Physico-Mechanical and Degradation Properties of Gamma-Irradiated Biocomposites of Jute Fabric-Reinforced Poly(caprolactone)

Jute fabric-reinforced poly(caprolactone) biocomposites (30–70% jute) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength of the non-irradiated composites (50% jute) were found to be 65 MPa, 0.75 GPa, 75 MPa, 4.2 GPa and 6.8 kJ/m², respectively. The composites were irradiated with gamma radiation at different doses (50–1000 krad) at a dose rate of 232 krad/hr and mechanical properties were investigated. The irradiated composites containing 50% jute showed improved physico-mechanical properties. The degradation properties of the composites were observed. The morphology was evaluated by scanning electron microscope.     

Fabrication and Mechanical Characterization of Jute Fabrics: Reinforced Polyvinyl Chloride/Polypropylene Hybrid Composites

Jute fabrics such as reinforced polyvinyl chloride (PVC), polypropylene (PP), and a mixture of PVC and PP matrices-based composites (50 wt% fiber) were prepared by compression molding. Tensile strength (TS), bending strength (BS), tensile modulus (TM), and vbending modulus (BM) of jute fabrics' reinforced PVC composite (50 wt% fiber) were found to be 45 MPa, 52 MPa, 0.8 GPa, and 1.1 GPa, respectively. The effect of incorporation of PP on the mechanical properties of jute fabrics' reinforced PVC composites was studied. It was found that the mixture of 60% PP and 40% PVC matrices based composite showed the best performance. TS, BS, TM, and BM for this composite were found to be 65 MPa, 70 MPa, 1.42 GPa, and 1.8 GPa, respectively. Degradation tests of the composites for up to six months were performed in a soil medium. Thermo-mechanical properties of the composites were also studied.     

The Preparation and Characterization of Silk/Gelatin Biocomposites

There is a growing interest in the use of composite materials. Silk fiber/gelatin biocomposites were fabricated using compression molding. The fiber content in the composite varied from 10–30 wt%. Composite containing 30 wt% silk showed the best mechanical properties. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength, hardness of the 30% silk content composites were found 54 MPa, 0.95 GPa, 75 MPa and 0.43 GPa and 5.4 kJ/m², 95.5 Shore A, respectively. Water uptake properties at room temperature, accelerated weathering aging, irradiation, thermomechanical analysis, and degradation in soil were carried out in this experiment.     

Jute Reinforced Polymer Composite by Gamma Radiation: Effect of Surface Treatment with UV Radiation

Jute (Hessian cloth) reinforced polymer composites were prepared with a mixture of 2-hydroxy ethyl methacrylate (HEMA) and aliphatic urethane diacrylate oligomer (EB-204), and then cured under gamma radiation. Thick pure polymer films (2 mm thickness) were prepared by using the same monomer and oligomer at different weight ratios, and 500 krad of total gamma radiation dose at 600 krad/hr was selected for the curing of all composites. Total radiation dose, jute content, and monomer concentration were optimized with the extent of mechanical properties. Among all resulting composites, the composite of 38% jute content at monomer:oligomer = 50:50 (w/w) ratios showed the better mechanical properties, such as 108% increase in tensile strength (TS), 58% increase in bending strength (BS), 138% increase in tensile modulus (TM), and 211% increase in bending modulus (BM) relative to pure polymer film. The gel content values were also found to increase with the increase of jute content in the composite. But the elongation at break (Eb) for both tensile and bending was found to decrease with increasing jute content. The best mechanical properties were obtained when jute fibers were pre-irradiated with UV radiation, such as 150% increase in TS, 90% increase in BS relative to polymer film, 19% increase in TS, and 15% increase in BS relative to untreated jute-based composites. A water uptake behavior investigation of the resulting composites was also performed and composites based on UV-treated jute showed the minimum water uptake value.     

