Influence of filler hybridization on thermomechanical properties of hemp/silver epoxy composite

The polymer composite material’s thermomechanical properties with fiber as reinforcement material have been widely studied in the last few decades. However, these fiber-based polymer composites exhibit problems such as fiber orientation, delamination, fiber defect along the length and bonding are the matter of serious concern in order to improve the thermomechanical properties and obtain isotropic material behavior. In the present investigation filler-based composite material is developed using natural hemp and high thermal conductive silver nanoparticles (SNP) and combination of dual fillers in neat epoxy polymer to investigate the synergetic influence. Among various organic natural fillers hemp filler depicts good crystallinity characteristics, so selected as a biocompatible filler along with SNP conductive filler. For enhancing their thermal conductivity and mechanical properties, hybridization of hemp filler along with silver nanoparticles are conducted. The composites samples are prepared with three different combinations such as sole SNP, sole hemp and hybrid (SNP and hemp) are prepared to understand their solo and hybrid combination. From results it is examined that, chemical treated hemp filler has to maximized its relative properties and showed, 40% weight % of silver nanoparticles composites have highest thermal conductivity 1.00 W/mK followed with hemp filler 0.55 W/mK and hybrid 0.76 W/mK composites at 7.5% of weight fraction and 47.5% of weight fraction respectively. The highest tensile strength is obtained for SNP composite 32.03 MPa and highest young’s modulus is obtained for hybrid composites. Dynamic mechanical analysis is conducted to find their respective storage modulus and glass transition temperature and that, the recorded maximum for SNP composites with 3.23 GPa and 90°C respectively. Scanning electron microscopy examinations clearly illustrated that formation of thermal conductivity chain is significant with nano and micro fillers incorporation.

Download Full-text

STUDYING THE HARDNESS AND THERMAL CONDUCTIVITY OF HYBRID COMPOSITES USING NATURAL ADDITIVES WITH EPOXY

Journal of Engineering and Sustainable Development ◽

10.31272/jeasd.conf.2.2.18 ◽

2021 ◽

Vol 25 (Special) ◽

pp. 2-135-2-145

Author(s):

Hisham A. Chlob ◽

◽

Raad M. Fenjan ◽

Keyword(s):

Thermal Conductivity ◽

Hybrid Composites ◽

Weight Fraction ◽

Short Fiber ◽

Wood Dust ◽

Weight Percentage ◽

Composites Materials ◽

Hardness Tests ◽

American Society ◽

Natural Additives

The goal of the present study is investigating effects of the natural additives from a vegetarian and animal source in a form (short fiber and particles) on hardness and thermal conductivity in composites materials. (jam Wood dust JWD, cow bones CB, date palm fiber DP, as well as sheep wool SW) have been chosen as natural additives with a variety of the reinforcements of weight fraction for epoxy matrix based that have been produced by hand lay-up approach. Thermal conductivity and hardness tests have been conducted based on the American society for the testing and materials (ASTM) for the characterization of hybrid composites it has been discovered that thermal conductivity and hardness may be decreased or increased according to the material additive type, its origin, and weight percentage utilized. %2.5 material (1) + %2.5 material (2), %2.5 material (1) + %5 material (2), %5 material (1) + %2.5 material (2).

Download Full-text

Hybridization effect on Electrical Conductivity and Thermal Behavior of Epoxy/Carbon Nanotubes and Biosynthesized Silver Nanoparticles Composites

10.21203/rs.3.rs-173992/v1 ◽

2021 ◽

Author(s):

