Effect of plasma treatment of wood fiber on the wettability, dynamic mechanical and thermal properties of polypropylene composite panels

Abstract

This work evaluates the effect of plasma treatment on the wettability, dynamic mechanical and thermal properties of compression-molded composite panels produced from wood fiber (WF) and polypropylene (PP). Initially, WF was treated with different plasma durations (60, 120, and 180 s radiation). Afterward, the contact angle, moisture uptake, storage modulus, loss modulus, damping loss, and weight loss of the specimens prepared from untreated and plasma-treated were evaluated. Results revealed that the plasma treatment facilitates the interactions between WF and PP, and increases the adhesion properties. Compared with the lowest contact angle of 74.8° for the untreated specimens, the highest contact angle was found in the treated specimens around 79.06°, 81.29°, and 82.7°, using 60 and 15 using 180 s plasma radiations. Furthermore, the water absorption of the specimens reduced as a result of plasma treatment. The plasma-treated specimens demonstrated better molecular restriction and larger dynamic modulus than the unmodified ones. The tan δ peak signifying the glass transition temperature of composites shifted to a higher temperature, in the presence of plasma treatment. It was noted that the thermal stability of the composite panels produced from plasma-treated wood was remarkably improved.