Increasing the thermal stability and thermal conductivity of polydimethylsiloxane (PDMS) is a crucial issue for thermal applications. This paper focuses on enhancing PDMS's thermal and structural properties by incorporating nanocomposite into the PDMS matrix. An investigation of the impact of rGO-CaCO3 nanocomposite on the thermal and structural properties of PDMS was performed using Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), the thermogravimetric analysis and differential thermal analysis (TGA-DTA), and thermal analyzer tests. It was observed that PDMS doped with rGO-CaCO3 nanocomposite shows better thermal stability, thermal conductivity, and higher crystallinity. The thermal stability was enhanced significantly by adding a 5% rGO-CaCO3 nanocomposite, and the initial and end degradation temperatures rose to 492 degrees C and 605 degrees C, respectively. The thermal conductivity of pure PDMS is approximately 0.17 W/mK, whereas a conductive elastomer filled with 5% rGO-CaCO3 nanocomposite exhibits a thermal conductivity of 0.44 W/mK at a temperature of 20 degrees C. In contrast, the thermal diffusivity is enhanced from 0.13 mm(2)/s to 0.366 mm(2)/s. Additionally, the Fourier Transform Infra-Red (FTIR) spectrum at 1411 cm(-1) becomes sharp and noisy, and an additional peak arises at 1398 cm(-1), corresponding to the vibrational rocking of the C=C bond and C-O-C bond in CaCO3 and rGO.

Current highly integrated devices require heat interface materials with excellent heat conductivity. A simple approach was employed to synthesize thermally conductive and outstanding thermal stability nanocomposite. Calcium carbonate nanoparticles (nano CaCO3) reinforced with reduced graphene oxide (rGO) nanoparticles (rGO/CaCO3) are synthesized using a novel process, and the effect of rGO in CaCO3 structure is examined by Field Emission Scanning Electron Microscope, X-ray diffraction, TGA-DTA, and thermal conductivity. The experimental results show that adding rGO resulted in higher crystallinity and thermal stability. As the wt.% of rGO increases from 1 to 5%, the crystallite size was suppressed by 21.06%, 27.39%, 32.48%, 41.5%, and 45.30%, respectively, compared to the pure nano-CaCO3. Additionally, rGO enhances the thermal conductivity by 35.31% and thermal diffusivity to 1.834 mm2/s by adding 5% rGO.

Natural fiber-reinforced plastics possess several ecological and economic benefits over synthetic polymer composites. However, their sustainability and durability under severe structure loading conditions are of potential concern. The present research work investigates the fatigue behavior and performance of coir filler-reinforced epoxy composites to find its budding commercial applications. Composite samples are fabricated with four different weight percentages of untreated and alkali treated coir filler. Alkaline treatment of coir fillers is carried out with 5 wt% aqueous sodium hydroxide (NaOH) solution to suppress the hydrophobic character of bio-filler sand and improve its mechanical properties. Four different weight percentages of untreated and treated fillers, viz. 2.5, 5, 7.5, and 10%, were selected for sample preparation along with neat polymer samples. Fatigue tests of the samples are carried out up to a maximum of 106 cycles considering the filler content and loading level variation and the corresponding Wohler (S–N) curves are established. An increase in fatigue life and load bearing capacity is observed with an increase in filler loading for untreated samples. However, the alkaline treatment showed a detrimental effect on fatigue life although it improved the load bearing capacity.

In recent years, composite material replaces conventional material like metal, wood etc due to its light weight, high strength to weight ratio and stiffness properties. Natural fibers like coir, bamboo fiber, banana plant fiber etc has low cost, easily availability and less harmful to human. In this work, coir fiber is used as a reinforced material. Composites were prepared with different weight ratio of coir fibers with epoxy resin. To find the effect of coir fibers on the mechanical properties of composite, tensile test, impact test and hardness test were conducted on the prepared specimens. ASTM D638-V and ASTM D256 standards were used to prepare the specimens for tensile and impact test respectively. Experimental result shows that the addition of coir fibers increases the strength of composite; the composite with 7.5% fiber content shows maximum tensile and impact strength. FEA analysis can be done to save time and compare the experimental data with FEA analysis data . Ansys software is used for FEA analysis . Finally check any difference in experimental data with FEA analysis The experimental values are more than the FEA values. Decrease value in mechanical testing may result of the presence of inhomoginites such as, mixture of matrix and reinforced material thoroughly, air bubbles presence in the specimens