Aigbodion Victor Sunday ◽

Solomon Chijioke Madu ◽

Uche Chinweoke Ogbuefi ◽

C.U Nwoji

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotubes ◽

Electrical Conductivity ◽

Silver Nanoparticles ◽

Epoxy Polymer ◽

Electronic Devices ◽

Potential Reduction ◽

Hybridization Effect ◽

Enhanced Thermal Conductivity ◽

Made In

Abstract An attempt was made in this work to decorated carbon nanotubes(CNTs) in a polymer matrix using biosynthesized silver nanoparticles (GAgNPs) using Cashew leaves as a reduction agent. The new hybrid epoxy-CNTs+ GAgNPs composites were produced by modified solution-stir-cast method. The microstructure, thermal properties, strength, and electrical conductivity of the produced composites were determined. The electrical conductivity of the epoxy polymer has been enhanced from 5.6x10-13S/cm to 4.80x10-3S/cm for epoxy-0.5%CNTs and 9.1x10-3S/cm epoxy-0.5%CNTs-0.5%GAgNPs. GAgNPs was effective used to improve the strength of conducting epoxy-CNTs for electronic devices. The addition of CNTs and GAgNPs to epoxy increases the glass transition temperature. It was established that GAgNPs can be promising materials to enhanced thermal conductivity, strength, electrical conductivity of epoxy-CNTs and recover the potential reduction for electronic devices application.

Download Full-text

Mechanical and Thermomechanical Properties of Clay-Cowpea (Vigna Unguiculata Walp.) Husks Polyester Bio-Composite for Building Applications

Applied Sciences ◽

10.3390/app12020713 ◽

2022 ◽

Vol 12 (2) ◽

pp. 713

Author(s):

Esther Nneka Anosike-Francis ◽

Paschal Ateb Ubi ◽

Ifeyinwa Ijeoma Obianyo ◽

Godwin Mong Kalu-Uka ◽

Abdulhakeem Bello ◽

...

Keyword(s):

Hybrid Composite ◽

Morphological Analysis ◽

Hybrid Composites ◽

Unsaturated Polyester ◽

Flexural Modulus ◽

Tensile Modulus ◽

Mechanical Analysis ◽

Thermomechanical Properties ◽

Inhomogeneous Surface ◽

Grey Relational

This study investigates the feasibility of creating a clay polymer-based composite using cowpea husk (CPH) as filler for production of roof tiles. Polymeric composites were fabricated by mixing unsaturated polyester (UPT) resin with cowpea husk at different filler weights and curing. A hybrid composite was produced with the addition of 3 wt.% clay and all samples produced were subjected to flexural, hardness and dynamic mechanical analysis (DMA) tests. The effect of clay addition on the mechanical and thermo-mechanical behaviour of formulated composites was investigated. The morphological analysis of the mono and hybrid system shows a rough and coarse inhomogeneous surface with voids created due to the addition of CPH filler for the mono reinforced and clay uniformly filling the voids that were created by the CPH in the hybrid composite. It is observed that hardness, tensile modulus and flexural modulus of hybrid composites increase with an increase in the CPH contents, while the strength and flexural strength all decrease with filler content. The optimal composition was obtained using Grey relational analysis (GRA) at 18% CPH for both mono and hybrid composite. The results imply that the composite combination can be used in making rooftiles and/or also in applications where low strength is required.

Download Full-text

Effect of weight fraction on the mechanical properties of flax and jute fibers reinforced epoxy hybrid composites

Materials Today Proceedings ◽

10.1016/j.matpr.2020.12.1060 ◽

2021 ◽

Author(s):

N. Karthi ◽

K. Kumaresan ◽

S. Sathish ◽

L. Prabhu ◽

S. Gokulkumar ◽

...

Keyword(s):

Mechanical Properties ◽

Hybrid Composites ◽

Weight Fraction ◽

Jute Fibers

Download Full-text

Preparation and Thermal Conductivity of Epoxy Resin/Graphene-Fe3O4 Composites

Materials ◽

10.3390/ma14082013 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2013

Author(s):

Zhong Wu ◽

Jingyun Chen ◽

Qifeng Li ◽

Da-Hai Xia ◽

Yida Deng ◽

...

