Strength Of Biocomposites Research Articles

Viscoelasticity and impact behaviour of green epoxy bio-composites made of date palm leaflets

Natural fibres can replace traditional synthetic fibre composites in applications for which sustainability is a critical aspect. Elghas date palm leaflets in their natural state and with handwoven fabric reinforcements—the latter from customary and regional carpet productions—are included into new bio-based composites that are produced and characterized in this work. The two classes of bio-composites have the same weight fraction in terms of reinforcement. The date palm leaflets reinforcements are dispersed in a green resin matrix. Bio-composites reinforced with leaflets tree have twice the static bending strength than those with leaflets fabric reinforcements. The viscoelastic behaviour of those bio-composites shows an opposite trend, with the laminates reinforced with leaflets fabric being the least sensitive. For an impact energy of 3 J, the strength of bio-composites with leaflets fabric is double than the analogous value shown by bio-composites with leaflets tree. The impact strength however increases by 4.7 times for lower impact energies of 1 J. The results shown here further demonstrate the possibility of developing bio-composites from agro-industrial products, waste, and local textile traditions for secondary structural applications.

The effect of polyurethane binder and glass fiber reinforcement on physical and mechanical properties of mahogany (Swietenia mahagoni) leaves waste biocomposite

In this work, the effect of polyurethane binder and glass fiber as reinforcement on the physical and mechanical properties of mahogany (Swietenia mahagoni) leaves waste as biocomposite was investigated. Mahogany leaves waste has been successfully synthesized into a strong and lightweight biocomposite material by using a polyurethane binder and glass fiber as reinforcement. The mass content of polyurethane was varied between 0.25?1.50 g to obtain the optimum conditions. The contents of glass fiber added were between 0.1?0.5 g for biocomposite reinforcement. The addition of polyurethane and glass fiber mass fraction on biocomposite from mahogany leaves waste affected the physical and mechanical properties. The optimum ratio of mahogany leaves waste and polyurethane binder to produce biocomposite showed a compressive strength of 41.59 MPa, a density of 1.060 g/cm3, water absorption of 6.98%, and a thickness development of 7.27%. The addition of glass fiber material was proven to increase the compressive strength of biocomposites to 57.68 MPa. The addition of glass fiber to biocomposites also succeeded in improving physical properties. The testing of glass fiber reinforced biocomposites resulted in a density of 1.140 g/cm3, water absorption of 5.42%, and thickness development of 8.18%.

The Effect of Kenaf Loading on Water Absorption and Impact Properties of Polylactic Acid/ Natural Rubber/ Kenaf Core Powder Biocomposite

Abstract Polylactic acid (PLA)/natural rubber (NR)/ kenaf core powder (KF) biocomposite was prepared via melt blending in internal mixer followed by hot pressed. The loading of kenaf was varied at five different loadings (0 phr, 5 phr, 10 phr, 15 phr, 20 phr). Kenaf core powder is gradually added to study the effect of kenaf loading on the biocomposite based on water absorption and impact properties. Water absorption percentages of biocomposite increased with increasing kenaf loading attributed from the hydrophilicity of kenaf itself. Field emission scanning electron microscope (FESEM) was utilized to study the impact fractured surface and filler-matrix adhesion. Addition of kenaf core powder was found to deteriorate the impact strength of biocomposite due to poor interfacial adhesion as proven by FESEM micrograph.

Fabrication and characterization of dental mirror product using polylactic acid biocomposites

ABSTRACTPolylactic acid biocomposites were prepared by mixing castor oil and talc by melt blending using twin-screw extruder. The amount of talc and castor oil was fixed at 20 and 1 wt%, respectively. The biocomposites were analyzed using Fourier transform infrared spectroscopy, impact strength, bioactivity, cytotoxicity, and soil burial tests. Using biocomposites, mouth mirror product was fabricated for oral dental application using injection molding machine. The impact strength of biocomposites increases by 56% than neat polylactic acid. Bioactivity and cytotoxicity tests of the biocomposites prove that they have no toxicity and the product can be used for oral dental application.