The present research aims to assess use of supplementary cementitious materials namely rice husk ash (RHA), cow dung ash (CDA) as partial replacement of cement for low volume concrete road construction. RHA and CDA was prepared by controlled burning using ferro cement furnace. Strength, durability and workability properties for normal and blended concrete were tested to obtain optimum cement replacement proportion with CDA, RHA and CDA–RHA blend. Strength tests included compressive strength, flexural strength, strength activity index; durability tests included ultrasonic pulse velocity test (UPV) and rapid chloride permeability test (RCPT).  The optimum levels of CDA, RHA and CDA–RHA mix blends were obtained by comparing mean compressive and tensile strengths for normal concrete and different levels of replacement of cement with CDA, RHA and CDA–RHA mix blended concrete using ANOVA and t-tests. It could be observed that optimum compressive and flexural strengths could be obtained at 10% replacement level with CDA, 15% with RHA and 10% with CDA–RHA blend in 3:7 ratio. UPV and RCPT results show that blended concrete was durable compared to normal concrete. Blended concrete 15% RHA and 10% CDA–RHA blend was found reduce pavement cost by 4–9% for rural roads. The novelty of the research lies in the analysis provided on blending of such locally available SCMs and the comprehensive cost analysis depicting the usage of such blended concrete for usage in low volume road construction.

In view of fiber orientation problem and seminal ecological economics, the present research work is concentrated on the development of ‘commercial adhesive grade’ epoxy composite reinforced with surface-modified low-cost ‘agronomic waste’- based pineapple leaf (PALF) fillers. To overcome the potential adhesion and moisture absorption issues, surface modification of fillers is accomplished with alkaline treatment. The change occurred in the crystal structure and thermal stability of fillers before and after the treatment is quantified using X-ray diffraction and thermogravimetric analysis. The composite samples are subjected to the tensile test with varying strain rate to investigate its effect on the tensile properties and failure behavior of materials. In addition to this, the plane-strain fracture toughness and flexural test have also been carried out to evaluate the composite properties in bending mode with and without the preexisted crack in materials. The dynamic mechanical analysis has also been conducted from room temperature to 150 °C to evaluate the temperature dependence of mechanical properties. The crystallinity of treated filler has been improved by 8 % due to the loss of non-cellulosic components from filler molecules. The highest value of ultimate tensile strength and Young’s modulus are 22 MPa and 570 MPa, respectively. The maximum values of storage modulus of 10 GPa and glass transition temperature of 91 °C were observed for 2.5 % and 12.5 % of filler content, respectively. From these findings, it is envisaged that the balanced tensile and dynamic mechanical properties of PALF–epoxy composites will elucidate their potential applications.

Natural fibers/fillers based functionally graded composite materials (FGCMs) established as a second generation of composite material that can simultaneously deliver higher level of performance and maintain the ecological balance. In the present work, bamboo filler reinforced thermoset epoxy based functionally graded composite is developed. The three different composite samples are prepared with varying the number of layers (5, 4 and 4) and density of layers. The density of each layer is varied through an incremental addition of 3 wt% of bamboo fillers from top to bottom side. The composite samples are subjected to tensile test at three different crosshead speed of 5, 50, and 500 (in mm/min) to evaluate the effect of crosshead movement speed and number of layers on strength and stiffness. The flexural properties of the specimen are also investigated at constant crosshead speed of 2.13 mm/min. It is observed that the tensile strength decreases but flexural strength increases with the increase in number of layers.

Due to the graded micro-structure and high specific strength-stiffness, bamboo micro fillers are systematically utilized in reinforcing different thermoset and thermoplastic polymers as replacement of conventional glass and carbon fillers. In this work, micro-size bamboo particle fillers are reinforced in ‘specific grade’ thermoset epoxy matrix and its fracture properties has been evaluated by following linear elastic fracture mechanics. To enhance its compatibility with the polymer matrix and to reduce the hydrophilicity, the bamboo micro fillers are surface modified through alkaline treatment. The extent of surface modification and removal of lower weight polymers from filler surface are examined and established by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis and thermogravimetric analysis. The fracture properties of bamboo-epoxy composite material are observed to be increasing with the addition of bamboo fillers and the maximum value of fracture toughness is 0.678 MPa.m 0.5 which is 32% higher than the same for neat epoxy samples. In addition, the mechanisms of notch initiated fracture propagation have also been explained for the understanding of stress singularity present at the preexisted crack tip.