Comparative Studies of Mechanical and Interfacial Properties Between Jute Fiber/PVC and E-Glass Fiber/PVC Composites

Composites (50 wt% fiber) of jute fiber reinforced polyvinyl chloride (PVC) matrix and E-glass fiber reinforced PVC matrix were prepared by compression molding. Mechanical properties such as tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS) of both types of composites was evaluated and compared. Values of TS, TM, BS, BM and IS of jute fiber/PVC composites were found to be 45 MPa, 802 MPa, 46 MPa, 850 MPa and 24 kJ/m², respectively. It was observed that TS, TM, BS, BM and IS of E-glass fiber/PVC composites were found to increase by 44, 80, 47, 92 and 37.5%, respectively. Thermal properties of the composites were also carried out, which revealed that thermal stability of E-glass fiber/PVC system was higher. The interfacial adhesion between the fibers (jute and E-glass) and matrix was studied by means of critical fiber length and interfacial shear strength that were measured by single fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were investigated by Scanning Electron Microscopy.     

Effect of Ultraviolet Radiation on the Mechanical and Dielectric Properties of Hessian Cloth/PP Composites with Starch

Hessian cloth (jute fabrics) reinforced poly(propylene) (PP) composites (45 wt% fiber) were prepared by compression molding and the mechanical properties were evaluated. Jute fabrics and PP sheets were treated with UV radiation at different intensities and then composites were fabricated. It was found that mechanical properties of the irradiated jute and irradiated PP-based composites were found to increase significantly compared to that of the untreated counterparts. Irradiated jute fabrics were also treated with aqueous starch solution (1–5%, w/w) for 2–10 min. Composites made of 3% starch-treated jute fabrics (5 min soaking time) and irradiated PP showed the best mechanical properties. Tensile strength, bending strength, tensile modulus, bending modulus and impact strength of the composites were found to improve 31, 41, 42, 46 and 84% higher over untreated composites. Water uptake, thermal degradation and dielectric properties of the resulting composites were also performed.     

Mechanical and viscoelastic properties of soybean oil thermoset reinforced with jute fabrics and carded lyocell fiber

Composites and hybrid composites were manufactured from renewable materials based on jute fibers, regenerated cellulose fibers (Lyocell), and thermosetting polymer from soybean oil. Three different types of jute fabrics with biaxial weave architecture but different surface weights, and carded Lyocell fiber were used as reinforcements. Hybrid composites were also manufactured by combining the jute reinforcements with the Lyocell. The Lyocell composite was found to have better mechanical properties than other composites. It has tensile strength and modulus of about 144 MPa and 18 GPa, respectively. The jute composites also have relatively good mechanical properties, as their tensile strengths and moduli were found to be between 65 and 84 MPa, and between 14 and 19 GPa, respectively. The Lyocell‐reinforced composite showed the highest flexural strength and modulus, of about 217 MPa and 13 GPa, respectively. In all cases, the hybrid composites in this study showed improved mechanical properties but lower storage modulus. The Lyocell fiber gave the highest impact strength of about 35 kJ/m², which could be a result of its morphology. Dynamic mechanical analysis showed that the Lyocell reinforced composite has the best viscoelastic properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Fabrication and comparative mechanical,electrical and water absorption characteristic properties of multifunctional epoxy resin of bisphenol-C and commercial epoxy-treated and -untreated jute fiber-reinforced composites

Epoxy resin of bisphenol-C-formaldehyde (EBCF) was synthesized and its structure was confirmed by FTIR and ¹HNMR techniques. Untreated jute and a 4 % sodium hydroxide-treated jute composites of EBCF, araldites (GY508 and GY6010) and their hybrid composites were fabricated by hand layup technique followed by compression-molding technique. Mechanical, electrical and water absorption behavior of the composites was studied by standard test methods. The composites showed good mechanical and electrical properties, excellent hydrolytic stability and almost identical water absorption tendency. To some extent, alkali-treated jute composites displayed improved mechanical properties and water absorption tendency. EBCF-based jute and hybrid composites showed comparable mechanical and electrical properties and water absorption behavior with araldite-based composites. Among jute–EBCF, jute–araldite and their hybrid composites, J–EBCF showed the highest impact strength (26 kg m^?2), Barcol hardness (34), volume resistivity (2.7 × 10^?11 Ω cm) and diffusivity (7.19 × 10^?13 m² s^?2). J–GY-1 showed the highest tensile strength (43.7 MPa), flexural modulus (4.26 GPa), % equilibrium water absorption (19.36 %) and equilibrium water absorption time (480 h). Good mechanical and electrical properties and excellent hydrolytic stability of both types of the composites suggested their usefulness for low load-bearing housing, and electrical and marine applications. Thus, EBCF has found its commercial importance as that of the commercial araldite resins.     

