The effect of long-term storage on the mechanical properties of composites based on polyamide 10.10 derived from renewable sources

This paper presents an investigation in which bio-based polyamide 10.10 was used as a polymer matrix. Composites were reinforced in three different ways including: 10 wt% and 30 wt% of walnut shell flour as well as 30 wt% of glass fibres. The composites were prepared by injection moulding. mechanical properties (tensile strength (σ_t), modulus of elasticity (E_t) as well as flexural modulus (E_f) and flexural stress at 3.5% strain (σ_f)) were obtained. The mechanical data of analysis showed that tensile strength and tensile stiffness significantly decreased after four years of storage. another state was noted for the bending module, where the decrease in value was at a level of 5% compared to results obtained immediately after injection. additionally, sem images were taken to assess the distribution of particles and the adhesion of fillers to the matrix.