Addressing the growing environmental issues and diverse range of applications, the present work is focused on the development of high potential ‘agro-waste’ such as ‘coir filler’ reinforced epoxy composite and evaluation of its critical mechanical properties under diverse constraints. The produced composite material is subjected to a tensile test with variable strain rate, fracture test, impact test and thermogravimetric analysis to assess its applicability in diverse loading and temperature environment. The experimental results display the complementary effect of coir fillers in improving the mechanical properties of the composite by two to four times as compared to neat epoxy and other bio-fibre/filler based composite materials. The increased tensile and flexural strength with filler addition confirms the evident interaction and load transfer capability of infused coir particle fillers in the epoxy matrix. The rate of crack initiation and propagation in the tensile test seems to be extremely affected by the strain rate variation and at higher crosshead speed, the fracture initiated early due to the singularity existed at the crack tip. The highest value of tensile stress and Young’s modulus for the developed composite material is observed at the crosshead speed of 2 mm/min. The fracture properties is observed to be maximum for 5 wt. % filler loading and the principal mechanism of fracture failure is crack pinning. This study will be able to open new insights and establish the probable application of the low-cost agro-byproduct in the engineered value added bio-based composite material.

The present work is focused to provide an overview of the influence of drilling parameters on thrust force and mechanical properties of biodegradable particleboard composite panels. The usage of particleboard composite material is augmented substantially in the past few decades and many research works focused on the machining of such materials. Among the numerous conventional machining, drilling is the most commonly used procedure for machining of particleboard, whereas milling and turning are less frequently used in particleboard application. The different machining parameters like feed rate, spindle speed, and drill bit diameter/point angle are found to have major influence on the thrust force during drilling operation. In the present work, a detailed review has been presented considering the effect of machining parameters in the drilling of particleboard. In addition, summarized outlines are presented on the surface characteristics of the hole produced in drilling operation and use of optimization techniques such as Taguchi method, which is a response surface methodology to find the optimized delamination factor. The arrangement of maximum spindle speed with low feed rate was established as an optimum arrangement to produce the minimum thrust force during the drilling operation of particleboard composite panels.

The current research work is dedicated to addressing the fibre orientation problem and environmental issues through the development of micron-sized coir particle reinforced epoxy composite with enhanced fracture toughness and viscoelastic properties. A ‘specific grade’ standard epoxy adhesive based polymer composite is produced with reinforcement of surface modified coir particle filler. The surface modification on raw coir filler is carried out by NaOH and confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffractogram and thermogravimetric analysis (TGA). The reduced intensity of hydroxide functional group as well as the enhanced thermal stability of surface modified coir filler is observed by FTIR and TGA respectively. The properties of produced composite samples are investigated by tensile test with low to high strain rate, fracture toughness test and dynamic mechanical analysis. The investigation revealed an improvement in tensile strength, fracture toughness and storage modulus values of toughened coir–epoxy composite with filler loading. The maximum value of ultimate tensile strength, modulus of elasticity and fracture toughness were 27.58 MPa, 0.738 GPa and 1.792 MPa m1/2. The constraints like strain rate and filler content demarcated some critical effects on tensile strength, Young’s modulus and modulus of rupture. The research work suggests the applicability of the developed material as household items, replacement of timber product for indoor and outdoor decorations.

Nowadays, the research and engineering attention stimulated towards development of environmentally gentle materials to satisfy the energy needs of the society through renewable resources. The growing cognizance in the production and consumption of renewable energy for civilization necessities has directed towards the growth in the wind energy utilization. The wind energy is a leading renewable and sustainable energy resource and key answer to the global energy problem. The rotor blades of wind turbines are its integral parts and traditional materials used for blade manufacturing are carbon or glass fibre reinforced polymer composites owing to their low density and high strength to stiffness ratio. But the non renewability and adverse environmental effect during their processing and disposal forced the researchers to look out for some biodegradable and light weight natural plant fibres for reinforcement in polymeric resin to produce required polymer composites. In the present work, application of bio filler based epoxy composite is proposed to be used as wind turbine rotor blades.