A Comparative Study on the Mechanical,Degradation and Interfacial Properties of Jute/LLDPE and Jute/Natural Rubber Composites

Jute fabric (hessian cloth) reinforced low-density polyethylene (LLDPE) composites (40 wt%) and solid natural rubber-(NR) based composites (40 wt%) were fabricated by compression molding. Tensile strength (TS), tensile modulus (TM) and percentage elongation at break (Eb) of jute/LLDPE composites were found to be 29, 680 MPa and 20%, and for jute/NR-based composites were also found to be 15, 122 MPa and 94%, respectively. Interfacial shear strength (IFSS) of the jute/LLDPE and jute/NR systems was investigated by using the single fiber fragmentation test (SFFT). Scanning electron microscopy (SEM) and aqueous degradation tests were also performed.     

Synthesis and physicochemical study of bisphenol‐C‐formaldehyde‐toluene diisocyanate polyurethane–jute and jute–rice husk/wheat husk composites

Bisphenol‐C‐formaldehyde‐toluene‐2,4‐di isocyanate polyurethane (PU) has been synthesized at room temperature and used for the fabrication of jute and jute–rice husk/wheat husk hybrid composites. PU–jute and PU–jute–RH/WH composites were prepared under pressure of 30.4 MPa at room temperature for 8 h, while PU–jute–RH/WH composites were prepared under same pressure at 110°C for 5 h. PU–jute composite has good tensile strength and flexural strength (50–53 MPa), while PU–jute–RH/WH hybrid composites have moderate tensile strength (9–11 MPa) and a fairly good flexural strength (15–31 MPa). Composites possess 1.1–2.2 kV electric strength and 0.94–1.26 × 10¹² ohm cm volume resistivity. Water absorption in PU–jute composite is different in water (9.75%), 10% HCl (12.14%), and 10% NaCl (6.05%). Equilibrium water uptake time in salt environment is observed 96 h, while in pure water and acidic environments it is 192 h. In boiling water equilibrium water content and equilibrium time are found to be 21.7% and 3 h, respectively. Water absorption increased 2.2 times in boiling water, whereas equilibrium time reduced 64 times. Thus, PU–jute composite has excellent hydrolytic stability against boiling water, 10% HCl, and 10% NaCl solutions. Fairly good mechanical and electrical properties and excellent hydrolytic stability of composites signify their usefulness for low cost housing units and in electrical and marine industries. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2363–2370, 2006     

Fabrication and Mechanical Characterization of Calcium Alginate Fiber-Reinforced Polyvinyl Alcohol Based Composites

Calcium alginate fibers were prepared from sodium alginate by extruding aqueous sodium alginate solution (4% by weight) into a calcium chloride (2% by weight) bath. Water uptake and mechanical properties of the calcium alginate fiber were investigated. Water uptake tests of calcium alginate showed that it absorbed 50% of water within a minute and indicated strong hydrophilic nature. Polyvinyl alcohol (PVA)-based calcium alginate fiber reinforced unidirectional composites (10% fiber by weight) were fabricated by compression molding. Tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS) of the PVA matrix and the composite were evaluated. TS, BS, TM, and BM of the PVA matrix were found 10, 18, 320 and 532 MPa, respectively. TS and BS of the PVA based composite were found to be 16 and 27 MPa, respectively, which were 60 and 50% higher than that of the PVA matrix. TM and BM of the composite were found to be 620 and 1056 MPa, respectively, which were improved by 94 and 98% over the matrix material. Degradation tests of the composites were performed for up to 2 months in soil medium and found that composites lost almost 50% of its original mechanical properties. The interfacial properties of the composite were also investigated by using the single fiber fragmentation test (SFFT).     

