Damage in extrusion additive manufactured biomedical polymer: Effects of testing direction and environment during cyclic loading

Although biodegradable polymers were widely researched, this is the first study considering effect of combined testing environments and cyclic loading on most important aspect related to additive manufacturing : interfacial bond between deposited layers. Its results give confidence in applicability material extrusion technology for biomedical fields , by demonstrating that interface behaves a manner similar bulk-polymer material. To do this, especially designed tensile specimens used analyse degradation 3D-printed subjected constant-amplitude incremental loads when tested air at room temperature (control) submerged 37 °C (close in-vivo conditions). The mechanical properties extruded filaments compared against bulk material, i.e. along filaments. In both cases, caused only negligible detrimental non-cyclic (less than 10 % difference ultimate strength), suitability using components applications usually exposed loading. For tests with constant amplitude, larger residual deformation (>100 greater) energy dissipation (>15 found solution as opposed laboratory conditions (air temperature), many studies. This may be due plasticisation effects water temperature. incrementally increasing amplitudes, vast majority happened last two cycles prior failure, polymer approached yield point. demonstrate importance an appropriate methodology applications; otherwise, overestimated. • Combined environmental factor studied polylactide. Less was Submerged plasticised PLA 50 reduction strength. allowed higher energy-loss