Nonwoven Alkali Treated Kenaf Fiber Mat - Unsaturated Polyester Composite Under Hygrothemal Aging

The hygrothermal effect on unsaturated polyester composites containing 30% by volume of untreated and alkali treated nonwoven kenaf fiber along with neat resin have been studied. The kinetics of water uptake was investigated by immersing neat resin and composites at room temperature, 60 degrees C and 90 degrees C. Alkali treatment significantly reduced the water uptake and the diffusivity of composite at all aging temperatures; thereby the alkali treated kenaf fiber composites showed better durability of flexural properties. Elevated temperatures aging promoted the severe degradation of samples, and subsequent drying could not restore the flexural properties.