**4. Discussions**

From the results shown in this work the great potential of using piassava powder as a reinforcement in the COPU matrix for HPCF application was evident. Along with the results of a previous work [39], almost all standard requirements were attained. By comparing the results obtained for impact, abrasive wear and flexural strength with the results from FTIR analysis, there was space to improve the flexural strength of the material by further addition of piassava powder without greater loss of impact resistance and yet maintain the wear resistance at acceptable levels.

Finally, the use of the polyurethane material with approximately 60% volume fraction derived from castor oil (mass proportion use converted to the volume fractions) with a 30 vol% of piassava powder obtained as an industrial waste represented a biocomposite made almost 80% in volume from a renewable source. This alone represented a much greener solution compared to composites made with matrices or reinforcements from the non-renewable sources commonly applied in high-performance floors. Furthermore, the fact that the COPU resin used in this study was biodegradable, as well as the piassava powder, meant an environmentally friendly end-of-cycle alternative for natural materials.

To be used as HPCFs, according to the standard [10], the biocomposites are required to withstand a 10-year-long period. This can be a problem owing to the biodegradable characteristics of this biocomposite. However, the castor oil-derived polyol is reported to be antimicrobial, and the biocomposite itself can be designed to present a good resistance to biodegradability until its end of cycle [19]. Further studies should determine the life cycle times of these materials.