Preparation and Characterization of Bioblends from Gelatin and Linear Low Density Polyethylene (LLDPE) by Extrusion Method

Abstract

Bioblends are composites of at least one biodegradable polymer with a non-biodegradable polymer. Successful development of bioblends requires that the biodegradable polymers be compatible with other component biodegradable/synthetic (non-biodegradable) polymers. Bioblends from LLDPE and gelatin were prepared by extrusion and hydraulic heat press technique. The gelatin content in the bioblends was varied from 5 to 20 wt%. Various physico-mechanical properties such as tensile, bending, impact strength (IS), thermal ageing and soil degradation properties of the LLDPE/gelatin bioblends with different gelatin contents were evaluated. The effect of thermal ageing on mechanical properties was studied. The mechanical properties such as tensile modulus (TM), bending strength (BS), bending modulus (BM) were found to increase with increasing gelatin content up to 20 wt%, however tensile strength (TS) and elongation at break (%E _b) were decreased with increasing gelatin content. Impact strength value increased with increasing gelatin content up to 10 wt% and then decreased slightly with increasing gelatin content. The blend containing 20 wt% gelatin showed relatively better mechanical properties than other blends. The values of TS, TM,%E _b, BS, BM and IS for the bioblend with 20 wt% gelatin content are 5.9MPa, 206.3MPa, 242.6%, 12.1MPa, 8 MPa and 13.7 J/cm², respectively. Water uptake increases with increasing soaking time in water and weight loss due to soil burial also increases with increasing gelatin content in the blends but both are significantly lower than that of pure gelatin sheet. Weight loss values after thermal ageing increase with time, temperature and increasing gelatin content in the blend but are much lower than pure gelatin. Mechanical properties such as TS, TM are increased and %E _b is decreased after thermal ageing at 60°C for 30 min. Consequently, among all of the bioblends prepared in this work the blend having 20% gelatin content yields properties such that it can be used as a semi-biodegradable material.     

Thermomechanical and Interfacial Properties of Calcium Alginate Fiber-Reinforced Polypropylene Composites

Polypropylene (PP) matrix calcium alginate fiber reinforced unidirectional composites (10% fiber by weight) were fabricated by compression molding. Tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM), and impact strength (IS) were found to be 26 MPa, 950 MPa, 38 MPa, 1320 MPa, and 20 kJ/m², respectively. Degradation tests of composites were performed for 6 weeks in soil and it was found that composites retained almost 75% of its original strength. The interfacial properties of the composite were investigated by using single fiber fragmentation test (SFFT) and by scanning electron microscope (SEM).     

Effect of Coupling Agent Concentration,Fiber Content,and Size on Mechanical Properties of Wood/HDPE Composites

In this study, the influence of coupling agent concentration (0 and 3 wt%), wood fiber content (50, 60, 70, and 80 wt%), and size (40–60, 80–100, and 160–180 mesh) on the mechanical properties of wood/high-density-polyethylene (HDPE) composites (WPCs) was investigated. WPC samples were prepared with poplar wood-flour, HDPE, and polyethylene maleic anhydride copolymer (MAPE) as coupling agent. It was found that the tensile properties and the flexural properties of the composites were improved by the addition of 3 wt% MAPE, and the improved interfacial adhesion was well confirmed by SEM micrographs. It was also observed that the best mechanical properties of wood/HDPE composites can be reached with larger particle size in the range studied, while too-small particle size was adverse for the mechanical properties of wood/HDPE composites. Moreover, the tensile modulus, tensile strength, and flexural strength of WPCs decreased with the increase in fiber content from 50 to 80 wt%; the flexural modulus of WPCs increased with the increase in fiber content from 50 to 70 wt% and then decreased as the fiber content reached 80 wt%. The variances in property performance are helpful for the end-user to choose an appropriate coupling agent (MAPE) concentration, wood fiber content, and particle size based on performance needs and cost considerations.     

