The composite materials are very advent gable over conventional materials because of theirdifferent character like higher specific strength, stiffness and fatigue by which structural design to be more versatile. Composite materials consist of two or more constituents but different physically separable phases[(Krobjilowski, 33(2), 2003)].But when the composites phase material hasdifferent physical propertiesthen it is recognised as being a composites material.Composites are consists a strong load carrying material(reinforcement) which is embedded in weak material (matrix).The strength and rigidity provides by reinforced material to support the structural load whereas matrixor binder provides the position andorientation of the reinforcement.The constituents of the composites show their individualphysical and chemical properties until themtogetherely produce a combination of qualities which is impossible to produced by aindividual constituent.The reinforcement materials are plateletsor particles orfibres and they are mainly added to improve mechanical properties such as strength, stiffnessand toughness of the matrix material.
This is to certify that the thesis entitled “FABRICATION AND CHARACTERIZATION OF RAW AND DEWAXED COIR FIBER REINFORCEDPOLYMERCOMPOSITES” submitted by Miss. RINKI CHOUDHURY, Roll No. 410PH2122 in partial fulfillment of the requirements for the award of Master’s degree in Physics at the National Institute of Technology, Rourkela (Deemed University) is an authentic work carried out by her under my supervision and guidance. To the best of my knowledge and believe, the matter embodied in the present thesis has not been submitted to any other University/ Institute for the award of any Degree or Diploma.
dominant role in many industrial applications. Major OMEs such as Airbus and Boeing have shown the potential for large-scale composite application in aviation, and NASA is continually looking to composite manufacturers for innovative space solutions for rocket and other spacecraft. In this point of view, the objective of our present work is to analyze the effect of hybrid fibers (glass fiber and jute fiber) on mechanical behavior of epoxy resin based composite. Different types of composites are fabricated by using hand layup method
Composite materials are widely used in aerospace, aircraft, automotive, nuclear applications, defense industry and sporting goods due to their superior properties such as high strength, wear, fatigue and corrosion resistance, toughness, high-temperature performance, lightness and aesthetic appearance. Composite materials consist of the mixture of two or more elements to combine their superior properties in a single material. They are classified as metal, ceramic and polymer matrix composites according to matrix materials [4-7].
consisting of Pati bet also known as murta (Clinogyne dichotoma) reinforcement, unsaturated polyester resin (UPR) matrix and talc filler were fabricated by simple cold press molding. Thermosetting unsaturated polyester resin with 7.5% styrene monomer was used as matrix which form gel in 2-3 hours by using 1.5% methyl ethyl ketone peroxide (MEKP) hardener. Double layer woven fibre mats were used. Talc was used as at different weight percentages (5%, 10% an d 15%) to investigate its effects on different properties of composites. It was observed that flexural strength and modulus increased with an increase in talc content. Thermal stabilities of composites were also improved.