THERMAL AND MECHANICAL PROPERTIES OF BIOCOMPOSITES BASED ON GREEN PE-HD AND HEMP FIBERS

Biocomposites of hemp fiber reinforced bio-based high density polyethylene (green PE-HD) were prepared using a maleic anhydride grafted styrene–ethylene/butylene–styrene (SEBS-g-MA) as a compatibilizer. Several compositions of biocomposites were prepared on a tween screw extruder using the full factorial design varying two factors with two levels. The mechanical and thermal properties of test specimens, prepared by injection molding, were investigated by tensile and bending tests, DMA, and ultra-fast differential dynamic calorimetry (Flash DSC). High stiffness and strength of biocomposites in comparison to neat green PE-HD indicate very good compatibility of the constituents. Stiffness of the samples without SEBS-g-MA is slightly higher than that of the samples with SEBS-g-MA. The thermal stability of biocomposites is for all samples drastically higher as compared to neat green PE-HD. The melting (Tm) and crystallization (Tc) temperatures of the biocomposites are shifted to higher temperatures. Incorporation of SEBS-g-MA together with hemp fiber into the matrix enhances strength, stiffness, impact strength and rises thermal stability. The novel biocomposites are suitable for applications such as technical parts, which require higher stiffness and thermal stability as compared to neat green PE-HD.

THERMAL AND MECHANICAL PROPERTIES OF BIOCOMPOSITES BASED ON GREEN PE-HD AND HEMP FIBERS

Biocomposites of hemp fiber reinforced bio-based high density polyethylene (green PE-HD) were prepared using a maleic anhydride grafted styrene–ethylene/butylene–styrene (SEBS-g-MA) as a compatibilizer. Several compositions of biocomposites were prepared on a tween screw extruder using the full factorial design varying two factors with two levels. The mechanical and thermal properties of test specimens, prepared by injection molding, were investigated by tensile and bending tests, DMA, and ultra-fast differential dynamic calorimetry (Flash DSC). High stiffness and strength of biocomposites in comparison to neat green PE-HD indicate very good compatibility of the constituents. Stiffness of the samples without SEBS-g-MA is slightly higher than that of the samples with SEBS-g-MA. The thermal stability of biocomposites is for all samples drastically higher as compared to neat green PE-HD. The melting (Tm) and crystallization (Tc) temperatures of the biocomposites are shifted to higher temperatures. Incorporation of SEBS-g-MA together with hemp fiber into the matrix enhances strength, stiffness, impact strength and rises thermal stability. The novel biocomposites are suitable for applications such as technical parts, which require higher stiffness and thermal stability as compared to neat green PE-HD.

The Effects of Antioxidants Content on Mechanical Properties and Water Absorption Behaviour of Biocomposites Prepared by Single Screw Extrusion Process

The performance of hybrid fillers between rice husk and sawdust filled recycled high density polyethylene (rHDPE) with the presence of antioxidants (IRGANOX 1010 and IRGAFOS 169, with the ratio of 1 : 1) was investigated. The biocomposites with 30 wt% of matrix and around 70 wt% of hybrid fillers (rice husk and sawdust) and different antioxidants’ contents (0 to 0.7 wt%) were prepared with single screw extruder. Increasing the amount of antioxidants in biocomposites reduced the modulus of elasticity and modulus of rupture on flexural testing. The addition of antioxidants increased the tensile and impact strength of biocomposites. From the study, samples with 0.5 wt% of antioxidants produce the most reasonable strength and elasticity of biocomposites. Furthermore, the effect of antioxidants content on water uptake was minimal. This might be caused by the enhanced interfacial bonding between the polymer matrix and hybrid fillers, as shown from the morphology by using scanning electron microscopy (SEM).

Sustainable Cellular Biocomposites from Natural Fibers and Unsaturated Polyester Resin for Housing Panel Applications

Increased environmental awareness and interest in long-term sustainability of material resources has motivated considerable advancements in composite materials made from natural fibers and resins, or biocomposites. In spite of these developments the lower stiffness and strength of biocomposites has limited their applications to non-load-bearing components. This paper presents an overview of a study aimed at showing that the shortcomings of biocomposites can be overcome through hybrid material designs and efficient structural configurations to make them suitable for load bearing structural components. Hybrid blends of natural and synthetic fibers can significantly improve the characteristics of biocomposites with minimal cost and environmental impact, and hierarchical cellular designs can maximize material efficiency in structural components. Periodic and hierarchical cellular plate designs made from natural fibers and unsaturated polyester resin were evaluated experimentally and analytically. Stiffness, strength, and dimensional stability of all-biocomposite and hybrid natural–synthetic material systems were evaluated through material tests while structural performance of cellular plate designs was assessed through flexural tests on laboratory-scale samples. The experimental results were correlated with analytical models for short-fiber composites and cellular structures. The results showed that biocomposites have adequate short-term performance and that they can efficiently compete with housing panels made from conventional structural materials.