Digital light processing of multi-walled carbon nanotubes-reinforced photosensitive resin composites: Effects on microstructures and mechanical properties

Abstract

Owing to their great potential to enhance the structural, mechanical, and electrical properties of materials, numerous researchers have dedicated their efforts to manufacturing multi-walled carbon nanotubes (MWCNTs)-reinforced composites via additive manufacturing (AM) to leverage AM's ability to fabricate intricate structural components. However, there is currently limited research on MWCNTs in photosensitive resin (PR) systems processed via a type of vat photopolymerization AM technique - digital light processing (DLP). Additionally, the distribution pattern of MWCNTs in PR systems is still unknown. To address these research gaps, this investigation focuses on fabricating MWCNTs-reinforced PR (MWCNTs-PR) via DLP and studying the effects of MWCNTs content on microstructure characterizations and mechanical properties of MWCNTs-PR. These results show that PR with 0.05 wt% MWCNTs addition exhibits a 25 % increase in elastic modulus and a 2 % increase in bending strength compared to pure PR. To achieve a more uniform distribution of MWCNTs in the PR, a combination of an ultrasonic bath and mechanical stirring was adopted. To further investigate the mechanism behind MWCNTs-enhanced bending resistance, a multi-material layered 3D printing structure was developed. The experimental findings reveal that the 10001 structure yields the highest bending modulus, surpassing the control group by 14.9 %. To validate the bending resistance mechanism attributed to MWCNTs-PR, finite element analysis was conducted.