Keyword(s):

Magnetic Field ◽

Thermal Conductivity ◽

Thermal Stability ◽

Epoxy Resin ◽

Thermomechanical Properties ◽

Packaging Materials ◽

Mass Ratio ◽

Degree Of Orientation ◽

Ep Matrix ◽

Electrical Insulation Properties

By modifying the bonding of graphene (GR) and Fe3O4, a stable structure of GR-Fe3O4, namely magnetic GR, was obtained. Under the induction of a magnetic field, it can be orientated in an epoxy resin (EP) matrix, thus preparing EP/GR-Fe3O4 composites. The effects of the content of GR and the degree of orientation on the thermal conductivity of the composites were investigated, and the most suitable Fe3O4 load on GR was obtained. When the mass ratio of GR and Fe3O4 was 2:1, the thermal conductivity could be increased by 54.8% compared with that of pure EP. Meanwhile, EP/GR-Fe3O4 composites had a better thermal stability, dynamic thermomechanical properties, and excellent electrical insulation properties, which can meet the requirements of electronic packaging materials.

Download Full-text

Non-Monotonic Sensor Behavior of Carbon Particle-Filled Textile Strain Sensors

Engineering Proceedings ◽

10.3390/i3s2021dresden-10140 ◽

2021 ◽

Vol 6 (1) ◽

pp. 13

Author(s):

Johannes Mersch ◽

Henriette Probst ◽

Andreas Nocke ◽

Chokri Cherif ◽

Gerald Gerlach

Keyword(s):

Thermoplastic Polyurethane ◽

Carbon Particle ◽

Equivalent Circuit Model ◽

Conductive Filler ◽

Underlying Mechanism ◽

Human Motion ◽

Strain Sensors ◽

Material Behavior ◽

Strain History ◽

Filled Elastomers

Carbon particle-filled elastomers are a widely researched option to be used as piezoresistive strain sensors for soft robotics or human motion monitoring. Therefore, various polymers can be compounded with carbon black (CB), carbon nanotubes (CNT) or graphene. However, in many studies, the electrical resistance strain response of the carbon particle-filled elastomers is non-monotonic in dynamic evaluation scenarios. The non-monotonic material behavior is also called shoulder phenomenon or secondary peak. Until today, the underlying cause is not sufficiently well understood. In this study, several influencing test parameters on the shoulder phenomena are explored, such as strain level, strain rate and strain history. Moreover, material parameters such as CNT content and anisotropy are varied in melt-spun CNT filled thermoplastic polyurethane (TPU) filament yarns, and their non-monotonic sensor response is evaluated. Additionally, a theoretical concept for the underlying mechanism and thereupon-based model is presented. An equivalent circuit model is used, which incorporates the visco-elastic properties and the characteristic of the percolation network formed by the conductive filler material. The simulation results are in good agreement when compared to the experimental results.

Download Full-text

Synthesis, Characterization and Testing of Antimicrobial Activity of Composites of Unsaturated Polyester Resins with Wood Flour and Silver Nanoparticles

Materials ◽

10.3390/ma14051122 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1122

Author(s):

Przemysław Pączkowski ◽

Andrzej Puszka ◽

Malgorzata Miazga-Karska ◽

Grażyna Ginalska ◽

Barbara Gawdzik

Keyword(s):

Silver Nanoparticles ◽

Staphylococcus Epidermidis ◽

Polyester Resin ◽

Wood Flour ◽

Unsaturated Polyester ◽

Thermomechanical Properties ◽

Resin Composites ◽

Polyester Resins ◽

Before And After

This paper presents the properties of the wood-resin composites. For improving their antibacterial character, silver nanoparticles were incorporated into their structures. The properties of the obtained materials were analyzed in vitro for their anti-biofilm potency in contact with aerobic Gram-positive Staphylococcus aureus and Staphylococcus epidermidis; and aerobic Gram-negative Escherichia coli and Pseudomonas aeruginosa. These pathogens are responsible for various infections, including those associated with healthcare. The effect of silver nanoparticles incorporation on mechanical and thermomechanical properties as well as gloss were investigated for the samples of composites before and after accelerating aging tests. The results show that bacteria can colonize in various wrinkles and cracks on the composites with wood flour but also the surface of the cross-linked unsaturated polyester resin. The addition of nanosilver causes the death of bacteria. It also positively influences mechanical and thermomechanical properties as well as gloss of the resin.

