Investigations on the performances of treated jute/Kenaf hybrid natural fiber reinforced epoxy composite

Natural fiber composite laminates are nowadays used in structural application such as aerospace, automobile and in sports goods because of their high strength to weight ratio and renewability. Hence the study of mechanical behaviors of natural fiber composites is very important in using these composite laminates for such specific applications. This project aims at identifying the mechanical properties of hybrid natural Jute/Kenaf fiber. The major drawbacks in natural fiber are its Resin incompatibility. Surface treatment of fiber is made to improve the interfacial bonding between the fiber and resin and to reduce the moisture absorption. Laminates are fabricated using Hand lay-up technique. Mechanical properties such as tensile, flexural, and Impact test for jute/kenaf hybrid laminates were obtained. Specimen preparation and Mechanical property testing were carried out as per ASTM standards. Micro structures of the different layer of hybrid specimens are scanned by the Scanning Electron Microscope.     

Long jute fiber‐reinforced polypropylene composite: Effects of jute fiber bundle and glass fiber hybridization

Two types of long jute fiber pellet consisting of twisted‐jute yarn (LFT‐JF/PP) and untwisted‐jute yarn (UT‐JF/PP) pellets are used to prepare jute fiber–reinforced polypropylene (JF/PP) composites. The mechanical properties of both long fiber composites are compared with that of re‐pelletized pellet (RP‐JF/PP) of LFT‐JF/PP pellet, which is re‐compounded by extrusion compounding. High stiffness and high impact strength of JF/PP composites are as a result of using long fiber. However, the longer fiber bundle consequently affects the distribution of jute fiber. The incorporation of 10 wt % glass fibers is found to improve mechanical properties of JF/PP composites. Increasing mechanical properties of hybrid composites is dependent on the type of JF/PP pellets, which directly affect the fiber length and fiber orientation of glass fiber within hybrid composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41819.     

Three‐body abrasive wear behavior of short jute fiber reinforced epoxy composites

In present investigation, the three‐body abrasive wear behavior of short jute fiber reinforced epoxy composites was studied. The effect of various parameters such as fiber loading, sliding velocity, normal load, and abrasive size on the abrasive wear rate of composite has been analyzed. Abrasive wear study has been carried out using a dry sand/rubber wheel abrasion tester. The abrasive wear and friction characteristics of these composites are analyzed successfully using Taguchi orthogonal array and analysis of variance. The experimental study reveals that sliding velocity, fiber loading, and abrasive size have greater influence on the specific wear rate of the composites. The results show that the specific wear rate of the composites decreases with the increase in sliding velocity whereas, with the increase in normal load the specific wear rate increases. The study also revealed that the coefficient of friction of the composites increases up to a certain value than decreases with the increase in normal load as well as sliding velocity. The worn surfaces of the abraded specimens were examined using SEM to understand the mechanism involved in material removal. POLYM. COMPOS., 270–278, 2016. © 2014 Society of Plastics Engineers     

Mechanical and dynamic mechanical properties of jute fibers–Novolac–epoxy composite laminates

A study was done of jute composite using a polymer matrix of epoxidized Novolac resin (ENR), diglycidyl ether of bisphenol A (DGEBA)–based epoxy, and their blends with different weight percentages of the resins. It was found that on blending ENR with DGEBA, the storage modulii at room temperature are enhanced by about 100% or more in the case of 30 and 40% ENR‐containing matrices, whereas the enhancement in the case of 20 and 12% ENR‐containing matrices is only 50% that of the pure matrix. It was also observed that the tan δ peak heights of the composites containing 30 and 40% ENR are closer to that of 20% ENR‐containing composite. The probable explanation drawn on the basis of experimental findings of DMA and mechanical analysis is that by blending ENR with DGEBA epoxy it is possible to manufacture jute composites with increased stiffness without sacrificing their ductility. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2800–2807, 2002     

Moisture absorption behavior and its effect on the mechanical properties of jute‐reinforced epoxy composite

