Time-dependent degradation behaviour of phosphate glass fibre reinforced composites with different fibre architecture

In this study, biodegradable Polylactic acid (PLA) composites reinforced with phosphate glass fibres (PGF) using different fibre architecture (UUU, CCC, UCU and CUC) were prepared via compression moulding process. The maximum initial flexural strength and modulus were observed for unidirectional (UD) fibre reinforced composites (UUU), whereas CCC composites with thoroughly chopped fibre reinforcement exhibited the lowest values. The sandwich structure of UCU composite with 50% UD reinforcement in the skin and 50% chopped fibre in core exhibited similar flexural properties in comparison to UUU composites, meeting the flexural property requirements of cortical bone. Furthermore, the degradation behaviour and mechanical performance of composites with different fibre architecture were analysed during the degradation process for 28 days. The UUU composites showed the most rapid degradation of the flexural performance. Meanwhile, a lower reduction of flexural properties was observed for UCU composites due to less susceptibility to wicking in discontinuous fibres. As such, the UCU composite could provide near flexural performance with better retention of properties during the degradation.