A review on investigation, characterization and applications for natural fiber reinforcedpolymer hybrid composite is presented in this literature work. The usage of natural fiber as reinforcement in polymercomposites was made a brief study of natural fibers. The fabrication of natural fiber with and without adding the filler or particulate material with different fillers and properties will change in the natural fiber based polymer composite. Comparing natural fiber and glass fiber reinforcedcomposites found that natural fibers is having more advantages but the strength of the natural fibers is low as compare to the manmade fibers. The NFRPC’s have been proven alternative to SFRPC’s in many applications in transportation, construction and packaging industries. Ongoing researches find varieties of natural fibers, which improve the mechanical strength of polymercomposites. From the comparative study Natural fibers and particle fiber composite results in lighter properties compared to SFRPC’s with equal mechanical strength. The Production of natural fiber is more labor intensive and hence NFRPC industry will create new employment and increases the economy Moreover, due to the usage of natural fibers in different engineering, automobile application and construction industries and it gives the way for economic development in rural areas. The results in the investigation tells that, there is a possibility to extend the work in natural fibers like hemp, abaca, flax and other natural fiber reinforcedpolymercomposites. But very few investigations carried on hemp and flax as studied by the literature review. The new Development of hybrid composites with suitable applications in automobile industry is for weight and cost reduction, this leads way for the investigation on mechanical properties of hemp fiber reinforced epoxy hybrid composites by investigating with adding the filler materials to the naturalcomposites and tries to match to the suitable application in engineering and automobile applications. The Applications of NFC’s have extended dramatically including engineering Applications like load bearing and outdoor applications such as automotive interior & exterior under floor paneling, sports equipment and marine applications. Further research is still required to extend their application range to a higher level in the aircraft design, interior design in automobiles
ABSTRACT:Composite materials placed a predominant role in many of the conventional materials. Fibrereinforced plastics have gained recognition as structural material. Reinforcement with naturalfibre in composites has recently gained attention due to low cost, easy availability, low density, easy of separation, biodegradability, and recyclable in nature. Fibrereinforced plastics can replace steel in chemical, marine and transport industries. The present work describes the development and characterization of mechanical properties of naturalfibre based polymercomposites consists of Cordia Dichotoma as reinforcement and Epoxy resin as matrix. Experiments carried out to develop the composites and different weight fraction naturalfibre. The fabrication is done by Hand lay-up technique with the extracts of the naturalfibre and the matrix material. The laminates was done by using different Fibre-Epoxy weight ratio.
fiber loading. Isocyanine-, silane-, acrylated, latex coated and peroxide-treated composite withstood tensile stress to higher strain level.Isocyanate treated, silane treated, acrylated, acetylated and latex coated composites showed yielding and high extensibility. Tensile modulus of the composites at 2% elongation showed slight enhancement upon mercerization and permanganate treatment. The elongation at break of the composites with chemically modified fiber was attributed to the changes in the chemical structure and bondability of the fiber. Alkali treated (5%) sisal-polyester biocomposite showed about 22% increase in tensile strength. Ichazo et al. found that adding silane treated wood flour to PP produced a sustained increase in the tensile modulus and tensile strength of the composite. Joseph and Thomas studied the effect of chemical treatment on the tensile and dynamic mechanical properties of short sisal fiberreinforced low density polyethylene composites. It was observed that the CTDIC (cardanol derivative of toluene diisocyanate) treatment reduced the hydrophilic nature of the sisal fiber and enhanced the tensile properties of the sisal-LDPE composites. They found that peroxide and permanganate treated fiber-reinforcedcomposites showed an enhancement in tensile properties. They concluded that with a suitable fiber surface treatment, the mechanical properties and dimensional stability of sisal-LDPE composites could be improved. Mohanty et al. studied the influence of different surface modifications of jute on the performance of the biocomposites. More than a 40% improvement in the tensile strength occurred as a result of reinforcement with alkali treated jute. Jute fiber content also affected the biocomposite performance and about 30% by weight of jute showed optimum properties of the biocomposites.
Abstract: Last few decades have seen fibrereinforced composite materials being used predominantly in various applications. This review paper discusses about the flexural properties of banana fibre with bio-fibres, which are reinforced hybrid polymercomposites. Banana fiber is a lingo-cellulosic fiber, which is obtained from the pseudo-stem of banana plant. Banana fibre is the best fibre with relatively good mechanical properties. Banana fiber has good specific strength properties comparable to those of conventional material, like glass fiber. This material has a lower density than glass fibers. Flexural strength of reinforced composite materials is an important factor in the manufacturing of aircraft structures and woven or braided composites. These are used for a wide variety of cross-sectional forms such as stiffeners, truss members, rotor blade, automobile body parts, spares, etc. and they reduce the fabrication cost and weight. A composite material is made by combining two or more materials of banana fibre or bio-fibres with suitable binders or resin. Reinforcement with naturalfibre in composites has recently gained attention due to low cost, low density, eco-friendliness, acceptable specific properties, ease of separation, enhanced energy recovery, Co 2 neutrality, biodegradability and recyclable nature.
