The effect of argon and air plasma treatment of flax fiber on mechanical properties of reinforced polyester composite

Flax fibers were modified by argon and air atmospheric pressure plasma treatments to improve the mechanical properties of flax fiber-reinforced unsaturated polyester composites. Plasma treatments were carried out at plasma powers of 100, 200, and 300 W. Both plasma surface treatments were conducted to improve the tensile strength, tensile modulus, flexural strength, flexural modulus, interlaminar shear strength (ILSS), Mode I interlaminar fracture toughness (G _IC ), and Mode II interlaminar fracture toughness (G _IIC ). Moreover, the maximum improvement in the mechanical properties was obtained after air plasma treatment of flax fiber at a plasma power of 300 W. Tensile strength, flexural strength, ILSS, G _IC , and G _IIC values of flax fiber-reinforced polyester composites increased by nearly 34%, 31%, 39%, 35%, and 42%, respectively. However, for argon plasma-treated flax fiber-reinforced polyester composites, the mechanical properties of composite increased up to argon plasma power of 200 W.