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.     

Studies of the Physico-Mechanical,Interfacial, and Degradation Properties of Jute Fabrics/Melamine Composites

Jute fabrics/melamine composites (20% fiber) were prepared by compression molding. Mechanical properties of the composites were evaluated. Mechanical properties of starch-treated jute/melamine composites, including tensile strength (31%), bending strength (29%), tensile modulus (23%), bending modulus (25%), impact strength (113%), and hardness (4%), inproved significantly over the untreated composite. Fracture surfaces of untreated and treated composites were studied by scanning electron microscopy (SEM) and supported poorer fiber matrix adhesion for the untreated composite than that of the treated composite. Water uptake and soil degradation tests of untreated and treated composites were also performed.     

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.     

Comparative Studies on the Mechanical,Degradation and Interfacial Properties between Jute and E-Glass Fiber-Reinforced PET Composites

Jute fiber mat (hessian cloth) reinforced PET-based composites (50% fiber by weight) and E-glass fiber matreinforced PET based composites (50% fiber by weight) were fabricated by compression molding and the mechanical properties tensile strength (TS), tensile modulus (TM), elongation at break (%), bending strength (BS), bending modulus (BM), impact strength (IS) and hardness (Shore-A) of the composites were evaluated and compared. The interfacial properties of the both composites were also compared. Water uptake test and soil degradation test were also investigated.     

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.     

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).     

Interfacial adhesion in jute‐polyolefin composites

The interfacial adhesion between four different forms of jute fibers (sliver, bleached, mercerized and untreated) and polyolefinic matrices (LDPE and PP) was studied, as a critical factor affecting the mechanical behavior of these composites. The fiber‐matrix adhesion was estimated by means of the critical fiber length (l_c) and the stress transfer ability parameter (τ); such parameters were obtained by Single Fiber Composite (SFC) tests. Tests were carried out to evaluate the mean tensile strength of the fibers, the mean critical fiber lengths and the stress transfer ability parameter for every fiber‐matrix combination, according to Weibull's statistical method. Thermal‐mechanical characterization of the fibers was also carried out to evaluate the resistance to processing conditions. A limited degradation of strength was observed, which, however, does not preclude the use of jute fibers as reinforcing means in polyolefin based composites. It was found that the adhesion was better in PP‐jute composites than in LDPE‐jute composites. In both cases the results showed that the sliver jute and the untreated jute had better adhesion to both matrices than had the bleached and the mercerized fibers. With both matrices the interface adhesion was in the order: mercerized < bleached < untreated = sliver.     

Effect of γ‐aminopropyl trimethoxy silane on the performance of jute–polycarbonate composites

The composites of jute fabrics (hessian cloth) and polycarbonate were prepared by compression molding. The jute surface was modified with γ‐aminopropyl trimethoxy silane (Z‐6011) to improve interfacial adhesion between jute and polycarbonate. The treated and untreated jute surfaces as well as composites were investigated by X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Environmental scanning electron microscopy, Dynamic mechanical analysis, and mechanical testing. XPS and FTIR assure that the silane plays important role to form interfacial bonding with the jute fibers and polycarbonate. The surface topography of silanized and virgin fibers, and the interfacial adhesion properties of the composite were investigated by ESEM. DMA analysis shows the improved storage and loss moduli of silanized jute composite as compared to the untreated one. The modified jute composite also produces enhanced mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4142–4154, 2006     

汽车内饰用PP/黄麻纤维复合材料力学性能

采用转矩流变仪混合造粒,通过注射成型方法制备了聚丙烯(PP)/黄麻纤维复合材料,研究了对纤维表面进行处理的NaOH浓度、纤维含量和相容剂的含量对PP/黄麻纤维复合材料力学性能的影响,采用扫描电镜对纤维表面及复合材料的断面形貌进行分析。结果表明:黄麻纤维经过碱处理后PP/黄麻纤维复合材料的力学性能优于纤维未处理的复合材料的力学性能,随着NaOH浓度的提高,PP/黄麻纤维复合材料的拉伸强度和冲击强度增加,在NaOH浓度为16%时,其拉伸强度和冲击强度最佳;其弯曲强度随着NaOH浓度的提高先增加而后下降,在8%浓度时,弯曲强度最大。随着纤维含量的提高,PP/黄麻纤维复合材料的拉伸强度和弯曲强度先增加后下降,在纤维含量达到20%时,PP/黄麻纤维合材料的拉伸强度和弯曲强度达到最大。随着纤维含量的提高,PP/黄麻纤维复合材料的冲击强度降低。相容剂的加入使得PP/黄麻纤维复合材料的拉伸强度和弯曲强度明显增加。     

Effect of γ-Radiation on the Mechanical Performance of Hybrid Rice Straw/Seaweed-Polypropylene Composites

Hybrid composites of rice straw (Rs)/seaweed (Sw) and polypropylene (PP) were prepared at a fixed filler ratio of 30:70 and variable ratio of the two reinforcements, viz. 30:0, 25:5, 20:10, 10:20, 0:30 by weight. Mechanical properties of the composites such as tensile strength (TS), bending strength (BS), impact strength (IS) and elongation at break (Eb%) were investigated and the composite formulation of 20:10:70 (Rs:Sw:PP) was found to be optimum that showed TS = 2.8 MPa, BS = 68 N/mm², IS = 2.5 kJ/mm² and Eb = 50%. For better compatibility, Rs and Sw were subjected to surface treatment using various intensities of γ-radiation to prepare improved hybrid composites. γ-irradiated filler hybrid composites significantly enhanced mechanical properties and the composite in which fillers were irradiated at 100 krad achieved maximum enhancement with TS = 35 MPa, BS = 75 N/mm², IS = 2.7 kJ/mm² and Eb = 68%. Water absorption capacity of the different composites was also studied and irradiated filler composites showed less water uptake.     

