UV-induced disulfide metathesis: Strengthening interlayer adhesion and rectifying warped 3D printed materials

Abstract

UV-curing 3D printing technology has greatly facilitated the development of manufacturing industry. However, there still are some crucial drawbacks to UV-curing 3D printed materials, i.e., the anisotropic mechanical strength, curing shrinkage and warpage. Herein, UV-induced disulfide metathesis able to rearrange the crosslinked network is adopted to overcome these difficulties. A disulfide bond-containing acrylate (MA-SS) is synthesized and incorporated into a 3D printing photosensitive resin. The photopolymerization kinetics indicate that the moderate amount of MA-SS can promote the photopolymerization conversion, while excessive MA-SS will decrease the conversion. The MA-SS can also greatly improve the tensile strength of 3D printed materials, owing to the more homogenous crosslinked networks and higher crosslinking density. Moreover, the anisotropic tensile strength between x- and z- axis is greatly reduced by the MA-SS, since disulfide metathesis can enhance the adhesion between printing layers. Furthermore, the 3D printed materials can be reversibly transformed from one shape to another by virtue of UV-induced disulfide metathesis. More importantly, the seriously warped 3D printed materials can be effectively rectified under the action of UV irradiation, where the warpage is significantly decreased from 6% to 1–2%. Therefore, this facile strategy of rearranging the crosslinked networks can conquer the drawbacks within UV-curing 3D printing materials to fulfill high-precision 3D printed materials. • UV-induced disulfide metathesis is conducive to better 3D printed materials. • UV-induced disulfide metathesis enhances interface adhesion among printing layers. • The warped 3D printed materials can be rectified by UV-induced disulfide metathesis. • The 3D printed materials can be reversibly transformed under UV irradiation.