Effect of alkaline treatment on physical,mechanical, and thermal characteristics of jute filler reinforced epoxy composites

With burgeoning environmental concerns worldwide, using natural fibers/fillers to produce composites rather than conventional fibers is on the rise. The current work focuses on the physical and thermomechanical characteristics of alkaline-treated jute filler-based epoxy composites. The composites have been prepared with different weight fraction of jute fillers (0%, 2.5%, 5%, 7.5%, 10%, and 12.5%) using hand layup process. The X-ray diffraction and Fourier transform infrared spectroscopy analysis observed that the alkali treatment of jute fillers improved the crystallinity and molecular structure, enhancing the interfacial and molecular bond between fillers and matrix. The mechanical characterizations of developed composites analyzed that the inclusion of treated jute fillers strengthened the tensile and flexural properties. The 5% filler-based composites have demonstrated maximum tensile strength (54.06 MPa) and modulus (3.12 GPa) with maximum flexural strength (67.55 MPa) and modulus (3.90 GPa). The viscoelastic characteristics of composites revealed that the 7.5% filler-based composite has the highest storage modulus (3.75 GPa), loss modulus (0.496 GPa), and glass transition temperature (91°C) due to greater interfacial interactions of molecules. The weight loss and degradation of composites analyzed with thermogravimetric analysis, and observed better thermal stability with treated jute fillers. The morphological analysis at fracture surfaces analyzed the brittle catastrophic failure of composites. Therefore, the finding produced better specific strength and stiffness with greater thermal stability for electronics equipment, packaging, and transportation.     

Preparation and Physico-Chemical Study of Sandwich Glass-Jute-Bisphenol-C-Formaldehyde Resin Composites

Glass-Jute-bisphenol-C-formaldehyde (Glass-Jute-BCF) sandwich composites were prepared by hand lay-up technique at 150°C under 30.4 MPa pressure for 2 h. The resin, glass and jute fiber content in the sandwich composite were 33.3, 10.4 and 56.3 wt%, respectively. 10 prepregs containing 8 inner prepregs of jute mats sandwiched between 2 outer prepregs of glass mats. Glass-Jute-BCF sandwich composite has 23 MPa tensile strength, 119 MPa flexural strength, 1.72 kV/mm electric strength and 1.25 × 10¹² ohm cm volume resistivity. Tensile strength and volume resistivity both decreased, while flexural strength and electrical strength both improved upon hybridization. Sandwich composite showed high diffusivity in water, 10% NaCl and 10% HCl solutions as compared to Glass-BCF composite. Equilibrium water absorption time is found to be 72 h in all 3 environments. Comparatively low diffusivity is observed due to silane treated glass fibers. No effect of boiling water is observed on stability of composite. Saturation time in boiling water reduced 18 times without any damage to the composite. Glass-Jute-BCF sandwich composite may be useful for low load bearing applications in construction, electrical and electronic industries as well as in harsh acidic and saline environments.     

Effect of Sodium Bicarbonate on the Mechanical and Degradation Properties of Short Jute Fiber Reinforced Polypropylene Composite by Extrusion Technique

Short jute fibers and the pellets of polypropylene (PP) were compounded to make composites with the help of an extruder followed by compression molding. The mechanical properties of the composites increased with the increase of fiber content up to 20%, then decreased while the jute content varied from 5 to 30 wt%. Composites with varying percentages (5 to 20%) of sodium bi-carbonate at constant (20%) jute content were made by same process. The mechanical properties, soil degradation tests, and the water uptake capacity of the composites were investigated properly. Also, the density of the composite was reduced up to 21.54%.     

