybrid composites. This rapid growth warranted the development of lightweight composite with higher mechanical strength. The use of bio‐waste like cow bone powder and fishbone powder from food industries has shown significant enhancement in the mechanical properties of composites in recent past. Owing to the large number of pigs slaughtered daily for meat, porcine bones are readily available. Most of the time, these bones end up as waste, polluting the environment. In view of this, an attempt has been made to develop a sustainable and innovant hybrid composite using porcine bone powder (PBP) as filler, and carbon/jute fibers as reinforcement in a polyester matrix. The compression molding technique was used to develop the hybrid composite. Characterization of the developed composite was investigated by image processing, scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy analysis. The influence of PBP percentage and size, on tensile strength, impact strength, and surface hardness were studied as per ASTM standard. In addition, the effects of alkali treatment of jute fiber on the above‐mentioned responses have also been studied. It was found that the mechanical strength of the hybrid composite was enhanced by the addition of PBP and alkali treatment. SEM images revealed that PBP with size 50–200 μm and weight percent from 10% to 15% demonstrated good bonding with the fibers. The developed hybrid composites demonstrated to be a sustainable solution to the bio‐waste management from the food industry.

Physico-Mechanical Properties of Treated Chicken Feather–Reinforced Unsaturated Polyester Resin Based Composites

The influence of chemical treatment on the mechanical properties of treated chicken feather fibre-reinforced unsaturated polyester resin (TCFF-UPR) composites was studied in this research. Redundant portions of chicken from poultry farms are comprehensively contaminating the environment. To minimize environmental pollution, these redundant portions need to use for the production of other materials. In this study, we used chicken feather for the preparation of useful composites combining with unsaturated polyester resin (UPR) to reduce environmental pollution. The composites were prepared successfully by conventional hand lay up technique using modified chicken feather as the reinforcing phase of composites. For preparing composites different percentages (2, 5, 7, 10, 12 and 15% by weight) of fibre were used. Attained tensile test results expressed significant enhancement in the tensile properties of composites, with the optimum combination of tensile strength presented by 5 wt% , tensile modulus presented by 10 wt% untreated chicken feather bio-fibre reinforcement and bending strength by 5 wt% chicken feather bio-fibre reinforcement.

Nano and bio-composites and their applications: A review

Recent developments in the materials science field have highlighted the need for further composite materials study, especially with regard to bio and nano-composites, as their abilities to meet modern requirements with regard to facilitating technological advancement is far greater than those of monolithic materials. There are several advantages to nano and bio-composites as compared to conventional materials, including properties such as fatigue resistance, impact resistance, stiffness, corrosion resistance, biodegradability, thermal conductivity, low relative density, environmentally friendly waste stages, and high specific strength. Recent years have seen the discovery of several new high-performing composite materials, and improvements in the fields of aviation, automobile, adhesion, building, and electronic engineering also support the adoption of more general utilisation of nano and bio-composites in a much wider range of applications than those for which they were originally designed. This paper thus highlights and reviews information on bio- and nano-composite materials to determine current trends in how these materials are used in the various fields of engineering in numerous applications, and to examine the role of nanotechnology in the enhancement of composite properties.

Evaluating the efficacy of a newly developed palm-based process aid on nitrile rubber composites

The exploration of bio-based process aid is still ongoing in the effort to replace petroleum-based process oil. In this study, the efficacy of a newly developed palm-based process aid (Bio) on nitrile rubber (NBR) composites was investigated by varying its concentration from 0.0 to 10.0 phr. A comparison was made against a commercial oil (CO), i.e. naphthenic oil in terms of Mooney viscosity, cure characteristics, morphology, physical, and chemical properties. Results revealed that the use of Bio as process aid improves the processability of rubber by lowering the Mooney viscosity, enhancing filler dispersion, and lowering loss tangent values. Tensile properties and compression sets of CO-NBR composites were slightly better compared to Bio-NBR composites. Interestingly, Bio-NBR composites showed better ageing properties, especially at higher process aid content. Higher retentions of tensile strength and elongation at break and lower compression sets of aged Bio-NBR compared to CO-NBR composites were observed, which are possibly contributed by the good compatibility of Bio with aged rubber. Thermogravimetric analysis showed that the thermal stability of Bio-NBR composites were slightly better than CO-NBR composites. Based on these findings, the use of Bio (≥ 7.5 phr) as process aid significantly improved the processability of rubber with some enhancement in ageing properties of composites that is desirable and ideal for various applications such as for the production of automotive components.

Enhancement of fiber-matrix interface of recycled cotton fibers reinforced epoxy composite for improved mechanical properties

The aim of this study is to enhance the fiber-matrix interface of cotton waste reinforced composite panels by a specific chemical treatment. For this purpose, cotton fibers are treated in sodium hydroxide (NaOH) solution with three different concentrations (0.5 M, 1 M, and 1.5 M) and three different soaking times combinations (1 h, 3 h, and 5 h). Mechanical evaluation of treated and untreated reinforcements and composite panels are characterized using tensile test whereas the chemistries of fiber reinforcements are investigated using Fourier-transform infrared spectroscopy analysis and the fiber-matrix interactions are morphologically examined using scanning electron microscopy. Results indicate a remarkable enhancement in mechanical properties of composites via improving the interfacial adhesion and compatibility between fiber and matrix with a significant increase of Young modulus up to 270% for reinforcements and to 70% for composite materials compared to untreated materials.

Microstructural and mechanical properties of biocomposites made of native starch granules and wood fibers

Novel biocomposites were fabricated using preforms of unmodified starch powder and wood pulp fibers. Stacks of preforms were consolidated using thermo-compression (TCM) and ultrasonic compression moldings (UCM). The characterization of the microstructure of the biocomposites showed that TCM enabled a better preservation of the crystallinity of starch granules during their welding than UCM. However, UCM allowed a significant gain in processing time. For the best set of forming and material parameters, the composites exhibited an elastoplastic response with strain hardening. Their Young's modulus, flexural strength and strain at ultimate stress reached up to approx. 6 GPa, 70 MPa, and 8%, respectively. The best properties were associated to the partial preservation of the native crystallinity of starch and lowered porosity. Bleached and fibrillated fibers with a large aspect ratio also contributed to the enhancement of composite properties. These effects were explained by a better starch-fiber interface and the presence of a network of connected fibers within the composites.

Intragranular Dispersion of Carbon Nanotubes Comprehensively Improves Aluminum Alloys.

The room‐temperature tensile strength, toughness, and high‐temperature creep strength of 2000, 6000, and 7000 series aluminum alloys can be improved significantly by dispersing up to 1 wt% carbon nanotubes (CNTs) into the alloys without sacrificing tensile ductility, electrical conductivity, or thermal conductivity. CNTs act like forest dislocations, except mobile dislocations cannot annihilate with them. Dislocations cannot climb over 1D CNTs unlike 0D dispersoids/precipitates. Also, unlike 2D grain boundaries, even if some debonding happens along 1D CNT/alloy interface, it will be less damaging because fracture intrinsically favors 2D percolating flaws. Good intragranular dispersion of these 1D strengtheners is critical for comprehensive enhancement of composite properties, which entails change of wetting properties and encapsulation of CNTs inside Al grains via surface diffusion‐driven cold welding. In situ transmission electron microscopy demonstrates liquid‐like envelopment of CNTs into Al nanoparticles by cold welding.

Feasibility study to control fiber distribution for enhancement of composite properties via three-dimensional printing

ABSTRACTThe distribution of fibers in the composite (which takes into account both their locations and orientations) is one of the important factors that affect the mechanical properties of FRCs. However, this parameter depends on various factors during composite fabrication, and controlling the distribution of fibers in the produced material represents a significant challenge. In this study, the applicability of three-dimensional (3D) printing technique for controlling fiber distributions was evaluated. The fibers fabricated using a 3D printer were placed inside a mold to produce cementitious composites. Three-point bending tests were conducted and the results of the experiment were discussed.