Effects of methyl methacrylate grafting and polyamide coating on the interfacial behavior and mechanical properties of jute‐fiber‐reinforced polypropylene composites

In recent years, environmentally friendly materials have become popular because of the growing environmental demands in human society. Natural fibers are now widely used as reinforcements in polymer matrix composites for their various advantages such as low cost, light weight, abundant resources, and biodegradability. However, the applications of these kinds of composites are limited because of their unsatisfactory mechanical properties, which are caused by the poor interfacial compatibility between the fibers and the thermoplastic matrix. In this paper, three methods, including (i) alkali treatment, (ii) alkali and methyl methacrylate (MMA) treatment, and (iii) alkali and polyamide (PA) treatment (APT), were used to treat jute fibers and improve the interfacial adhesion of jute‐fiber‐reinforced polypropylene (PP) composites (JPCs). The mechanical properties of the JPCs were tested, and their impact fracture surfaces were observed. Infrared spectral analysis showed that MMA was grafted and that PA was coated onto the surface of jute fibers. Mechanical tests indicated that the three kinds of pretreated composites presented better mechanical properties than untreated composites. Among them, the APT composite had the best comprehensive properties. Compared with untreated composites, the tensile strength, flexural strength, and flexural modulus of APT composite were increased by 24.8, 31.3, and 28.4%, respectively. Analysis by scanning electron microscopy showed that better interfacial compatibility between jute fibers and PP occured in this kind of composite. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers     

Mechanical performance of hybrid rice straw/sea weed polypropylene composites

Rice straw (Rs)/polypropylene (PP) composites were prepared in the different ratio of 5 : 95, 10 : 90, 15 : 85, 20 : 80, 25 : 75, and 30 : 70 (Rs wt % : PP wt %) by an injection molding process. This work investigated the tensile strength (TS), bending strength (BS), and impact strength (IS) of the composites. From the results, it is observed that Rs20 : PP80 mixture composite showed better performance with mechanical properties (TS = 26.2 MPa, BS = 58 N/mm², and IS = 1.7 KJ/mm²) among the composites prepared. Two hybrid composites were also fabricated using 20% Rs, 10% seaweed with 70% PP and 20% Rs, 30% seaweed with 70% PP. In between the two hybrid composites, superior mechanical behavior showed by the hybrid composite in ratio of Rs20 : Sw10 : PP70 with enhanced results such as TS = 28 MPa, BS = 68 N/mm², and IS = 2.5 KJ/mm². Water uptake, simulating weathering, and soil degradation test of different composites were also performed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Tensile,flexural and impact properties of jute fibre-based thermosetting composites

Abstract

The present study reports static and impact mechanical properties of jute fibre-based thermosetting composites using woven and flat braided jute fabrics. Tensile, three-point flexural and low-to-medium energy drop-weight impact tests were conducted and mechanical properties were evaluated to study their dependence upon surface modifications of the fibre materials due to bleaching and coating treatments. Full-bleaching (longer and rigorous) treatments improved interfacial bonding and tensile strength properties of the woven jute composites compared to unbleached and half-bleached counterparts. Bleaching treatments did not seem to improve the flexural strength of composites. Unbleached (natural) jute composites have relatively better flexural strength due to reduced microstructural waviness or fibre crimping to facilitate flexural failure. With coated jute yarns, the tensile properties of the resultant flat braided composites slightly degraded, whereas the flexural properties showed clear improvements. The changes in the mechanical properties were broadly related to the accompanying modifications and to the state of microstructural imperfections, namely fibre/matrix interfacial adhesion, severity of resin matrix shrinkage during the curing process, fibre/matrix debonding and distribution of disbonds within the matrix region, and also to the relative fibre filament density along the loading axis, in the cured composite structure. There was a clear indication that natural woven jute composites could be more effective in applications requiring better impact damage resistance, energy absorption capability and improved progressive crushing behaviour.     

Study on Effect of Incorporation of Gelatin Fiber in Jute Fabrics-Reinforced Linear Low Density Polyethylene Composite

Jute fabrics (50%)-reinforced linear low density polyethylene (LLDPE) composite was prepared by compression molding and mechanical properties were studied. Gelatin fiber (2%–10%) was incorporated into the jute fabrics-based composites and their mechanical properties were investigated and compared with the control composite. It was found that with the increased of gelatin fiber content in the jute fabrics-based composites, the mechanical properties were found to be decreased, but water uptake and degradation properties were increased significantly. The composite containing 10% gelatin fiber lost 30.2% of its weight, 56.4% TS, 41.8% BS, 26% TM and 25.5% BM after 24 weeks in soil medium.     