To fabricate the single fibre pull out specimens, both ends of the selected ﬁbres (treated with 3, 6 and 9 wt% NaOH) were adhered to two pieces of rubber to hold the ends of the ﬁbres and also to prevent the resin from leaking during curing process. All the specimens were ﬁxed to a gauge length of 10 mm. The gauge length was set to be short because longer ﬁbres tend to have a higher possibility of ﬂaws, which affects the consistency of results. Figure 3.1a shows the single fibre pull out sample preparation before pouring the resin mixture into the metal mould (90 mm × 10 mm × 10 mm). Before proceeding to specimen fabrication, a non-stick paper was placed into the mould to prevent the mixture from sticking and to ensure it was easy to remove after the curing process. The epoxy resin was mixed with hardener in a ratio of 3:1. The mixture was left for approximately five to 10 minutes and then poured carefully into the mould to avoid generating bubbles in the sample. Next, the mixture was poured into the mould and left to be cured at room temperature for 24 hours. Later, the sample was removed from the mould, as seen in Figure 3.1b. Finally, the composite was cut to desired ﬁbre embedment lengths of 5, 10, 15 and 20 mm using a hand saw.
Abstract— The main objective of this thesis is to fabricate and investigate mechanical properties of sisal naturalfibrereinforcedpolymer composite and hybrid (sisal + jute + okra) naturalfibrereinforcedpolymer composite. Hybrid composite is fabricated by adding 35% of sisal, 35% of jute and 30% of okra fibre. Mechanical properties such as Tensile properties (tensile strength, tensile modulus), Flexural properties (Flexural strength, Flexural modulus), Impact strength when subjected to varying weights of fibre (0.4, 0.8, 1.2, 1.6, 2 grams) were determined.
It is such an effort to use the natural fibers as the reinforcement for polymercomposites because of its hydrophilic characteristic made them poor incompatibility in adhesion with hydrophobic matrix and leading to nonuniform dispersion of fibres within the matrix. This is a major disadvantage of naturalfibrereinforced composite (Wong, Yousif & Low, 2010).
Environment pollution being caused by plastic waste has threatened the delicate atmosphere in several developing countries. However only a few countries have worked on such reasonably tricky issues of waste management and reducing environment pollution .Republic of India was troublesome in financing such amounts of cash and infrastructure over alternative solutions that are required. During this work an attempt is created for fabrication of such chemical compound composites like naturalfibre reinforcing which is way favorable substitute. For such non-biodegradable plastics which are employed in reinforcing and creating composite largely ecofriendly. Additional demanding environmental laws are encouraging researchers to design composites with the smallest amount environmental footprint which might be used for the domestic and industrial purpose. Green, ecologically (environmentally) friendly, sustainable, renewable and perishable composites from plant derived fibre and derived plastics are among the foremost keenly needed materials of the 21st century. Biobased composites possess a large vary of end of life prospects like incineration, recovery/recycling and composting. Research on this field drew attention because of the following parameters of jute. Research on biodegradable polymercomposites, containing lingo cellulosic fibres, generates attention due to the dwindling
Abstract:- Nowadays, due to environment concern and financial problems of synthetic fibres, bio-fibres are interesting to be used for many structural and construction materials. Natural fibres as reinforcement in polymer composite for making low-cost materials are growing day by day. Researcher’s main attention is to apply appropriate technology to utilize these natural fibres as effectively and economically as possible to produce good quality fibre-reinforcedpolymercomposites for various engineering applications .The combination of Aloe Vera and Ramie fibre may have better tensile strength and Flexural strength .The aim of this study is to evaluate mechanical properties such as tensile and flexural properties of these natural fibres. The composite is manufactured by hand-lay process method and it has five layers. Mechanical characteristics are compared with existing materials and used for structural and non-structural application as a product. Glass fibres are used to laminate the composites on the top and bottom because it increases the surface finish and increases the strength.
