Mubarak A. Khan

Study on the Mechanical Properties of Jute/Glass Fiber-reinforced Unsaturated Polyester Hybrid Composites: Effect of Surface Modification by Ultraviolet Radiation

Jute fiber (Hessian cloth) and E-glass fiber (mat)-reinforced, unsaturated polyester (USP) resin along with additives and initiator, composites are prepared by the hand layup technique at room temperature (25°C). Jute fiber content in the composites is optimized with the extent of mechanical properties, and composites with 25% jute show higher mechanical properties. The mechanical properties are found to increase with the incorporation of dissimilar portions of glass fiber into the jute fiber-reinforced composite. Among all the resulting hybrid composites, the composite with a jute to glass ratio of 1: 3 demonstrates improved mechanical properties, such as tensile strength (TS) 125%, tensile modulus (TM) 49%, bending strength (BS) 162%, and bending modulus (BM) 235% over untreated jute composite. To further improve the properties, the surface of jute and glass fiber is irradiated under UV radiation of different intensities. UV pretreated jute and glass fibers (1: 3) at optimum intensities show the highest mechanical properties, such as TS 70%, TM 33%, BS 40%, and BM 43% compared to untreated jute-and glass-based hybrid composites. UV-modified jute/glass-reinforced hybrid composites also show the best of Charpy impact strength (40 kJ/m2). The interfacial adhesion between jute/glass and USP is monitored by a scanning electronic microscope (SEM).

Comparative Studies of Mechanical and Interfacial Properties Between Jute and E-glass Fiber-reinforced Polypropylene Composites

Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, and impact strength of the composites were found to be 48 MPa, 2.5 GPa, 56 MPa, 4.5 GPa, and 18 kJ/m2, respectively. Then E-glass fiber (woven)-reinforced polypropylene-based composites (50 wt% fiber) were fabricated and the mechanical properties were compared with those of the jute-based composites. It was revealed that E-glass fiber-based composites had almost double the mechanical properties as compared to jute composites. The interfacial shear strength of the jute and E-glass fiber-based systems was investigated and found to be 2.13 and 4.66 MPa, respectively, measured using the single-fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were studied by scanning electron microscope and the results revealed poor fiber matrix adhesion for jute-based composites when compared to that of the E-glass fiber composites.

Mechanical and Electrical Properties of Jute Fabrics Reinforced Polyethylene/Polypropylene Composites: Role of Gamma Radiation

Jute fabrics reinforced polyethylene (PE), polypropylene (PP) and mixture of PP+PE matrices based composites (50 wt% fiber) were prepared by compression molding. It was found that the mixture of 80% PP + 20% PE hybrid matrices based jute fabrics reinforced composites performed the best results. Gamma radiation (250–1000 krad) was applied on PP, PE and jute fabrics then composites were fabricated. The mechanical properties of the irradiated composites (500 krad) were found to increase significantly compared to that of the non irradiated composites. Electrical properties like dielectric constant, loss tangent and conductivity with temperature variation of the composites were studied.

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

ABSTRACT 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.

Degradable jute plastic composites

A urethane prepolymer with an aliphatic chain, has been used to prepare a number of formulations, in the presence of plasticizers and monomers of different characteristics. Hessian cloth (jute product) is coated with these formulations and cured under u.v. radiation. Tensile properties (strength and elongation) of the jute plastic composite, thus formed with these formulations were found to increase. The treated jute products (composites) were buried in soil, semi-mud, mud and water in order to study the degradable character of the composite. It was found degradable in mud while the composite was not decomposable in water and soil. The composite was also treated under the simulated weathering conditions by alternating sunshine, and condensation and it was found that the composite was substantially decomposed under this condition.

Jute composite with MMA by gamma and UV radiations in the presence of additives

Jute yarns treated with MMA + MeOH solutions were irradiated either with Co-60 gamma source or with UV radiation. In gamma radiation, polymer loading of MMA (methyl methacrylate) onto jute increased quite substantially, but the strength of the composite decreases sharply after 15% polymer loading. The gamma-treated jute samples were very brittle. On the other hand, jute yarns irradiated in situ under UV radiation was found to be grafted with MMA. The tensile strength of the UV-cured jute yarn composite increases with an increase of grafting level, in contrast to the behavior observed with the gamma-irradiated jute composite samples. The tensile properties of the composites can be further enhanced by the incorporation of certain additives and coadditives into MMA + MeOH solutions. This opens diverse applications for jute materials.

