Sustainable Wood Plastic Composite Materials From Chile Fibers and Thermoplastics

Wood plastics are material composites made of plant biomass and polymer blends that exhibit useful properties that surpass those of the individual components, and are predicted to play important roles in sustainable markets. Some WPCs use recycled materials, resist decay, and insect attack. Weathering capabilities of WPCs excel over individual components such as wood. They are dimensionally stable which results in little to no splintering, cracking, or warping. WPCs can be produced in engineered profiles by any thermosets or thermoplastic processing techniques. Although wood plastic composites are biomaterials with many benefits and advantages over other materials currently used in the market, they do present some challenges. The combination of a hygroscopic (biomass) and hydrophobic (plastic) materials can cause issues in the compatibilization process of wood-fiber plastic composites.  The melting index of plastic can also cause molding difficulties as well as the blending of additives which are known to increase proper fiber dispersion, increase outdoor performance, and increase ultimate tensile strength and yield strength. This study focuses on a new wood plastic composite based on pre-dried New Mexico’s red chile pepper stems and leaves with high density polyethylene. The effects of proportions and particle sizes on the strength of the resulted blend were studied. A series of experiments were designed showing that wood fiber length, geometry, and content strongly affect the microcellular structure of the new sustainable material.  It was found that larger particle sizes of wood fiber showed an increase in ultimate tensile strength and yield strength.