RETRACTED: The moisture absorption of 3D printed short carbon fibre reinforced polyamide

Polymer composites are commonly exposed to humid conditions and undergo reductions in mechanical properties. It is challenging to describe the moisture absorption dynamics of 3D printed parts due to manufacture-induced microstructures. This work investigates the moisture absorption of 3D printed short carbon fibre reinforced polyamide with varied microstructures and resulting influence on mechanical properties. The printed composites have inferior microstructures compared to the polyamide and diffusivity increases with the number of interlayer interfaces by up to 119 % (three times that of compression moulded composite). The microstructure is permanently aggravated by moisture resulting in more significant and irreversible reductions in yield stress (39 to 59 %) and tensile modulus (65 to 79 %) compared to injection moulded samples. Additionally, the shear modulus of printed polyamide and composites decrease by up to 63 % and 74 %, respectively. The results are helpful for prediction, evaluation, and maintenance of 3D printed applications subject to moisture environment.