3D printing of release-agent retaining molds

Interest in 3D-printed molds has continued to increase due to their flexible design, freeform fabrication, and rapid prototyping; however, they still rely on extra surface treatment with release agents to achieve damage-free demolding and less residual contamination. In this paper, release-agent retaining molds were achieved by vat photopolymerization of photopolymer cyanate (CE) resin with low surface tension perfluoropolyether (PFPE). The introduction of talc and nano-SiO2 here had an excellent adsorption effect on PFPE owing to their small particle size, many micropores and large surface area, which can improve the compatibility of PFPE to resin for stabilizing the hybrid over 12 h for use in 3D printing. The 3D-printed molds exhibited excellent mechanical performance with a tensile strength of 50.30 ± 1.05 MPa, modulus of 2.61 ± 0.01 GPa, and low surface energy of 19.80 ± 0.18 mJ/m2, which demonstrates their potential for damage-free demolding of soft materials, such as polydimethylsiloxane (PDMS), polyurethane (PU), and hydrogels. The molds can endure over 100 cycles of demolding without requiring the application of any extra release agents and the clearing of residual contaminations. This work represents a facile way to fabricate molds with structural complexity for damage-free demolding at low cost, high quality, and excellent durability.