Vat Photopolymerisation of High-Molecular-Weight Polymer Latexes: Colloidal Printability, Scaffold Formation, Coalescence and Pseudothermoplastic Reprocessing
Segurola, Juan
2026-08-27 · Report · Version 1.1
Vat photopolymerisation generally relies on low-molecular-weight monomers and oligomers because processable feedstocks must flow, refill and level within the printer. High-molecular-weight polymers provide entanglement, toughness and thermoplastic or elastomeric behaviour, but their solutions and melts commonly become too viscous for conventional VPP. Polymer latexes provide a different materials architecture: the high-molecular-weight chains are confined inside pre-existing colloidal particles, while the continuous liquid phase remains comparatively low in viscosity. In the demonstrated latex route, water-soluble monomers, oligomers or crosslinkers in the continuous phase form a temporary or permanent photocured scaffold around the particles. This scaffold fixes the printed geometry and creates a particle-embedded green body. Drying and thermal post-processing then remove the aqueous carrier and promote particle contact, deformation, interdiffusion or coagulation through the scaffold. The final material may become a semi-interpenetrating network, a true interpenetrating network or a thermoplastic-dominant hybrid whose behaviour depends on latex chemistry, scaffold fraction, particle functionality and post-processing history. Published systems now include styrene-butadiene rubber, synthetic and natural polyisoprene, waterborne polyurethane, poly(styrene- b-isoprene-b-styrene), sulfonated EPDM and high-Tg methacrylic latexes. These studies demonstrate that latex VPP can expand the accessible molecular-weight and polymer-family space, but they also expose coupled risks: scattering by the particles, colloidal instability, green-body weakness, drying gradients, large isotropic shrinkage, incomplete coalescence and persistent influence of the photocured scaffold on final properties. This review develops a state-resolved engineering framework for latex VPP. It separates the liquid colloidal feedstock, photocured green body, dried/coalesced material and any reprocessed state. It defines boundaries against polymerisation-induced phase separation, dual cure, covalent adaptable networks and generic filled-resin rheology. It also proposes minimum reporting requirements for particle state, scaffold fraction, carrier removal, directional shrinkage, coalescence, final network morphology and property retention after reprocessing.