Effect of fibre length and chemical modifications on the tensile properties of intimately mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites (original) (raw)
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Polymer, 1996
The effect of chemical treatment on the tensile properties of sisal fibre-reinforced LDPE (low density polyethylene) composites was investigated. Treatments using chemicals such as sodium hydroxide, isocyanate, permanganate and peroxide were carried out to improve the bonding at the fibre-polymer interface. The treatments enhanced the tensile properties of the composites considerably, but to varying degrees. The SEM (scanning electron microscopy) photomicrographs of fracture surfaces of the treated composites clearly indicated the extent of fibre-matrix interface adhesion. It has been demonstrated that the CTDIC (cardanol derivative of toluene diisocyanate) treatment reduced the hydrophilic nature of the sisal fibre and thereby enhanced the tensile properties of the sisal-LDPE composites. The SEM photomicrographs of the fracture surfaces have also shown that PE was highly bonded to the sisal fibre in CTDIC treated composites. The observed enhancement in tensile properties with the addition of small amounts of peroxides was attributed to the peroxide induced grafting of PE on to sisal fibre surfaces, as evident from the SEM photomicrographs of the fracture surfaces. It has been found that a low concentration of permanganate in the sisal-LDPE system during mixing considerably enhanced the mechanical properties. Among the various treatments, peroxide treatment of fibre imparted maximum interfacial interactions.
Fibre-matrix adhesion and properties evaluation of sisal polymer composite
Fibers and Polymers, 2015
Fibre matrix adhesions of sisal fibre with polymer were evaluated in terms of physico-chemical and mechanical properties. Effects of acetylation, acrylation, silanization, alkalization, and permanganate treatment on physical and chemical parameters as well as mechanical parameters such as tensile and impact behavior were investigated. Physical properties like density, moisture absorption, water absorption, void content and chemical properties like percentage of lignin, cellulose, and hemicelluloses were determined. From the findings, it was concluded that treatments such as acetylation, acrylation, and silanization can increase interfacial strength, wetting, and compatibility between fibre and matrix, leading to increase composite tensile strength. Acetylated sisal fibre and its polymer composites showed the highest tensile strength, less water absorption, and the acrylated sisal fibre composites showed the highest impact strength (46900 J/m 2).
Journal of Materials Science, 2000
Influence of sisal fibre content and different concentrations of dicumyl peroxide (DCP) on the thermal, mechanical and viscoelastic properties of short sisal fibre-linear low-density polyethylene (LLDPE) composites was investigated. Significant improvement of tensile strength was found after peroxide induced grafting between fibres and PE matrix. The stress relaxation measurements also suggest better stability upon prolonged loading of the samples prepared with 1% of DCP. It was shown, on the other hand, that higher DCP concentrations could have detrimental effects on the PE matrix, especially at low fibre contents. C 2004 Kluwer Academic Publishers
Composites Part A: Applied Science and Manufacturing, 2014
In this paper, we investigated the effect of fiber content, interfacial compatibilization, and manufacturing process on the mechanical properties (tensile, impact and creep) of sisal fiber (SF) reinforced high-density polyethylene (HDPE) composites. The increase of fiber content and interfacial compatibilization with maleic anhydride grafted HDPE (MAPE) were found to improve the mechanical properties of the composites. Compared with simultaneous blending, a pre-impregnation process with the compatibilizer, namely MAPE, improved the interfacial bonding between the fibers and the matrix, which in turn improved the mechanical properties of the composites. The General Power-Law equation was used to model the creep behavior of the composites. The identified material parameters based on the creep data were used to predict the creep-recovery behavior of the composites, and good agreement was achieved between the predicted and experimental creep-recovery responses.
Composites Science and Technology, 2007
Composites materials based on cellulose fibres (raw or chemically modified) as reinforcing elements and thermoplastic matrices were prepared and characterized, in terms of mechanical performances, thermal properties and water absorbance behaviour. Four different cellulose fibres with different average lengths were used, namely avicel, technical, alfa pulps and pine fibres. Two thermoplastic polymers, i.e. low density polyethylene and natural rubber, were employed as matrices. Cellulose fibres were incorporated into the matrices, as such or after chemical surface modification involving three silane coupling agents, namely c-methacryloxypropyltrimethoxy (MPS), c-mercaptoproyltrimethoxy (MRPS) and hexadecyltrimethoxy-silanes (HDS). As expected, the mechanical properties of the composites increased with increasing the average fibre length and the composite materials prepared using both matrices and cellulose fibres treated with MPS and MRPS displayed good mechanical performances. On the other hand with HDS bearing merely aliphatic chain only a modest enhancement on composite properties is observed which was imputed to the incapacity of HDS to bring about covalent bonding with matrix.
Journal of Applied Polymer Science, 2012
Three types of polyethylene (PE), low-density PE (LDPE), linear low-density PE (LLDPE), and highdensity PE (HDPE) were used as polymer matrices to prepare untreated as well as dicumyl peroxide (DCP) treated sisal fiber composites. The effect of polymer chain structure, addition of DCP, and sisal fiber loadings on the mechanical and dynamic mechanical properties of the composite was investigated in this study. It was found that the extent of improvement in tensile properties of the composite samples varied with respect to the polymer molecular characteristics. The elongation at break for all the composites decreased significantly. Young's modulus and the tensile strength of the treated LDPE and LLDPE composites increased significantly compared with the untreated composites, whereas Young's modulus of the treated HDPE samples decreased observably compared with the untreated samples. DCP treatment, however, did not change the tensile strength of HDPE and its composites. The storage modulus results for all the PE composites correlate well with the tensile testing results. In the case of the LDPE and LLDPE samples, the curves of the mechanical loss factor (tan d) show a clear relaxation around À18 C, which shifted to higher temperature in the treated composites, whereas for HDPE this transition was not seen.
