Okra fibres, which are cropped in a number of countries across several continents, may represent a suitable example of by-product from an agricultural productive system involving mainly food-related applications. This offers a low cost availability of ligno — cellulosic fibres, which may be used for different possible purposes. In this regard, a number of issues were investigated, in particular their possible introduction as a filler, possibly with some reinforcement effect, both in conventional thermosetting and bio­degradable thermoplastic matrices. This involved an evaluation of the effectiveness of different chemical treatments in modifying the resistance and morphology of the fibres, which, as microscopical investigation demonstrated, is rather variable with regard to diameters, lumen dimensions and overall shape. A possible alternative to application of okra fibres in the dimensions of technical fibres, therefore on the microscale, is their use as sources of CNC with the idea of providing a filler, usually applicable in small amounts, for biodegradable matrices, such as poly(vinyl alcohol) (PVA).

In general terms, the results obtained suggest that most suitable fields of applica­tions for okra fibres in the material sector may refer to their use in the packaging industry, therefore mainly linked to the application of biodegradable matrices in short life products.