Enhancing Composite Performance: Hydrothermally Treated Wood Reinforcement in Recycled Polypropylene
The low thermal stability of cellulose presents unique technological challenges to the formulation of wood and plastic composites that are compatible and processable. For this, hydrothermal modification is a well-established technology for improving dimensional stability and durability of wood’s components, in addition to providing better interaction with the polymer. This study produced polymer composites in which hydrothermally treated wood waste fibers (WT) reinforce a recycled polypropylene (RPP) matrix. Wood waste fibers were selected by grain size and distribution, treated hydrothermally, and characterized by SEM, ATR-FTIR, and water sorption. Composites were produced varying the reaction time of treatment hydrothermal (from 30 to 180 minutes), granulometric size (from 425 to 1400 μm) and percentage of WT (from 10 to 20%), following a 2³ full-factorial experimental design, by extrusion with internal recirculation and the mechanical test specimens were modulated by injection. Tensile, flexion, IZOD impact and water sorption tests were statistically analyzed. Reaction time was the most statistically significant factor. Composites of wood waste fibers treated for 30 min and containing 20% of WT presented better mechanical properties than expected. However, the preservation of the lamellar fibers during the reaction time allowed for better adherence to the polymer, and the insertion of a greater quantity of fibers in the material provided greater rigidity in the composite. In general, the results obtained gives properties of stability and resistance to damage of composites containing hydrothermally treated wood fibers.