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 alkali treatment on properties of unidirectional isora fibre reinforced epoxy composites

Abstract

Unidirectional isora fibre reinforced epoxy composites were prepared by compression moulding. Isora is a natural bast fibre separated from Helicteres isora plant by retting process. The effect of alkali treatment on the properties of the fibre was studied by scanning electron microscopy (SEM), IR, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Mechanical properties such as tensile strength, Young's modulus, flexural strength, flexural modulus and impact strength of the composites containing untreated and alkali treated fibres have been studied as a function of fibre loading. The optimum fibre loading for tensile properties of the untreated fibre composite was found to be 49% by volume and for flexural properties the loading was optimised at ～45%. Impact strength of the composite increased with increase in fibre loading and remained constant at a fibre loading of 54·5%. Alkali treated fibre composite showed improved thermal and mechanical properties compared to untreated fibre composite. From dynamic mechanical analysis (DMA) studies it was observed that the alkali treated fibre composites have higher E' and low tan δ maximum values compared to untreated fibre composites. From swelling studies in methyl ethyl ketone it was observed that the mole percentage of uptake of the solvent by the treated fibre composites is less than that by the untreated fibre composites. From these results it can be concluded that in composites containing alkalised fibres there is enhanced interfacial adhesion between the fibre and the matrix leading to better properties, compared to untreated fibre composites.     

Role of Amino Acids on In Situ Photografting of Jute Yarn with Acrylamide Using Ultraviolet Radiation

Abstract

To improve the mechanical performance of jute yarn, grafting with acrylamide (AM) monomer has been performed on in situ UV radiation and optimized; the monomer concentration (30%) and irradiation time (60 min) attained 195% tensile strength with 22% polymer loading (PL). The effect of amino acids (1%) as additives in AM with photografted jute yarn at optimized system has been studied. The PL and tensile properties, such as tensile strength (TS) and elongation at break (Eb), of treated samples were enhanced by incorporation of amino acids, and the highest TS value (270%) and Eb value (300%) with 27% PL value were achieved by the sample treated with L‐arginine (Arg). Weak acid [3% acetic acid (Ace)] and strong acid [1% sulfuric acid (Sul)] were also incorporated in the optimized system of AM grafting to investigate their effect on the mechanical properties of photografted jute yarn. Water absorption and weathering resistance of treated untreated samples (TS₀) were also studied.     

NOVEL LOW-COST JUTE–POLYESTER COMPOSITE. II. SEM OBSERVATION OF THE FRACTURED SURFACES

The scanning electron micrographs (SEM) were taken at different magnifications with respect of the fractured surfaces of the polymer composites prepared from unsaturated polyester resin and jute sliver with 60% fiber loading by weight. The composite specimens were prepared using both untreated (control) and chemically modified (bleached) jute fibers by solution impregnation and hot curing methods and are designated as JPH-60(C) and JPH-60(B), respectively. The method of preparation of the composite specimens have been discussed. The specimens were subjected to tensile and flexural tests and the fractured surfaces were observed under SEM as stated. The fiber surface morphology was also studied from the SEM photographs in the case of the control and bleached jute filaments. The SEM photographs of the fractured surfaces of the composites showed varied extents of fiber pull-outs under both tensile and flexural failure modes. The nature of interfacial adhesion has been discussed on the basis of the SEM study. A good correlation between the SEM study and the mechanical strength properties of the composites could be established. Exceptionally high flexural strength of the composites JPH-60(B) compared to JPH-60(C) could be explained from the SEM study.     

Effects of alkali and silane treatment on the mechanical properties of jute‐fiber‐reinforced recycled polypropylene composites

Jute‐fibers‐reinforced thermoplastic composites are widely used in the automobile, packaging, and electronic industries because of their various advantages such as low cost, ease of recycling, and biodegradability. However, the applications of these kinds of composites are limited because of their unsatisfactory mechanical properties, which are caused by the poor interfacial compatibility between jute fibers and the thermoplastic matrix. In this work, four methods, including (i) alkali treatment, (ii) alkali and silane treatment, (iii) alkali and (maleic anhydride)‐polypropylene (MAPP) treatment, and (iv) alkali, silane, and MAPP treatment (ASMT) were used to treat jute fibers and improve the interfacial adhesion of jute‐fiber‐reinforced recycled polypropylene composites (JRPCS). The mechanical properties and impact fracture surfaces of the composites were observed, and their fracture mechanism was analyzed. The results showed that ASMT composites possessed the optimum comprehensive mechanical properties. When the weight fraction of jute fibers was 15%, the tensile strength and impact toughness were increased by 46 and 36%, respectively, compared to those of untreated composites. The strongest interfacial adhesion between jute fibers and recycled polypropylene was obtained for ASMT composites. The fracture styles of this kind of composite included fiber breakage, fiber pull‐out, and interfacial debonding. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers.