Natural Dyeing of Wood Fibers for Green Biocomposites

Abstract

In this study, the mechanical and thermal properties of green biocomposites adding natural dye were investigated by tensile test and Differential Scanning Calorimetry (DSC). Poly(lactic acid), one of biodegradable polymers recently been interested for replacing petroleum-based polymers, was compounded with wood fibers to produce biocomposite, and natural dyes were introduced to improve appearance of biocomposite. Pine wood fibers were dyed with three types of natural dyes; yellow color from heartwood of Jackfruit tree, red color from Sappan wood, and blue color from Indigo blue. Prior compounding, original and dyed wood fibers were treated with silane to improve compatibility between wood fiber and polymer matrix. It is found that %crystallinity of alkali-treated and natural dyed wood/PLA biocomposites were significantly higher than original wood/PLA biocomposites. The modulus and tensile strength of natural dyed wood poly (lactic acid) composites were in the same level of alkali-treated wood composites; however, elongation at break was improved by natural dye.