2018
In this study, three types of polyethylene, low-density (LDPE), linear low-density (LLDPE), and high-density (HDPE) polyethylene, were used as polymer matrices to prepare sisal fibre reinforced polyethylene composites containing 10-30 wt% fibre. The untreated and the dicumyl peroxide (DCP) treated composites were prepared by melt mixing, followed by hot melt pressing. The influence of the DCP treatment, the polyethylene molecular characteristics, and the sisal fibre loadings on the morphology and on the thermal, mechanical, and dynamic mechanical properties of the composites was investigated. The gel contents of the composites varied significantly depending on the polyethylene molecular characteristics. The LLDPE composites had the highest gel content values followed by LDPE and then HDPE, for which the gel content did not change significantly. These results strongly suggested the presence of grafting of the polyethylene chains onto the sisal fibre surfaces combined with crosslinkin...
Hybrid polymeric composites reinforced with sisal fibres and silica microparticles
Composites Part B: Engineering, 2012
Polymeric composites reinforced with natural fibres have been developed in recent years, , showing with significant potential for various engineering applications due to their intrinsic sustainability, low cost, low weight and mechanical strength. The interfacial adhesion between natural fibres and polymeric matrices is critical to the composite performance. In order to improve the physical adhesion of polymeric composites, micro and nanoparticles have been added to synthetic fibres in the past. This work investigates the effect of silica microparticles, volume fraction of sisal and maleic anhydride on the mechanical properties of polymeric composites reinforced with unidirectional sisal natural fibres. A full factorial design (2 2 3 1 ) was carried out to identify the effect of these factors on the responses: bulk density, apparent density, apparent porosity, water absorption, mechanical strength and modulus of elasticity. A microstructure analyses was conducted to verify the interface condition. The volume fraction of fibres, silica addition, and the interaction between silica particles and maleic anhydride additions exhibited significant effects on the tensile strength and modulus of elasticity of the composites. The microsilica addition did not affect significantly the flexural strength; while the interaction between fraction of fibres, silica particles and maleic anhydride addition played a major role not only on the flexural strength, but also on the flexural modulus. The volume fraction of sisal fibres exhibited significant effects on the bulk density, apparent density, apparent porosity and water absorption of the composites.
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/mechanical-properties-of-polymer-matrix-composites-developed-from-fibre-glass-e-class-and-bisphenol-a-co-epichlorohydrine https://www.ijert.org/research/mechanical-properties-of-polymer-matrix-composites-developed-from-fibre-glass-e-class-and-bisphenol-a-co-epichlorohydrine-IJERTV2IS120465.pdf Polymer matrix composites have been developed in this work using fibre glass (E-class) with epoxy resin and various grades of amine as curing agents. The polymer matrix composites were produced from two fibres (fibre glass and 3-dimensional cotton fabrics) and epoxy resins. The epoxy resin was produced by dissolving a measured quantity of solid and liquid bisphenol-a-co-epichlorohydrine in Acetone. Three different amines (diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylene pentamine (TEPA)) were used as curing agents for the production work. The composites developed were subjected to tensile and hardness tests. The mechanical strength obtained is dependent on the grade and type of fibre used, the amine/epoxy ratio, epoxy/fibre weight ratio, thickness of the fibre and the use of additives as property modifiers. The results obtained showed that the tensile strength increases as the ratio of amine to epoxy ratio increases up to an optimal ratio of 0.17 when tetraethylenepentamine (TEPA) was used as the amine. The research work has also revealed that curing is best when tetraethylenepentamine was used as amine, followed by triethylenetetramine while diethylenetriamine produces week materials due to the number of reactive sites present for cross-linking processes. Tensile strength reduces as the ratio of epoxy to fibre weight increased beyond the optimal ratio of 0.16 due to presence of more unreactive epoxy in the mixture. The polymer matrix composite (PMC) developed has a tensile strength of 90.93N/mm 2 and Rockwell Hardness Number of 23.4 (HRF).
2013
Polymer matrix composites have been developed in this work using fibre glass (E-class) with epoxy resin and various grades of amine as curing agents. The polymer matrix composites were produced from two fibres (fibre glass and 3-dimensional cotton fabrics) and epoxy resins. The epoxy resin was produced by dissolving a measured quantity of solid and liquid bisphenol-a-co-epichlorohydrine in Acetone. Three different amines (diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylene pentamine (TEPA)) were used as curing agents for the production work. The composites developed were subjected to tensile and hardness tests. The mechanical strength obtained is dependent on the grade and type of fibre used, the amine/epoxy ratio, epoxy/fibre weight ratio, thickness of the fibre and the use of additives as property modifiers. The results obtained showed that the tensile strength increases as the ratio of amine to epoxy ratio increases up to an optimal ratio of 0.17 when tetraethylenepentamine (TEPA) was used as the amine. The research work has also revealed that curing is best when tetraethylenepentamine was used as amine, followed by triethylenetetramine while diethylenetriamine produces week materials due to the number of reactive sites present for cross-linking processes. Tensile strength reduces as the ratio of epoxy to fibre weight increased beyond the optimal ratio of 0.16 due to presence of more unreactive epoxy in the mixture. The polymer matrix composite (PMC) developed has a tensile strength of 90.93N/mm 2 and Rockwell Hardness Number of 23.4 (HRF).