Development and characterisation of hybrid napier/glass fibre reinforced epoxy composites

Abstract

Owing to serious environmental concerns in recent years, researchers have been driven to investigate the use of sustainable materials as a substitute for common polymer composites manufactured with synthetic fibres, such as glass, carbon, and aramid. This has generated increased interests in the development of natural fibre-reinforced composites. However, natural fibre composites have some limitations such as poor resistance to moisture absorption and possess lower impact strength. To further enhance the properties of natural fibre composites, reinforcements such as glass, carbon, and aramid fibres are hybridized into natural-fibre composites. The mechanical properties of hybrid Napier/glass fibre reinforced epoxy composites and, their durability under elevated temperatures and moisture exposure were characterised and investigated. The 5% alkali-treated fibre had achieved the maximum ultimate tensile stress of single fibre test. The hybrid composites with 5% alkali-treated Napier fibres exhibited the greatest tensile and flexural strengths. Observing the impacted surfaces, it can be noticed that the hybrid composites with untreated Napier fibres present less damage area. The moisture absorption of the hybrid Napier/glass fibres reinforced epoxy composites increased with the water-immersion period of the samples. As the temperature approached Tg, at >60 °C, the fibre would deboned from the matrix and consequently reduced the tensile and flexural strength of the material. This study is expected to provide evidence to support the development and application of this material.