In situ jute yarn composite with HEMA via UV radiation

Jute yarns soaked for 30 min in 2-hydroxyethylmethacrylate (HEMA) + MeOH solutions at different proportions [1–20% HEMA in MeOH (v/v)] were irradiated in situ with a UV lamp for different periods. The treated jute yarns that were washed in acetone after the irradiation to remove the unused excess monomer HEMA gained about 10% polymer loading with enhanced tensile strength (80%) and elongation (95%). The tenacity was not further increased by incorporation of a minute amount (1%) of novel additives into the HEMA + MeOH solutions, but elongation was enhanced up to 140% when the additive urethane acrylate (1%) was mixed with the solution.

Radiation-induced jute-plastic composite : Preparation and IR studies

Abstract Jute–plastic composite (JPC) has been prepared with tossa jute yarns and methylmethacrylate (MMA) mixed with methanol at different proportions using Co-60 gamma source irradiation. Incorporation of a minute amount (1%) of an additive like NVP, TPGDA, TMPTA, or urea substantially increased the grafting of MMA onto jute yarns. Different characteristic properties such as grafting, tensile properties, water absorption ability, and moisture absorption at different relative humidities have been determined. Both tensile strength (TS) and elongation (E b) of the composite decreased with increased grafting; however, at lower grafting, both TS and E b slightly increased. IR study reveals that MMA has been grafted onto jute cellulose at the sites of OH groups of the jute cellulose backbone.

Influence of Mercerization Along with Ultraviolet (UV) and Gamma Radiation on Physical and Mechanical Properties of Jute Yarn by Grafting with 3‐(Trimethoxysilyl) Propylmethacrylate (Silane) and Acrylamide Under UV Radiation

Abstract Jute yarns were pretreated by alkali (5% NaOH) and were grafted with two types of monomer such as 3‐(trimethoxysilyl)‐propylmethacrylate (silane) and acrylamide (AA) under ultraviolet (UV) radiation. The monomer concentrations were 30% in Methanol (MeOH) and irradiation times were 30 min and 60 min for silane and AA, respectively. The alkali‐treated silane‐grafted jute yarn produced enhanced tensile strength (TS) (265%), elongation at break (Eb) (350%) with 27% polymer loading (PL) and alkali‐treated AA‐grafted jute yarn produced enhanced TS (210%), Eb (270%) with 23% PL than that of virgin fiber. Again, the surface of jute yarns were pretreated by alkali along with UV and gamma radiation with different intensities and grafted with silane and acrylamide to further improve the tensile properties of the jute yarn. The jute yarns were pretreated with alkali and UV radiation and grafted with silane showed the best properties such as TS (360%), EB (380%) and 31% PL. Simulated weathering test and water uptake of untreated and treated jute yarns were studied. The alkali + UV‐pretreated silanized jute yarn showed lesser water uptake as well as less weight loss and mechanical properties as compared with treated samples.

Improvement of physico-mechanical properties of jute yarn by photografting with 3-(trimethoxysilyl) propylmethacrylate

Jute yarns were treated with an alkoxy silane monomer 3-(trimethoxysilyl) propylmethacrylate under UV radiation. The monomer concentration and radiation intensity were optimized with respect to the extent of grafting and mechanical properties of the grafted (silanized) jute yarn. The enhanced tensile strength by 159%, elongation-at-break (237%) and polymer grafting (26.2%) were observed when the yarn was treated at 30 wt% silane in methanol under UV radiation for 30 min. The surfaces of both treated and untreated jute yarns were characterized by X-ray photoelectron spectroscopy (XPS), Fourier-Transform Infrared Spectroscopy (FTIR) and Environmental Scanning Electron Microscopy (ESEM) and it was concluded that the silane reacted or deposited on jute surface as a result of UV radiation. Water uptake and degradation properties of untreated and silanized jute yarn were studied in various conditions such as simulated weathering and in soil containing 25% water. The silanized jute yarn showed lesser water uptake as well as less weight loss and mechanical properties as compared to virgin samples.