influence of chemical treatment on natural fibres reinforcing polymercomposites. The study focused naturalfibre reinforcing polyester composites, In the experiment fibres has been treated with NaOH, Alfa “grass” fibre has been used to determine the chemical influence. The fibre samples were subjected to 1%, 5% and 10% of NAOH for a period of 0-24-48 hours at 28c⁰, to determine the best conditions of the sample treatment. The experiment result indicated that NAOH treatment increases the fibre/matrix interface. Sample treatment with 10% NAOH in 24 hours had the best flexural properties. However after 48 hours the fibre sample will be more brittle and stiffer. Furthermore Mulinari et al. (2011) has published a similar study in the same area which ensure that alkali “NAOH” treatment improves the naturalfibre mechanical properties to reinforce polymers. In the experimental study “mechanical properties of coconut fibres reinforced polyester composites” Fatigue and tensile test has been conducted to determine the mechanical properties of the naturalfibre samples after the chemical treatment. On the other hand, Reis (2012a) claims that chemical treatment have not affect the fibre fracture behaviour or lead to any significant improvement, after conducting an experimental study on sisal fibre reinforce epoxy. In spite of the fact that fibre surface treatment supposed to improve the fibrepolymer composite adhesion however in this case it was not determined.
The attractive physical and mechanical properties that can be obtained with bamboo fiber reinforcedcomposites, such as high specific modulus, strength and thermal stability, have been well documented in the literature. Jain et al.  have compared the Bamboo fiber reinforced epoxy composites (BFRP) epoxy with Bamboo fiber reinforced unsaturated polyester composites (BFRP) USP in terms of their cost and mechanical strength. Cost of unsaturated polyester (USP) was found to be only 20% to that of the epoxy resin, whereas the mechanical properties of these two composite were comparable. Thus giving an edge to the USP based composites. BFRP composites have shown more elongation and 10% high tensile strength. These composites can be used for a variety of commercial application such as crash helmet, low cost housing and wind mills. Kumar et al.  have studied the effect of coating bamboo fibers with Polyurethane (PU) and Polyurethane/Polystyrene Interpenetrating Network (PU/PSIPN) on tensile property of the composites. Both the untreated / alkali treated bamboo fibers were coated with polyethylene glycol based PU and its semi inter penetrating network (SIPN) with PS. It was found that tensile strength of bamboo has increased after coating with PU and PU/PS system. PU/PS coating on alkali treated bamboo fibers has shown a rise (74%) in the tensile load at break than PU (11%) coating on alkali treated fiber. Lee et al.  have fabricated bio-composites of poly (lactic acid) (PLA)/bamboo fiber (BF) and poly (butylene succinate) (PBS)/bamboo fiber (BF).They have investigated effect of lysine based diisocynate (LDI) as coupling agent On properties of bio composites .They have reported that tensile properties and water resistance were improved by addition of LDI. These improvements were due to enhanced interfacial adhesion between polymer matrix and bamboo fiber. Results of enzymatic degradation showed that biodegradability could be adjusted by controlling degree of interfacial adhesion using LDI. They have observed that these bio-composites are beneficial in areas where biocompatibility and environmentally responsible design and construction are required.
