Physical and mechanical characterization of Guazuma crinita Mart. composites based on virgin polypropylene

Abstract

Wood plastic composite materials based on Guazuma crinita wood particles (White Bolaina) from forestry thinning of 4, 5 and 6 years old and virgin polypropylene (PP) were prepared, using polypropylene maleic anhydride (MAPP) as a coupling agent. Specimens were made by extrusion, thermal compression and laser cutting. White bolaine particles were sieved with ASTM mesh sizes: -40/+60, -60/+80 and -80/+100. Proportions of polypropylene/Bolaina mixture were: 70/30, 80/20 and 90/10. All formulations included 2 % MAPP as a coupling agent. Physical properties as moisture content, density, absorption and swelling were assessed, as well as the mechanical properties of static bending, tension and impact resistance. Additionally, for discussing the results an anatomical characterization of the White Bolaina wood fiber (length, diameter, wall thickness, lumen diameter and slenderness coefficient) and a chemical analysis of its components (extractives, holocellulose, lignin and ash) was carried out. Results allow to appreciate a direct relationship between the variable mixing ratio and the mainly physical properties, as well as between the variable particle size with respect to tension. Wood age did not represent a significant source of variability.