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     

Thermal,Mechanical and Morphological Characterization of Jute/Gelatin Composites

Jute fabrics/gelatin biocomposites were fabricated using compression molding. The fiber content in the composite varied from 20–60 wt%. Composites were subjected to mechanical, thermal, water uptake and scanning electron microscopic (SEM) analysis. Composite contained 50 wt% jute showed the best mechanical properties. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength of the 50% jute content composites were found to be 85 MPa, 1.25 GPa, 140 MPa and 9 GPa and 9.5 kJ/m², respectively. Water uptake properties at room temperature were evaluated and found that the composites had lower water uptake compared to virgin matrix.     

Sustainable conducting polymer composites: study of mechanical and tribological properties of natural fiber reinforced PVA composites with carbon nanofillers

ABSTRACT

Ball milled jute fiber (JF) was added to Polyvinyl Alcohol (PVA)/20 wt.% multi-layer graphene (MLG) composites in various proportions (0, 5, 10, 15 and 20 wt.%) to prepare sustainable and biodegradable conducting polymer composites. Also, PVA/17.5wt.%MLG/2.5wt.%MWCNT/20wt.% JF composite was prepared for comparison purpose. A dynamic mechanical analysis of the composites was conducted to analyze their viscoelastic nature. The electrical conductivity of the composites was measured to study their suitability for various applications. Jute reinforcement increased the electrical conductivity of PVA/MLG nanocomposites. The PVA/20wt.%JF/17.5wt.%MLG/2.5wt.%MWCNT hybrid composite had the highest electrical conductivity of 3.64 × 10^?4 S/cm among all the composites prepared. Multilayered structures of the hybrid composite films were made by hot-pressing, and their effectiveness in electromagnetic interference shielding was tested. The shielding effectiveness of the composites decreased with jute addition. The wear resistance of PVA/MLG/JF composites increased with an increase in the jute content up to an optimum value of 10 wt.%, and then it started deteriorating.     

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.     

Mechanical and thermal properties of epoxy-POSS reinforced-(biphenyl diol formaldehyde/epoxy hybrid resin) composites

To enhance the properties of epoxy composites, the biphenyl diol formaldehyde resin (BPFR) and glycidyloxypropyl polyhedral oligomeric silsesquioxane (G-POSS) were synthesized and used for modification of fiber-glass reinforced composites of epoxy resin (ER). The BPFR was employed to cure epoxy resin with different G-POSS contents and the laminates of fiber-glass reinforced hybrid composites prepared from BPFR, ER and G-POSS. The dynamic mechanical properties, thermal properties, mechanical and electrical properties of the hybrid composites were characterized by dynamic mechanical analyzer, thermogravimetric analyzer and electroproperty detector. The results showed that the T _g of the composites is increased with the addition of G-POSS. When the content of G-POSS is 5 wt%, the tensile and impact strength of the hybrid composites are 249.87 MPa and 63.83 kJ/m², respectively, which are all 30 % higher than those of non-added composites. At G-POSS content of 7 wt%, T _g of the material is 9.6 °C higher than pure BPFR/ER composite, and the initial decomposition temperature, T _id, is enhanced by about 29 °C. Dielectric constant, ε, and dielectric loss, tanδ, of the hybrid composites are between 0.53–0.7 and between 0.004–0.012, respectively.     

Improvement of Mechanical Properties of Jute Fibers-Polyethylene/Polypropylene Composites: Effect of Green Dye and UV Radiation

Jute-reinforced polyethylene (PE), polypropylene (PP) and mixture of PP/PE composites were prepared. It was found that 90% PP and 10% PE matrices based jute reinforced composites performed the better results. UV radiation at different intensities was applied both on matrices and jute. Mechanical properties of the irradiated jute- and matrices-based composites were found to increase significantly. Optimized jute fabrics were also treated with different concentrations of green dye (0.1–1%, w/w) with 2% K₂O₈S₂ in methanol solution for 2–8 min. A composite made of 0.5% green dye jute (5 min soaking time) and irradiated matrix showed the best mechanical properties.     

