Okra fibres as potential reinforcement in biocomposites

The need to find environmentally friendly alternatives to traditional synthetic fibres such as glass fibres to be used as reinforcement in polymer matrix composites has attracted a growing interest in natural plant fibres in the last decade. In this regard, this chapter provides a comprehensive overview on a less common, but promising, natural fibre known botanically as Abelmoschus esculentus. It focuses on the origin, history and use of this plant with a particular emphasis on the fibres extracted from the stem of this plant, also known as okra fibres. A comprehensive mechanical, morphological and thermal characterization of the fibres is addressed in this work aiming at investigating their possible use as reinforcement in polymer matrix composites. The addition of okra fibres in thermoplastic and thermosetting matrices is reviewed, while the last part of the chapter is devoted to the development of cellulose-based nanocomposites, which is unanimously perceived as one of the most promising research fields related to plant-based products. The extraction of cellulose nanocrystals from okra fibres and their incorporation in thermoplastic composites is described. The problems that appear as limiting factors for possible application of okra fibres as reinforcement for semi-structural components are highlighted and discussed.