OpuntiaFiber and Its Potential to Obtain Sustainable Materials in the Composites Field: A Review

Opuntia spp. is a plant widely distributed in the world that has traditionally been used in the food sector. Alternatively to the conventional uses of this plant, this work gives an overview of current knowledge about Opuntia fiber, focusing on several papers which have reinforced polymer matrices with this species. Opuntia cladodes are formed by a network of fibers with a hexagonal reticular hierarchical structure, which is believed to be responsible for their mechanical properties. Opuntia fiber has a cellulose content about 50% and a density (1.54 g/cm3) similar to conventional fibers such as abaca (1.5 g/cm3), jute (1.3 g/cm3) and sisal (1.5 g/cm3). Matrices such as polylactic acid (PLA) and polypropylene (PP) have been reinforced with Opuntia fibers and with ground cladodes, mainly by compression molding, increasing the tensile elastic modulus up to 135%. Opuntia fibers also offer good properties against energy absorption, being adequate for the design of lightweight materials with these characteristics. Further studies should be undertaken in order to establish the appropriate parameters to optimize fiber extraction, improve fiber-matrix compatibility and determine a general trend despite the plant own variability.