A Comparative Study Between Bio-composites Obtained with Opuntia ficus indica Cladodes and Flax Fibers

This work is aimed to study the suitability of the wooden backbone of Opuntia ficus indica cladodes as reinforcement for the production of bio-composites. The wooden backbone can be extracted from O. ficus indica cladodes, which constitute a very relevant agricultural scrap, and is characterized by a thick walled cellular structure. In view of its potential in poly-lactic acid (PLA) matrix bio-composite production, two different possible applications were examined. In the first alternative, the wooden backbone was used in replacement of flax fibers for the production of fully consolidated bio-composites. Results obtained have shown that, though being characterized by lower properties compared to those of flax fiber composites, the opuntia actually works as an efficient reinforcement for PLA/wood flour matrix, increasing the flexural strength and elongation at break. In the second alternative, the cellular structure was used for the production of a sandwich bio-composite with a PLA/wood flour skin. In this case, the very high interlaminar adhesion strength between the skin and the core was considered as an indication of the potentiality of this material for the production of high strength sandwich structures. As a confirmation of this, no interlaminar debonding was observed during short beam tests.