Effect of APPT Treatment on Mechanical Properties and Durability of Green Composites with Woven Flax

Through this study, two different natural fibres green composites were characterised from the point of view of mechanical properties and durability. These green polymers allow manufacturing with a respectful life cycle due to their biodegradable or recyclable character. Composite materials were prepared in a hot plates press with two biopolymeric matrices, green low density polyethylene (GPE) and polybutylene succinate (PBS). As reinforcement, Atmospheric Pressure Plasma Torch (APPT) treated and untreated unidirectional woven flax were used. Mechanical properties were evaluated by tensile tests and the adhesion between matrices and reinforcement by peeling tests. The durability of each composite was analysed by water absorption measurements, Fourier Transform Infrared Spectroscopy (FTIR) analysis and tensile tests, during several aging times, up to 60 days, under high temperature and humidity conditions. The influence of the Atmospheric Pressure Plasma Torch treatment (APPT) was evaluated in all studies. It was found that GPE composites present better durability against aging conditions than PBS materials, due to the tendency of polyester to hydrolyse compared to the good resistance to humidity of polyolefins. The adhesion between matrices and reinforcement improves with APPT treatment. This improvement is more evident by avoiding the absorption of water than in the mechanical properties results, where only a slightly improvement is shown.