The Fabrication and Characterization of Cellulose/Mesoporous Silica Composites Packaging Films with Adjustable Permeability by NMMO Technology

Cellulose-based composites containing various amounts of SBA-15 mesoporous silica were prepared by NMMO-technology, and their morphologies, mechanical properties, permeability for oxygen and water vapor were studied. The investigation suggested that both the modified and unmodified mesoporous silica materials can improve the elongation at break of the cellulose films. However, the incorporation of the mesoporous silica materials can reduce the tensile strength of the films, and the modified one has less effect on that than the unmodified one. The composites films with rational mechanical properties have adjustable oxygen permeability (7.90 × 10^?15–94.6 × 10^?15 cm³ · cm/cm² · s · Pa) and water vapor permeability (7.12 × 10^?13–4.10 × 10^?13 g · cm/cm² · s · Pa).     

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     

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.     

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     

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.     

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.     

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.     

Mechanical,Electrical and Water Absorption Study of Jute/Glass/Jute-bamboo/Glass-bamboo-bisphenol-C-formaldehyde-acrylate a Value Added Composites

Bisphenol-C-formaldehyde-acrylate (BCFA) resin was synthesized by reacting 0.1 mol bisphenol-C-formaldehyde resin, 0.4 mol acrylic acid in 25 ml 1,4-dioxane and 1.5 g phenothiazine catalyst at 80°C for 6 h. Jute, glass, jute-bamboo, and glass-bamboo composites were prepared by compression molding technique at 150°C for 2 h under 30.4 MPa pressure. Jute-BCFA, Glass-BCFA, Jute-bamboo-BCFA, Glass-Bamboo-BCFA possess 50, 114, 49, and 65 MPa tensile strength; 58, 185, 69, and 70 MPa flexural strength; 1.2, 3.3, 1.3, and 1.9 kV/mm electric strength and 6.2 × 10¹², 2.5 × 10¹³, 6.6 × 10¹², and 1.5 × 10¹³ ohm cm volume resistivity. The data are interpreted in terms of nature of fibers and resin and fiber loading and orientation. Water absorption behavior of composites is tested in pure water, 10% NaCl and 10% Hcl solutions at room temperature as well as in boiling water. Observed diffusivity order for each of composite is H₂O < NaCl < HCl. Sandwich composites shown high water absorption in all media due to high bamboo fiber loading and fiber agglomeration. The presence of HCl and NaCl affected the water structure and hence diffusivity. Jute-bamboo-BCFA and Glass-Bamboo-BCFA delaminated in boiling water within half an hour. Mechanical and electrical properties and water absorption behavior are affected by the nature of fibers and matrix, fiber loading and fiber arrangement. Fairly good mechanical and electrical properties of Jute-BCFA and Glass-BCFA and their low water absorption behavior signify their usefulness as low load bearing applications. Composites signify their use for low load bearing applications in construction, electrical and marine industries.     

Synthesis and characterization of novel poly(aniline-co-m-aminoacetophenone) copolymer nanocomposites using dodecylbenzene sulfonic acid as a soft template

A series of dodecylbenzene sulphonic acid (DBSA) doped poly(aniline-co-m-aminoacetophenone) copolymer composites of different compositions were synthesized in micellar solution of DBSA to obtain nanosphere morphology with enhanced processability. The plausible mechanism for the formation of poly(aniline-co-m-aminoacetophenone)-DBSA copolymer composite has been presented. These DBSA doped copolymer composites were characterized by UV–Visible, FTIR spectroscopy and XRD analysis techniques. UV–Vis absorption spectrum of the composites showed 325 and 637 nm which corresponds to the π–π* and n–π* transition. In FTIR spectroscopy a broad band around 2,924 cm^?1 corresponds to C–H vibration of DBSA indicating good agreement with the characteristic bands of DBSA. The sharp band at 1,292 cm^?1 is assigned to C–N stretching mode of vibration of N–Ph–N units. The X-ray diffraction of composites reveals that these composites are amorphous in nature. The number of diffraction peaks decreased with increase in the m-aminoacetophenone content. It indicates that these composites are amorphous in nature. Morphological studies (SEM) reveal that these composites have a spherical morphology with the average size of 100–200 nm. These composites exhibit electrical conductivity value of 0.744 × 10^?3 S/cm and enhanced solubility than polyaniline. Moreover, at the presented work, the DBSA doped copolymer composites were obtained in high yields by keeping an oxidant to co-monomer ratio of 1:1.     