To overcome the ecological concern and fiber orientation problem, lignocellulosic wood filler reinforced epoxy composite is developed using ‘micro-size’ particle reinforcement in view of its promising applicability as automobile parts and consumer goods. To identify the phase and functional groups present, the wood microfiller is characterized by Fourier transform infrared spectroscopy and X-ray diffraction analysis. The properties of the developed ‘specific grade’ epoxy composite are investigated in uniaxial tension mode with variable strain rate and in three-point bending mode. The linear elastic fracture mechanics is adopted to find fracture toughness and strain energy release rate at fracture initiation. The dynamic mechanical properties of the produced viscoelastic material are determined over a range of temperature. The investigations demonstrated a noticeable improvement in static and dynamic mechanical properties with the addition of micron size fillers, and properties of this developed material are comparable (or even better) with existing different wood-based composites.

The present state of the art of the bamboo fibres and their reinforcement in polymer matrices is concentrated on bamboo fibre reinforced thermoset and thermoplastic polymer composite material. The bamboo fibre is selected on the basis of sources of origin, growth rate, and availability as agricultural waste, excellent specific mechanical properties and application. An overview of the developments made in the area of bamboo fibre reinforced composites is presented in terms of their mechanical properties, manufacturing procedures and applications. Effect of Fibre orientation, its length, reinforcing concentration, dispersion, aspect ratio, selection and chemistry of matrix and surface modification of fibres on the characteristics of composite has been discussed in resilient manner. Several critical concerns and recommendations for further improvement of composite properties and future work related to bamboo fibres are deliberated. The present work satisfies the need for a short critical review, consolidating the highly utilized agriculture by-products originating from the stem part of the plant fibres.

With the growing apprehension about ecology and economics, the composite materials based on low-cost lignocellulosic biomass have generated a great interest of research. In this paper, a polymer composite has been developed using specific grade epoxy matrix and "particular micron size" bamboo filler and its different mechanical properties have been investigated. The mechanical properties were determined with a variation in different constraints like filler content, strain rate, temperature and chemical treatment to establish the applicability of the developed composite. From the results, it has been found that the static and dynamic mechanical properties of the developed composite are significantly influenced by the different parameters. The scanning electron micrographs demonstrated the even dispersion of particulate fillers in the matrix, agglomeration at higher filler loading and better adhesion due to alkali treatment. Also, the properties are comparable with the existing different bamboo based composite.

In the present era of product development, composites are being used because of the ease in manufacturing and low weight to volume ratio. Moreover apart from the above the increasing awareness towards environmental issues and the requirement of more versatile polymer based materials has led to higher interest in natural fibre/ filler composites, i.e. green composite. In this paper, sundi wood dust reinforced epoxy composites were processed with six different % filler content. The tensile and flexural tests are performed at three different speeds to study the mechanical behaviour of the composites. Experiments were conducted based on Taguchi L18 orthogonal array considering two design parameters viz. speed and % filler wt. The experimental data were analyzed using Taguchi optimization method. Optimal settings of the process parameters for load, tensile and flexural stress were determined. Experimental data obtained were statistically analyzed and the optimized sets of values of the various parameters were depicted. Analysis of variance (ANOVA) analysis was carried out to obtain the significant factors for load, tensile and flexural stress. It was observed from the analysis that speed is the main significant factor affecting the load and tensile stress values but for flexural stress % filler wt. is the main significant factor at 95% confidence level. A confirmation test was carried out to validate the optimized results and it was found that there were improvements in S/N ratios from initial to optimal setting.

In the present era of product development, composites are being used because of the ease in manufacturing and low weight to volume ratio. The increasing awareness towards environmental issues and requirement of more versatile polymer-based materials has led to higher interest in natural fibre/filler composites. In this paper, epoxy composite with six different filler contents (wt%) of sundi wood dust are tested at three different speeds. Tensile and flexural tests are performed according to ASTM standard. Different design parameters i.e., filler content (wt%) and speed for load, tensile stress and flexural stress values are optimised using grey relational analysis (GRA). Entropy method determines the corresponding weights to each criterion. A grey relational grade (GRG) has shown the improved performance parameter, and the best performance is observed at 10 % filler content with speed of 1 mm/min.