Abstract The objective of this research was to develop a more sustainable composite and still keep its characteristics. Fibers treated with NaOH at 5% w/w for 2 hours were incorporated into natural rubber in different proportions (0 phr, 24 phr, 36 phr, 48 phr and 60 phr). The mechanical properties of the composites suffered changes, increasing the hardness, young’s modulus and decreasing its tensile strength. All the physical properties were not statistically different. The coloration became less dark in the WF60/CB0 treatment, and the electrical properties presented better resistivity with the increase in the concentration of fibers in the composite. This presents a possibility of using WF for the production of wood-rubber composites for the production of rubber artifacts which do not require high rolling resistance. Based on the results from this research, we recommended the WF24/CB36 mix to produce antistatic floors.

ABSTRACT The aim of this study was to evaluate the effect of the alkalization with different concentrations and time combination in the modification of lignin, hemicellulose and cellulose in pine fibers and determine the best combination aiming the incorporation in plant-based composites. The alkalization process was conducted with 5 concentrations (5, 10, 15, 20, and 30%) and 2 exposure times (2 and 24 hours). Chemical analysis was performed, and cellulose crystallinity, thermal stability, and surface modification were analyzed for the treated fibers. The results showed that there was a reduction in crystallinity with cellulose I – II transformation. Thereafter, the thermal stability and surface characteristics were increased with the increase of the NaOH concentration. Although all treatments altered the fiber properties, the condition that resulted in technical gain was the condition with 5% concentration and 2 hours of alkalization. Thus, we can conclude that this condition changes the macromolecular structure of the wood fibers, change the surface and the treat fiber could be used as filler to plant-base composite.