Enzyme‐mediated surface modification of jute and its influence on the properties of jute/epoxy composites

Surface modification of jute fibers is necessary to improve the adhesion and interfacial compatibility between fibers and resin matrix before using fibers in polymer composites. In this study, dodecyl gallate (DG) was enzymatically grafted onto the jute fiber by laccase to endow the fiber with hydrophobicity. A hand lay‐up technique was then adopted to prepare jute/epoxy composites. Contact angle and wetting time measurements showed that the surface hydrophobicity of the jute fabric was increased after the enzymatic graft modification. The water absorption and thickness swelling of the DG‐grafted jute fabric/epoxy composite were lower than those of the other composites. The tensile and dynamic mechanical properties of the jute/epoxy composites were enhanced by the surface modification. Scanning electron microscopy images revealed stronger fiber–matrix adhesion in composites with modified fibers. Therefore, the enzymatic graft modification increased the fiber–matrix interface area. The fiber–matrix adhesion was enhanced, and the mechanical properties of the composites were improved. POLYM. COMPOS., 38:1327–1334, 2017. © 2015 Society of Plastics Engineers     

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.     

Preparation,Mechanical and Electrical Properties of Glass and Jute–Epoxy/Epoxy Polyurethane Composites

Glass and jute (treated and untreated) composites of epoxy resin of 1,1′-bis(3-methyl-4-hydroxy phenyl)cyclohexane(EMC) cured using 20% triethylamine as a hardener (G-EMCT-20 and J-EMCT-20) and EMC- polyurethane of toluene diisocyanate (J-EMCPU and TJ-EMCPU) have been prepared by a hand layup technique under 27.58 MPa pressure and at 150°C for 4 h. G-EMCT-20, J-EMCT-20, J-EMCPU and TJ-EMCPU showed 275, 96.5, 37.3 and 31.5 MPa tensile strength; 351, 84, 10 and 24 MPa flexural strength; 5837, 2758, 1277 and 1619 MPa elastic modulus; 24.6, 7.1, 1.9 and 1.6 kV/mm electric strength; and 1.4 × 10¹³, 1.1 × 10¹¹, 7.7 × 10¹⁰ and 3.6 × 10¹⁰ ohm cm volume resistivity, respectively. Fairly good to excellent mechanical and electrical properties of the composites indicated their industrial applications in building and construction, electrical and electronic industries.     

Effect of lactic acid chain length on thermomechanical properties of star‐LA‐xylitol resins and jute reinforced biocomposites

Star‐shaped bio‐based resins were synthesized by direct condensation of lactic acid (LA) with xylitol followed by end‐functionalizing of branches by methacrylic anhydride with three different LA chain lengths (3, 5 and 7). The thermomechanical and structural properties of the resins were characterized by ¹³C NMR, Fourier transform IR spectroscopy, rheometry, DSC, dynamic mechanical analysis (DMA), TGA and flexural and tensile tests. An evaluation of the effect of chain length on the synthesized resins showed that the resin with five LAs exhibited the most favorable thermomechanical properties. Also, the resin's glass transition temperature (103 °C) was substantially higher than that of the thermoplast PLA (ca 55 °C). The resin had low viscosity at its processing temperature (80 °C). The compatibility of the resin with natural fibers was investigated for biocomposite manufacturing. Finally, composites were produced from the n5‐resin (80 wt% fiber content) using jute fiber. The thermomechanical and morphological properties of the biocomposites were compared with jute‐PLA composites and a hybrid composite made of the impregnated jute fibers with n5 resin and PLA. SEM and DMA showed that the n5‐jute composites had better mechanical properties than the other composites produced. Inexpensive monomers, good thermomechanical properties and good processability of the n5 resin make the resin comparable with commercial unsaturated polyester resins. © 2017 Society of Chemical Industry