Study on Mechanical and Dielectric Properties of Jute Fiber Reinforced Low-Density Polyethylene (LDPE) Composites

Abstract

Jute fiber (Hessian cloth) reinforced low-density polyethylene (LDPE) composites were prepared by heat press molding techniques. The mechanical properties such as tensile strength (TS), bending strength (BS), and elongation at break of the composites were studied. The enhancement of TS (33%) and BS (50%) were obtained as a result of reinforcment jute fabrics in LDPE. In order to improve the mechanical properties and adhesion between jute and LDPE, hessian cloth were each treated with 2-hydroxyl ethyl methacrylate (HEMA). The HEMA-treated jute composite showed higher tensile and bending strength compared to untreated jute composite and LDPE. Dielectric properties like dielectric constant and loss tangent (tan δ) of jute, LDPE and composites were studied. Ferro to paraelectric phase transition occurred in both treated and untreated jute composites containing more than 20% jute. Water uptake behaviors of the composite were monitored and HEMA-treated composite showed lower water absorption behavior. The adhesion nature of jute and LDPE also characterized by scanning electronic microscopy (SEM), better adhesion was observed between HEMA-treated jute and LDPE over untreated ones.     

Biocomposites developed using water‐plasticized wheat gluten as matrix and jute fibers as reinforcement

Biocomposites developed from wheat gluten using water without any chemicals as plasticizer and jute fibers as reinforcement have much better flexural and tensile properties than similar polypropylene composites reinforced with jute fibers. Wheat gluten is an inexpensive and abundant co‐product derived from renewable resources and is biodegradable but non‐thermoplastic. Previous attempts at developing biocomposites from wheat gluten have used plasticizers such as glycerol or chemical modifications to make gluten thermoplastic. However, plasticizers have a considerably negative effect on the mechanical properties of the composites and chemical modifications make wheat gluten less biodegradable, expensive and/or environmentally unfriendly. In the research reported, we developed composites from wheat gluten using water as a plasticizer without any chemicals. Water plasticizes wheat gluten but evaporates during compression molding and therefore does not affect the mechanical properties of the composites. The effect of composite fabrication conditions on the flexural, tensile and acoustic properties was studied in comparison to polypropylene composites reinforced with jute fibers. Wheat gluten composites had flexural strength (20 MPa), tensile strength (69 MPa) and tensile modulus (7.7 GPa) values approximately twice those of polypropylene composites. Water is an effective plasticizer for wheat gluten and could be used to develop various types of inexpensive and biodegradable wheat gluten‐based thermoplastics. Copyright © 2011 Society of Chemical Industry     

Proton-conducting ceramics as electrode/electrolyte materials for SOFC's—part I: preparation,mechanical and thermal properties of sintered bodies

The aim of these investigations was to prepare and to examine compounds of a high temperature solid oxide fuel cell with a proton conducting electrolyte in view of the mechanical and thermal properties. The powders were made by the conventional solid reaction of carbonates and oxides. The stoichiometry of the electrolyte Ba,Ca niobate (BCN) was varied with x=0, x=0.12 and x=0.18. As potential cathode material SrCeO₃ and SrZrO₃ stabilised with 5% Yb was prepared, and as anode material cermet of BCN and Ni with 50:50 wt.% was synthesised. The mechanical properties like bending strength (room and high temperature), Young modulus (E), modulus of rigidity (G), Poison's ratio, micro hardness and fracture toughness were measured on sintered samples. The highest values for bending strength, E and G could be found for BCN12 (156 MPa, 160 GPa, 63 GPa) and the cerate (175 MPa, 145 GPa, 56 GPa), the lowest for the cermet BCN/Ni (72 MPa, 68 GPa, 29 GPa). The investigation of the thermal properties of the bulk material showed a thermal stability to a temperature of 1400 °C. The thermal expansion coefficient measured at 1000 °C was found to be in the range of 10–12×10⁻⁶/K. Further investigations with respect to the mechanical and thermal properties have to be made for the whole system of cathode–electrolyte–anode.