With the growing economic competition and the ecological pressure, the past decade has seen a renewed interest in developing more efficient reinforcements along with overall production cost. In some industrial applications, natural fiber composites fulfill small requirements for making the product to be economical due to their several advantages such as low density, greater deformability, lower abrasiveness, and cost. In the present work, composites are prepared with epoxy as a resin and jute as reinforcement by hand lay‐up technique. Moisture absorption characteristics when exposed to saline water, mineral water, sub‐zero temperature conditions, and also effect of moisture on depreciation in strength (tensile strength and flexural strength) and of different layers (one, two, three layers) of composites are studied experimentally. Specimen preparation and testing were carried out as per ASTM standards. It is found that the jute‐reinforced epoxy composite give encouraging results when compared with the pure epoxy composites. The less effect in strength is observed after exposure to mineral water and sub‐zero temperature condition. The morphologies of the composites are also studied by scanning electron microscope. POLYM. COMPOS., 38:516–522, 2017. © 2015 Society of Plastics Engineers     

Physical and mechanical behavior of unidirectional banana/jute fiber reinforced epoxy based hybrid composites

During the last few years, natural fiber composites are replacing synthetic fiber composites for practical applications due to their advantages like low density, light weight, low cost, biodegradability and high specific mechanical properties. In this connection, the present investigation deals with the fabrication and mechanical properties of unidirectional banana/jute hybrid fiber reinforced composites and compares with the single natural fiber reinforced composites. The physical and mechanical properties of the natural fiber composites were obtained by testing the composite for density, tensile, flexural, inter‐laminar shear, impact, and hardness properties. The composite specimens with different weight percentages of fibers were fabricated by using hand lay‐up technique and testing were carried out as per ASTM standards. Incorporation of both the fibers into epoxy matrix resulted in an increase in mechanical properties up to 30 wt% of fiber loading. It is found that the hybrid composite give encouraging results when compared with the individual fiber composites. The morphologies of the composites are also studied by scanning electron microscope. POLYM. COMPOS., 38:1396–1403, 2017. © 2015 Society of Plastics Engineers     

Preparation and thermo‐mechanical properties of heat‐resistant epoxy/silica hybrid materials

Diglycidyl ether of bisphenol‐A (DGEBA) based epoxy/silica hybrid materials filled with various amounts of 3‐glycidoxypropyltrimethoxysilane (GPTMS) and silica nanoparticles were prepared, using 4,4′‐diaminodiphenyl sulfone (DDS) as curing agent. The obtained hybrid materials were analyzed by means of Fourier‐transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The results indicated that the introduction of GPTMS and silica nanoparticles had synergistic effect. The addition of GPTMS not only ameliorated the compatibility between silica and the epoxy matrix but also increased the crosslinking density of the epoxy system; meanwhile the nano‐silica further reinforced the inorganic network of the hybrid system. Consequently, the hybrid materials showed much improved heat‐resistant properties. The storage modulus of the hybrid systems showed no obvious decrement in the glass transition region and kept at a high value even in the temperature region up to 300°C. The integral thermal stability of the resulting hybrid materials was also improved compared with the corresponding pure epoxy resin. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.     

Characterization of alkali‐treated jute fibers for physical and mechanical properties

Changes occurring in jute fibers when treated with a 5% concentration of a NaOH solution for 0, 2, 4, 6, and 8 h were characterized by weight loss, linear density, tenacity, modulus, FTIR, and X‐ray measurements. A 9.63% weight loss was measured during 2 h of treatment with a drop of hemicellulose content from 22 to 12.90%. The linear density value showed no change until 2 h of treatment followed by a decrease from 33.0 to 14.5 denier by 56% after 6 h of treatment. The tenacity and modulus of the fibers improved by 45 and 79%, respectively, and the percent breaking strain was reduced by 23% after 8 h of treatment. X‐ray diffractograms showed increase in crystallinity of the fibers only after 6 h of treatment, while FTIR measurements showed much of the changes occurring by 2 h of treatment with an increased amount of OH groups. By measuring the rate of change of the modulus, tenacity, and percent breaking strain with the time of treatment, a clear transition was apparent at 4 h of treatment with the dissolution of hemicellulose, causing a weight loss and drop in the linear density before and development of crystallinity with an improvement in the properties after the transition time. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1013–1020, 2001     

The research on the mechanical and tribological properties of carbon fiber and carbon nanotube‐filled PEEK composite

The main objective of this article is to develop high wear resistance carbon fiber reinforced polyether ether ketone composite with addition of multiwall carbon nanotube (MWCNT). These compounds were well mixed in a Haake batch mixer, and compounded polymers were fabricated into sheets of known thickness by compression molding. Samples were tested for wear resistance with respect to different concentration of fillers. The wear resistance properties of these samples depend on filler aspect ratio. Wear resistance of composite with 20 wt% of CF increases when MWCNT was introduced. The worn surface features have been examined using scanning electron microscope. Photomicrographs of the worn surfaces revealed higher wear resistance with the addition of carbon nanotube. Also, better interfacial adhesion between carbon and vinyl ester in carbon‐reinforced vinyl ester composite was observed. POLYM. COMPOS., 31:1315–1320, 2010. © 2009 Society of Plastics Engineers     

Cardanol biocomposites reinforced with jute fiber: Microstructure,biodegradability, and mechanical properties

This work aims at studying the preparation and characterization of composites of phenolic resin (matrix) based on cashew nut shell liquid, reinforced by natural jute fibers. The fibers were chemically modified using alkaline treatment with solutions of NaOH (5 and 10%) and bleached with sodium hypochlorite NaClO/H₂0 (1:1) at 60–75°C. The microstructure was investigated by Scanning Electron Microscopy to observe the fiber surface after the treatment. As a result, there was an improvement in the thermal stability of the fiber, which was verified by Thermogravimetric Analysis. The jute fiber composites showed an improvement in their mechanical properties due to chemical treatment with 5% NaOH. Their biodegradability level depended on the employed alkali solution concentration. This study is important to evaluate the application of the fibers as renewable materials. POLYM. COMPOS., 31:1928–1937, 2010. © 2010 Society of Plastics Engineers.     

Investigation of mechanical properties of alumina nanoparticle‐loaded hybrid glass/carbon‐fiber‐reinforced epoxy composites

This research work investigates the tensile strength and elastic modulus of the alumina nanoparticles, glass fiber, and carbon fiber reinforced epoxy composites. The first type composites were made by adding 1–5 wt % (in the interval of 1%) of alumina to the epoxy matrix, whereas the second and third categories of composites were made by adding 1–5 wt % short glass, carbon fibers to the matrix. A fourth type of composite has also been synthesized by incorporating both alumina particles (2 wt %) and fibers to the epoxy. Results showed that the longitudinal modulus has significantly improved because of the filler additions. Both tensile strength and modulus are further better for hybrid composites consisting both alumina particles and glass fibers or carbon fibers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39749.     

Effect of hyperbranched epoxy resin on mechanical properties of short carbon fiber‐reinforced epoxy composites

Short carbon fiber‐reinforced composites (SCFRCs) have attracted increasing attention owing to their comprehensive performance and easy processing route. However, the imperfect interfacial adhesion and serious stress concentration at the fiber/matrix interface have hampered their engineering application. In this article, we first report the preparation of SCFRC modified by a low‐viscosity liquid hyperbranched epoxy resin (Hyper E102). We then investigated the effect of Hyper E102 content on thermal and mechanical properties. The results show that the overall performance of the SCFRC first increases and then decreases with the increasing content of Hyper E102. With the incorporation of 12 phr Hyper E102, the tensile strength, fracture toughness, notched, and unnotched impact strength of SCFRC were increased by 16.7, 74.9, 95.3, and 194.5%, respectively. The toughening and reinforcing mechanisms were attributed to the following three aspects. First, the Hyper E102 improves the impregnation property of epoxy matrix against fibers, which helps form a better interfacial adhesion. Second, the incorporation of Hyper E102 reduces the internal stress level and stress concentration of the SCFRC. Finally, the critical crack length inside the SCFRC can be remarkably increased with the incorporation of Hyper E102, which can enhance the damage tolerance of a composite. POLYM. COMPOS., 37:2727–2733, 2016. © 2015 Society of Plastics Engineers     

Effect of layering pattern on the physical,mechanical, and thermal properties of jute/bagasse hybrid fiber‐reinforced epoxy novolac composites

In this study, randomly oriented short jute/bagasse hybrid fiber‐reinforced epoxy novolac composites were prepared by keeping the relative volume ratio of jute and bagasse of 1:3 and the total fiber loading 0.40 volume fractions. The effect of jute fiber hybridization and different layering pattern on the physical, mechanical, and thermal properties of jute/bagasse hybrid fiber‐reinforced epoxy novolac composites was investigated. The hybrid fiber‐reinforced composites exhibited fair water absorption and thickness swelling properties. To investigate the effect of layering pattern on thermomechanical behavior of hybrid composites, the storage modulus and loss factor were determined using dynamic mechanical analyzer from 30 to 200°C at a frequency of 1 Hz. The fracture surface morphology of the tensile samples of the hybrid composites was performed by using scanning electron microscopy. The morphological features of the composites were well corroborated with the mechanical properties. Thermogravimetric analysis indicated an increase in thermal stability of pure bagasse composites with the incorporation of jute fibers. The incorporation of hybrid fibers results better improvement in both thermal and dimensional stable compared with the pure bagasse fiber composites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Preparation and properties of successive alkali treated completely biodegradable short jute fiber reinforced PLA composites

The natural fiber reinforced biodegradable polymer composites were prepared with short jute fiber as reinforcement in PLA (Poly lactic acid) matrix. The short jute fiber is successively treated with NaOH at various concentrations (5%, 10%, and 15%) and H₂O₂. The composites were prepared with untreated and treated short jute fibers at different weight proportions (up to 25%) in PLA and investigated for mechanical properties. The results showed that the composite with successive alkali treated jute fiber at 10% NaOH and H₂O₂ with 20% fiber loading has shown 18% higher flexural strength than neat PLA and untreated jute/PLA composite. The flexural modulus of the composite at 25% fiber loading was 125% and 110% higher than that of composites with untreated fibers and neat PLA, respectively. The impact strength of composite with untreated fibers at higher fiber weight fraction was 23% high as compared to neat PLA and 26% high compared to composite with treated fibers. The water absorption was more for untreated jute/PLA composite at 25% fiber loading than all other composites. The composite with untreated fibers has high thermal degradation compared with treated fibers but lower than that of pure PLA matrix. The enzymatic environment has increased the rate of degradation of composites as compared to soil burial. Surface morphology of biodegraded surfaces of the composites were studied using SEM method. POLYM. COMPOS., 37:2160–2170, 2016. © 2015 Society of Plastics Engineers     

Mechanical properties of virgin and recycled polyolefin‐based composite laminates reinforced with jute fabric

Polyolefin‐based composite laminates reinforced with jute fabric were prepared by compression molding and investigated in terms of flexural properties and impact behavior. The use of a virgin polypropylene as the matrix was compared with two polyolefin matrices coming from discarded car bumpers and selected packaging wastes, respectively, and mainly constituted by mixtures of polyethylene and polypropylene resins. The influence of a coupling agent (maleated polypropylene) was always considered in order to improve the interfacial adhesion and, consequently, the composite strength. The effect of this coupling agent, clearly dependent on the amount of polypropylene phase in the overall mixture, was found to be satisfactory only in the case of virgin polypropylene‐based systems. These latter, in presence of maleated polypropylene, have shown higher flexural parameters, lower propagation energy and higher breaking impact load with respect to uncompatibilized ones. Results were supported by morphological observations of impact surfaces, always highlighting a poor adhesion at the reinforcement–matrix interface except in compatibilized virgin polypropylene‐based laminates. POLYM. COMPOS., 36:2022–2029, 2015. © 2014 Society of Plastics Engineer     

Preparation and EMI shielding properties of nickel‐coated PET fiber filled epoxy composites

Electrically conductive composites were prepared using epoxy resin (EP) as matrix and nickel‐coated polyethylene teraphthalate (PET) fibers as filler. The fibers were coated with nickel by plating and ultrasonic electroless deposition techniques. The coaxial transmission line method was used to measure the electromagnetic interference (EMI) shielding effectiveness of the nickel‐coated PET fiber/EP composites. The contents of nickel and phosphorus in the coating were determined by X‐ray photoelectron spectroscopy (XPS). As a result, the ultrasonic electroless nickel‐coated PET fiber/EP composites showed excellent electrical conductive capability and better EMI shielding effectiveness due to higher content of nickel and lower content of phosphorus in the coating than conventional plated nickel‐coated PET fiber/EP composites. POLYM. COMPOS., 27:24–29, 2006. © 2005 Society of Plastics Engineers     

The physical and mechanical properties of polymer composites filled with Fe‐powder