Woven fabric E- glass fibre were cut into the size of 25 cm X 20 cm to form 16 layer sheets (laminates) and weighed. LY-556 epoxy resins based on Bisphenol A is weighed to be 40% of the total weight of the fibre and epoxy resin. For fabrication of glass/epoxy (weight fraction of glass fibre is 60%) and of carbon/epoxy (weight fraction of glass fibre is 60%). Then, Hardener HY 951 (aliphatic primary amine) at the ratio of 10% by weight of epoxy resin was used. Glass fibre/epoxy and carbon fibre/epoxy composite laminate have been prepared by hand lay-up method and cured in a hydraulic press by compression moulding method at 55° C temperature and 20 kg/cm 2 pressure for 20 minutes. Now, the cured laminates were cut with the help of diamond cutter as per the ASTM-2344 standard dimensions for short beam shear (SBS) test specimens. The specimens were dried in oven at 60° C for 12 hours at a regular interval of 2 hours to remove moisture and volatile substances. In-situ short beam shear (SBS) tests of glass/epoxy specimens were carried out with the help of INSTRON 5967 ( Servo hydraulic machine with 30 KN load cell) at ambient, -20°C, - 40°C and -60°C temperature at 1, 10, 100, 300, 600,1000 mm/min loading rate. Fractographic analysis was carried out using scanning electron microscope (JEOL-JSM 6480 LV SEM) of ambient and low temperature treated samples in back scattered electron mode. The TMDSC( Temperature modulated differential scanning calorimetry) were done by Mettler-Toledo 821 and analysis of ambient and low temperature treated specimens were carried out at a temperature range of 25°C-120°C at a heating rate of 10°C/min. Then, the FTIR (Fourier transform infrared spectroscopy) imaging was performed in AIM-800 Automatic Infra red Microscope (SHIMADZU).
Flexural fatigue behavior of Poly-propylene fibrereinforcedpolymer concrete composites (PFRPCC) has been investigated at various stress levels and the statistical analysis of the data thus obtained has been carried out. Polymer Concrete Composite (PCC) samples without addition of any type of fibres were also tested for flexural fatigue. Forty specimens of PCC and One hundred and Forty One specimens of PFRPCC containing 0.5%, 1.0% and 2.0% polypropylene fibres were tested in fatigue using a MTS servo controlled test system. Fatigue life distributions of PCC as well as PFRPCC are observed to approximately follow a two parameter Weibull distribution with correlation coefficient exceeding 0.9. The parameters of the Weibull distribution have been obtained by various methods. Failure probability, which is an important parameter in the fatigue design of materials, has been used to obtain the design fatigue lives for the material. Comparison of design fatigue life of PCC and PFRPCC has been carried out and it is observed that addition of fibres enhances the design fatigue life of PCC.
Abstract—Unidirectional carbon/epoxy composite laminates are highly orthotropic, with their conductivity and permittivity being strongly dependent on the incident angle relative to the fibre orientation. This paper presents a novel frequency selective polarizing subreflector manufactured from unidirectional carbon fibrereinforcedpolymer (CFRP), placed a certain distance from a conducting ground also made from CFRP laminate. Theoretical analysis, computational simulation, and experimental measurements are conducted to investigate the effects of separation offset, laminate thickness and incident angle on the performance of a reflector manufactured from a unidirectional IM7/977-3 CFRP. The results show that this new reflector reduces the cross polarization at S-band by 13 dB while remaining a good reflector at X-band and the incident angle has minimal effect on the frequency response of the polarizer. The single reflector can support two orthogonal polarized frequencies, unlike traditional wire grid polarizer screens.
Fibres can also be treated by acetylation to enhance the fibre properties and improve the durability. Acetylation of natural fibres has not been studied to the same extent as alkaline treatment. The main purpose of acetylation is to graft acetyl groups (CH 3 COO - ) on the fibre cell wall and remove surface impurities. During acetylation, Acetic Acid (CH 3 COOH) is generated as a by-product and should be removed before the fibre is used (Li et al., 2007). Acetylation stabilises the cell wall, improves dimensional stability and decelerates environmental degradation. During acetylation the hydroxyl groups of the cell wall are replaced with acetyl groups (CH 3 COO - ). This process is also called grafting (Kalia et al., 2009). The voids in the cell wall are filled and better fibre-matrix interaction is achieved (Kabir et al., 2012). Acetylation also reduces the hydrophilic nature of vegetable fibres by removing hemicellulose and lignin from the fibre, which means that the ability of the fibre to absorb water is reduced. In the case where water is absorbed, no additional swelling of the fibre will take place (Mwaikambo & Ansell, 1999). Martins et al., (2004) found that acetylation exposes the fibrils leading to a rougher surface texture.