Effect of Macromolecular Structure on Phase Separation Regime in 3D Printed Materials.

In this study, we demonstrate the fabrication of three-dimensionally (3D) printed polymer materials with controlled phase separation using polymerization induced microphase separation (PIMS) via photoinduced 3D printing. While many parameters affecting the nanostructuration in PIMS processes have been extensively investigated, the influence of the chain transfer agent (CTA) end group, i.e., Z- group, of macromolecular chain transfer agent (macroCTA) remains unclear as previous research has exclusively employed trithiocarbonate as the CTA end group. Herein, we explore the effect of macroCTAs containing four different Z- groups on the formation of nanostructure of 3D printed materials. Our results show that the different Z- groups lead to distinct network formation and phase separation behaviors between the resins, influencing both the 3D printing process and the resulting material properties. Specifically, less reactive macroCTAs towards acrylic radical addition, such as O-alkyl xanthate and N-alkyl-N-aryl dithiocarbamate, result in translucent and brittle materials with macrophase separation morphology. In contrast, more reactive macroCTAs such as S-alkyl trithiocarbonate and 4-chloro-3,5-dimethylpyrazo dithiocarbamate produce transparent and rigid materials with nano-scale morphology. Our findings provide a novel approach to manipulate the nanostructure and properties of 3D printed PIMS materials, which could have important implications for materials science and engineering. This article is protected by copyright. All rights reserved.