Effects of hygrothermal aging on the physicochemical and mechanical properties of 3D-printed PA6

Abstract

This paper investigates the effects of hygrothermal aging on PA6 filaments used as raw material in fused filament fabrication (FFF). The filaments were subjected to various aging conditions to evaluate their physicochemical and thermomechanical properties. The results show that water was uniformly absorbed at all aging temperatures, although the kinetics of absorption varied. The introduction of water caused an increase in chain mobility, resulting in a decrease in the glass transition temperature, crystallinity, Young’s modulus, tensile strength, and yield strength. These changes in properties followed a consistent trend, with an initial rapid decrease followed by stabilization at a minimum value common to all temperatures. Notably, elongation at break increased sevenfold at the highest temperature. Compared to samples printed with unaged filaments, those produced with aged filaments exhibited a decrease in mechanical properties.