Surface treatment of carbon fibres for interfacial property enhancement in composites via surface deposition of water soluble POSS nanowhiskers

This study reports for the first time the use of water soluble sulfonated octa-phenyl POSS nanowhiskers for the surface treatment for carbon fibres using simple dip-coating method. The water soluble nature of the functionalized POSS makes it appealing from a formulation perspective as it can be applied simply using an aqueous media. The synthesis of the water soluble SOP-POSS was achieved via one-step aromatic electrophilic sulfonation of octaphenyl POSS. Collective results from NMR, XPS and FTIR analysis confirmed the meta mono-substitution of all phenyl rings in the starting material with a sulfonic group, leading to its water solubility. Surface treatment of commercially oxidized and unsized carbon fibres was achieved via simple dip-coating of the fibres in an aqueous media solution containing the synthesized SOP-POSS product. After the dip-coating process, the carbon fibres are homogeneously covered with surface adsorbed SOP-POSS nanowhiskers. Physico-chemical characterization of the fibres investigated by Inverse Gas Chromatography (IGC) revealed an improvement in surface chemical homogeneity associated with a significant increase in surface oxygen contents and an overall level of surface polarity comparable to commercially sized fibres. The interfacial adhesion properties between the treated carbon fibres and an epoxy matrix were investigated by single fibre fragmentation technique. The results of the tests revealed that significant enhancement of interfacial properties was achieved as a result of a combination of physical inter-molecular interactions at the fibre-matrix interface and localized nano-mechanical strengthening of the epoxy. The outcomes of this research lay the path forward for a potential simple surface treatment of commercial carbon fibres for Interfacial property improvement in composites.

Performance Evolution of Alkylation Graphene Oxide Reinforcing High-Density Polyethylene

Alkylated graphene oxide (MGO) was rapidly prepared by a reverse extraction technology in aqueous solution using amphoteric surfactants (LAO). The MGO has an excellent lipophilicity and stability in the air atmosphere. After being incorporated in high-density polyethylene (HDPE) by solution compounding, the HDPE/MGO composites exhibited an obvious enhancement in comprehensive properties of composites, relying on the uniform dispersion and the strong interfacial interaction between MGO and HDPE. The typical and abnormal behaviors of the HDPE/MGO in mechanical and physical properties are systematically analyzed and discussed. Moreover, it is found that the critical intensity ratio of ICH2/IC═C/C–C in Raman spectrum corresponding to the electric percolation threshold of HDPE/MGO is about 1, which is still well established in PP/MGO composites.

Influence of selective reinforcement in dynamic performance of glass-epoxy composites

Polymer composites are in the growing trend of replacing the metallic materials because of their ability toenhance the properties. Property enhancement in composites can be achieved by selective positioning of reinforcement in the matrix and it is termed as selective reinforcement. The reliability of a component in dynamic application depends on the effect of loading parameters. The flexural modulus of glass epoxy composite laminate exposed to dynamic loadingis experimentally investigated. This study isan experimental simulation for a leaf spring application. Two different unidirectional (UD)laminate configurations, 0/R/0/0/0 and 0/0/0/0 are fabricated with and without selective reinforcementby hand lay-up technique. The Taguchi’s DOE and L9 orthogonal array with two loading parameters (frequency and load cycle) are used to plan the experiments. The specimens are exposed to cyclic load using a disc camwith a rise of 6 mm at 2.6 Hz, 4.6 Hz and 8.6 Hz frequencies for 11X103, 22X103 and 33X103 cycles. The flexural modulus of the cyclic loaded laminates is measured by three point bent test (ASTM D 790). Experimental results are statistically analyzed by ANOVA, S/N ratio and Regression analysis. There exists a proportional raise in the flexural modulus of the cyclic loaded laminate and a shift in the effect of the loading parameters on composite flexural modulus attributed to selective reinforcement.

Tensile Properties and Fractographic Analysis of Low Density Polyethylene Composites Reinforced with Chemically Modified Keratin-Based Biofibres

This research has investigated the tensile properties and fractography of animal fibre-reinforced low density polyethylene composites. The composites were synthesized by hot compression moulding using chemically modified white and black cow hair biofibres as the reinforcing phase of composites. Alkaline solutions of varying molarities were used to prepare the chemical treatments in this present study. Tensile properties of the developed composites were evaluated based on molarities of chemical treatment and % fibre loading. Scanning electron microscopy was used to characterize the morphologies of the fractured surfaces of composites. Obtained tensile test results revealed significant enhancement in the tensile properties of composites, with the optimum combination of tensile properties presented by 2 wt% white cow hair biofibre reinforcement treated with 0.15 M sodium hydroxide. Observations from the fractographic analysis of the developed composites revealed shearing of the polymer matrix at the fibre-matrix interface and no fibre pullout behaviour.

