Microgravity Effects on Photopolymer Cure: Convection, Bubbles, Sedimentation, Interfaces and Network Uniformity

Microgravity modifies photopolymerisation primarily by changing transport and boundary conditions around a reaction that still depends on light, chemistry and heat. Natural convection is suppressed, sedimentation and buoyant bubble migration are reduced, capillary forces gain relative importance and reaction heat can accumulate locally. Historical microgravity polymerisation studies and recent in-space photopolymer experiments show that these effects can either reduce gravity-driven gradients or create new thermal and interfacial defects. This review defines the variables required to distinguish chemical kinetics from gravity-dependent transport and to qualify network uniformity in photocurable systems. ER-444.