In this study, the effect of Fe powder on the physical and mechanical properties of high density polyethylene (HDPE) was investigated experimentally. HDPE and HDPE containing 5, 10, and 15 vol % Fe metal–polymer composites were prepared with a twin screw extruder and injection molding. After this, fracture surface, the modulus of elasticity, yield and tensile strength, % elongation, Izod impact strength (notched), hardness (Shore D), Vicat softening point, heat deflection temperature (HDT), melt flow index (MFI), and melting temperature (T_m) were determined, for each sample. When the physical and mechanical properties of the composites were compared with the results of unfilled HDPE, it was found that the yield and tensile strength, % elongation, and Izod impact strength of HDPE decreased with the vol % of Fe. As compared with the tensile strength and % elongation of unfilled HDPE, tensile strength and % elongation of 15 vol % Fe filled HDPE were lower, about 17.40% and 94.75% respectively. On the other hand, addition of Fe into HDPE increased the modulus of elasticity, hardness, Vicat softening, MFI, and HDT values, such that 15 vol % Fe increased the modulus of elasticity to about 48%. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Mechanical properties of E‐glass fiber reinforced siliconized epoxy polymer composites

Siliconized epoxy‐matrix systems have been developed by an interpenetrating mechanism using epoxy resins GY 250 and LY 556 (Ciba‐Geigy) and hydroxyl terminated polydimethylsiloxane with γ‐aminopropyltriethoxysilane as crosslinker in the presence of dibutyltindilaurate catalyst. Aliphatic amine (HY 951, Ciba‐Geigy), aromatic amine (HT 972, Ciba‐Geigy) and polyamidoamine (HY 840, Ciba‐Geigy) are used as curing agents for epoxy resins. The tentative level of 10% siloxane introduction into epoxy resin has been ascertained from experimental studies to obtain reasonable improvements in the impact behavior without compromising other mechanical properties. The impact behavior of E‐glass reinforced composites made from the siliconized epoxy resin is enhanced to 2–4 times over that measured on the composites made from a pure epoxy resin. Composites cured with aromatic amine impart better mechanical properties than those cured with aliphatic amine and polyamidoamine.     

Effect of hydrothermal aging on the thermo‐mechanical properties of a composite dental prosthetic material

The aim of this investigation was to evaluate the long‐tern effects of aging in water on the physical properties of a new class of commercially available dental polymer composites. The selected product consists of a bisphenol a glycidyl methacrylate (Bis‐GMA) resin diluted with triethylene glycol dimethacrylate (TEGDMA) and reinforced with long E‐glass fibers, specifically developed for prosthetic dental bridges. Samples were prepared according to a standard procedure suggested by the producer, and aged in water at 37°C and 70°C up to 32 weeks. Samples were periodically tested in order to assess their mass variation, static flexural modulus and strength, fatigue resistance, and dynamic mechanical thermal behavior. Experimental results evidenced that aging caused two simultaneous phenomena, having opposite effects on the specimen mass. In fact, composites absorbed a certain amount of water (up to 0.8 wt% at 37°C and 1.2 wt% at 70°C) but at the same time a mass loss was detected, which could be attributed to a release of unreacted monomeric species and fragments generated by polymer chain degradation (especially at 70°C). Flexural strength strongly decreased during aging in water, reaching 80% and 45% of the initial value for samples aged for 32 weeks at 37 and 70°C, respectively. Aging practically does not affect flxural modulus, while a sensible reduction of the material fatigue life was observed. Glass transition temperature and the relative activation energy were markedly influenced by the aging in water with effects related to the water uptake and mass loss phenomena.     

Effects of a titanate coupling agent on the mechanical and thermo‐physical properties of talc‐reinforced polyethylene compounds

An experimental study was carried out to investigate the effects of a titanate coupling agent on the mechanical properties, moisture absorption, and thermal conductivity of talc‐filled high‐density polyethylene (HDPE). Talc (0–35 wt %) was used as reinforcement particulate filler in an HDPE matrix and samples were prepared in a micro‐compounder and an injection molding machine. Isopropyl tri(dioctyl)phosphate titanate (0.5 wt %) was used as coupling agent. Composites with and without coupling agent were evaluated for changes in mechanical and thermo‐physical properties, morphology, and void content. Addition of the titanate coupling agent most often resulted in an increase in stiffness and tensile strength. Furthermore, both the void content and the elongation at break of composites were reduced. Results also showed that the coupling agent had no effects on the thermal conductivity, thermal diffusivity, and specific heat capacity of the composites. In addition, it was observed that the coupling agent was more effective at low concentrations of filler. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40449.