Download Full-text

Processing of high weight fraction banana fiber reinforced epoxy composites using pressure induced dip casting method

Journal of Composite Materials ◽

10.1177/0021998320988044 ◽

2021 ◽

pp. 002199832098804

Author(s):

TP Mohan ◽

K Kanny

Keyword(s):

Matrix Composite ◽

Epoxy Polymer ◽

Epoxy Composite ◽

Matrix Material ◽

Natural Fibers ◽

Weight Fraction ◽

Polymer Composite Material ◽

Fiber Reinforced ◽

Banana Fiber ◽

Banana Fibers

The objective of this work is to realize new polymer composite material containing high amount of natural fibers as a bio-based reinforcement phase. Short banana fiber is chosen as a reinforcement material and epoxy polymer as a matrix material. About 77 wt.% of banana fibers were reinforced in the epoxy polymer matrix composite, using pressure induced fiber dipping method. Nanoclay particles were infused into the banana fibers to improve the fiber matrix interface properties. The nanoclay infused banana fiber were used to reinforce epoxy composite and its properties were compared with untreated banana fiber reinforced epoxy composite and banana fiber reinforced epoxy filled with nanoclay matrix composite. The surface characteristics of these composites were examined by electron microscope and the result shows well dispersed fibers in epoxy matrix. Thermal (thermogravimetry analysis and dynamic mechanical analysis), mechanical (tensile and fiber pullout) and water barrier properties of these composites were examined and the result showed that the nanoclay infused banana fiber reinforced epoxy composite shows better and improved properties. Improved surface finish composite was also obtained by this processing technique.

Download Full-text

Improving the Actuation Speed and Multi-Cyclic Actuation Characteristics of Silicone/Ethanol Soft Actuators

Actuators ◽

10.3390/act9030062 ◽

2020 ◽

Vol 9 (3) ◽

pp. 62 ◽

Cited By ~ 1

Author(s):

Boxi Xia ◽

Aslan Miriyev ◽

Cesar Trujillo ◽

Neil Chen ◽

Mark Cartolano ◽

...

Keyword(s):

Thermal Conductivity ◽

Short Term Memory ◽

Conductive Filler ◽

Thermally Driven ◽

Thermally Conductive ◽

Ethanol Evaporation ◽

Long Short Term Memory ◽

Soft Actuators ◽

Robotic Applications ◽

Soft Composite

The actuation of silicone/ethanol soft composite material-actuators is based on the phase change of ethanol upon heating, followed by the expansion of the whole composite, exhibiting high actuation stress and strain. However, the low thermal conductivity of silicone rubber hinders uniform heating throughout the material, creating overheated damaged areas in the silicone matrix and accelerating ethanol evaporation. This limits the actuation speed and the total number of operation cycles of these thermally-driven soft actuators. In this paper, we showed that adding 8 wt.% of diamond nanoparticle-based thermally conductive filler increases the thermal conductivity (from 0.190 W/mK to 0.212 W/mK), actuation speed and amount of operation cycles of silicone/ethanol actuators, while not affecting the mechanical properties. We performed multi-cyclic actuation tests and showed that the faster and longer operation of 8 wt.% filler material-actuators allows collecting enough reliable data for computational methods to model further actuation behavior. We successfully implemented a long short-term memory (LSTM) neural network model to predict the actuation force exerted in a uniform multi-cyclic actuation experiment. This work paves the way for a broader implementation of soft thermally-driven actuators in various robotic applications.

Download Full-text