SISAL

About: SISAL is a research topic. Over the lifetime, 1878 publications have been published within this topic receiving 55528 citations.

Effect of silver coating on electrical properties of sisal fibre-epoxy composites

Abstract: In this paper, the effect of silver coating and size of fibre on electrical properties of sisal fibre-reinforced epoxy composites has been reported. For this purpose, epoxy composites reinforced with silver-coated sisal (of 5 and 10 mm length) prepared by hand moulding and samples were characterized for their electrical properties, such as dielectric constant (e′), dielectric dissipation factor (tan δ) and AC conductivity (σ ac), at different temperatures and frequencies. It was observed that dielectric constant increases with increase in temperature and decreases with increase in frequency from 500 Hz to 5 kHz. The peak height at the transition temperature decreases with increasing frequency. Interestingly, sample having silver-coated fibre of 5 mm length exhibited higher value of dielectric constant as compared to the sample having 10 mm of fibre length, which is attributed to the increased surface area of coated fibre. This behaviour of the material can be explained in terms of interfacial polarization. At a constant volume of fibres and at a length of 5 mm, the number of interfaces per unit volume element is high and this results in high interfacial polarization. The number of interfaces decreases as the fibre length increases and therefore the value of e′ decreases at 10 mm fibre length. To study the changes in structure of samples, Fourier transform infrared spectrometry and scanning electron microscopy of the samples were carried out.

Mechanical properties of sisal-epoxy composites as functions of fiber-to-epoxy ratio

Abstract: Low density, low cost, environmental compatibility, wide availability, and high mechanical performance of raw materials are some considerable advantages of natural fiber composites. Sisal, very common type of natural fiber, is abundantly available in Ethiopia. This research aims to investigate mechanical properties of sisal reinforced composites such as tensile, flexural and impact strength. Fabrication of samples used the hand lay-up process with 15, 25, 30, 35, and 40 wt% sisal fiber to epoxy ratio. Tests for the properties indicated were made using the instron material testing system. Test results demonstrated, among the samples, that 30 wt% of sisal fiber-reinforced composites have the maximum tensile and flexural strength of 85.5 MPa and 85.79 MPa respectively. The impact strength has been found to be maximum for 40 wt% sisal fiber which is 24.5 kJ/m2. As the result show, and compared with other researcher findings, the mechanical properties are acceptable as substitutes for applications demanding low-cost engineering applications such as automotive internal parts including interior door panel, back seat and body panels.

Bio-Based Polyurethane Composites and Hybrid Composites Containing a New Type of Bio-Polyol and Addition of Natural and Synthetic Fibers

Abstract: This article describes how new bio-based polyol during the liquefaction process can be obtained. Selected polyol was tested in the production of polyurethane resins. Moreover, this research describes the process of manufacturing polyurethane materials and the impact of two different types of fibers-synthetic and natural (glass and sisal fibers)-on the properties of composites. The best properties were achieved at a reaction temperature of 150 °C and a time of 6 h. The hydroxyl number of bio-based polyol was 475 mg KOH/g. Composites were obtained by hot pressing for 15 min at 100 °C and under a pressure of 10 MPa. Conducted researches show the improvement of flexural strength, impact strength, hardness, an increase of storage modulus of obtained materials, and an increase of glass transition temperature of hard segments with an increasing amount of fibers. SEM analysis determined better adhesion of sisal fiber to the matrix and presence of cracks, holes, and voids inside the structure of composites.

Analysis of Mechanical, Thermal, and Dynamic Mechanical Behaviors of Different Polymer-Coated Sisal Fibers

Abstract: In this study, the surface of sisal fiber has been modified by coating with different polymers The influence of surface modification on tensile strength, thermal behavior, storage modulus, and dissipation factors has been determined by using fiber tensile tester, differential scanning calorimetry, and dynamic mechanical analysis Tensile strengths of uncoated sisal fiber and sisal coated with low-density polyethylene, polystyrene (PS), polyvinyl alcohol, polypropylene, polyester, and araldite epoxy are 5930, 280, 381, 1848, 1983, 2736, and 1041 MPa, respectively In the coated fibers, the maximum tensile strength was found for PS-coated sisal fiber and minimum for epoxy-coated sisal fiber, which is explained based on their fractured microstructures The storage modulus value of PS-coated sisal fiber determined at 100°C for all frequency was maximum