Kenaf Bast Fiber Bundle–Reinforced Unsaturated Polyester Composites. I: Processing Techniques for High Kenaf Fiber Loading

Abstract

The fabrication of kenaf bast fiber bundle/unsaturated polyester composites with high (60% to 67, wt/wt) fiber contents was explored in this study. Mechanically ground kenaf bast fiber bundles were preformed into mats with a polyvinyl acetate emulsion adhesive. The preformed mats are easy to handle during subsequent processing with the unsaturated polyester resin and laminate compression molding. Fiber loadings as high as 65 percent (wt/wt) were achieved. The generated composites possessed high elastic moduli, and their tensile strengths were close to specification requirements for glass fiber–reinforced sheet molding compounds. These composites also exhibited higher specific tensile moduli and strengths than glass fiber–reinforced sheet molding compounds' specific modulus and strength lower bounds and those calculated from specification requirements for glass fiber–reinforced sheet molding compounds. If reduced void contents and enhanced interfacial binding can be achieved through improved processing, then natural fiber composites similar to those developed in this work have the potential to possess mechanical properties competing against those of currently used automotive sheet molding compounds.