Effect of a Tertiary Oil Phase on the Mechanical Properties of Natural Fiber-Reinforced Polyester Composites

Previous study showed that adding linseed or pine oil to natural fiber-reinforced polyester composites significantly increased material biodegradability. However, it was not shown how the oils affected the composites' mechanical properties. This is the focus of this work. Hemp, bamboo and cotton are used as alternatives to the traditional fiberglass. Results show that the oil has more significant impact on the natural fiber-reinforced composites than ones reinforced with fiberglass. The oil mostly reduced surface microhardness and tensile properties, while increasing material ductility. Also, polymer matrix cracking behavior appears to depend on fiber type and oil presence inside the matrix.