Perspectives of Nano‐Carbon Based Engineering Materials

Nano‐carbon materials attained considerable scientific interest due to their unique physico‐chemical properties. Much less reports can be found on transferring the unique properties of super‐strong individual nanoparticles like carbon nanotubes and graphene nanoplatelets into load bearing engineering materials. After reviewing structure and properties of nano‐carbon properties the size effect governing the reduction of inherent mechanical properties upon transfer into macroscopic engineering materials is considered. While the potential of mechanical property enhancement of composites with random orientation of elongated carbon nanoparticles is limited by very low percolation thresholds, manufacturing of aligned microstructures, and tailoring of nanoparticle/matrix interface offers plenty of space for optimizing the mechanical properties of composites subjected to tensile loads. Since compression is the more common loading situation for ultra low‐density nano‐carbon materials the collapse stress is important for deriving design limits of nanoporous carbon materials. At the same level of density materials with nanotube or sheet carbon allotropes forming the struts may be expected to achieve a compression strength orders of magnitude higher than the porous graphitic materials. Finally, economic aspects of nano‐carbon manufacturing are discussed.

Two-fold enhancement in tensile strength of carbon nanotube–carbon fiber hybrid epoxy composites through combination of electrophoretic deposition and alternating electric field

A new carbon nanotube (CNT)–hybridized carbon fiber (CF) was introduced in an attempt to improve interfacial strength between CF and polymeric matrix. Amine-functionalized CNTs was radially deposited on the CF surface through a combination of alternating electric field with electrophoretic deposition process. Radial deposition of CNTs on CF formed a unique porous structure around CF that could significantly increase the interfacial adhesion through interlocking of polymeric matrix. Tensile properties and fatigue life of the reinforced composites were investigated in order to study the effect of interfacial adhesion on mechanical properties of reinforced composites. Results indicate that the radial deposition of CNT on CF can remarkably enhance the compatibility of polymeric matrix with CF. This improvement in compatibility of polymeric matrix with CNT–hybridized CF resulted in considerable enhancement in mechanical properties of composites. The interfacial reinforcing mechanism was explored through fractography of reinforced composites and possible failure modes have been precisely discussed.

Amino acid-functionalized multi-walled carbon nanotubes for improving compatibility with chiral poly(amide-ester-imide) containing l-phenylalanine and l-tyrosine linkages

Amino acid functionalized multi-walled carbon nanotubes (f-MWCNTs)/poly(amide-ester-imide) (PAEI) composites were fabricated by solution mixing method. Proper functionalization and mixing strategy of MWCNTs provides the best opportunity for better distribution and bonding of nanoparticles to the polymer matrix. MWCNTs have been chemically modified with l-phenylalanine to improve their compatibility with l-phenylalanine based PAEI. Field emission scanning electron microscopy micrographs of composite revealed that f-MWCNTs made a good interaction with polymer chains by wrapping the polymer around them, and transmission electron microscopy results confirmed well dispersion with nano size of f-MWCNTs in the polymer matrix. In addition, thermal analysis showed good enhancement in thermal properties of composites compared to pure polymer. Thermal stability of the composites containing f-MWCNTs was enhanced due to their good dispersion and improved interfacial interaction between the amino acid based PAEI matrix and f-MWCNTs.

Effects of block copolymer dispersant and nanotube length on reinforcement of carbon/epoxy composites

The epoxy matrix of a carbon fiber/epoxy composite was modified with multiwall carbon nanotubes (MWCNTs) to improve the matrix dominated thermomechanical properties of the composite. Effects of improved dispersion and nanotube length on reinforcement of the composite were investigated experimentally. The dispersion of the CNTs was enhanced with a block copolymer. Two different CNT lengths, 1 and 10 μm on average, were considered. Irrespective of the length, a pronounced improvement of the composite properties was achieved with 0.5 wt% of MWCNTs with the use of block copolymer. Without the block copolymer, it was found that a higher enhancement of composite properties was achieved with the longer nanotubes.