3D Printing Latex: A Route to Complex Geometries of High Molecular Weight Polymers Philip J. Scott Viswanath Meenakshisundaram Maruti Hegde Christopher R. Kasprzak Christopher R. Winkler Keyton D. Feller Christopher B. Williams Timothy E. Long 10.1021/acsami.9b19986.s003 https://acs.figshare.com/articles/media/3D_Printing_Latex_A_Route_to_Complex_Geometries_of_High_Molecular_Weight_Polymers/11879151 Vat photopolymerization (VP) additive manufacturing fabricates intricate geometries with excellent resolution; however, high molecular weight polymers are not amenable to VP due to concomitant high solution and melt viscosities. Thus, a challenging paradox arises between printability and mechanical performance. This report describes concurrent photopolymer and VP system design to navigate this paradox with the unprecedented use of polymeric colloids (latexes) that effectively decouple the dependency of viscosity on molecular weight. Photocrosslinking of a continuous-phase scaffold, which surrounds the latex particles, combined with in situ computer-vision print parameter optimization, which compensates for light scattering, enables high-resolution VP of high molecular weight polymer latexes as particle-embedded green bodies. Thermal post-processing promotes coalescence of the dispersed particles throughout the scaffold, forming a semi-interpenetrating polymer network without loss in part resolution. Printing a styrene-butadiene rubber latex, a previously inaccessible elastomer composition for VP, exemplified this approach and yielded printed elastomers with precise geometry and tensile extensibilities exceeding 500%. 2020-02-20 19:09:49 weight polymers part resolution Complex Geometries VP system design Thermal post-processing weight polymer latexes elastomer composition continuous-phase scaffold styrene-butadiene rubber latex additive manufacturing semi-interpenetrating polymer network paradox High Molecular Weight Polymers Vat photopolymerization 3 D Printing Latex latex particles computer-vision print parameter optimization