3d Printing of High Viscosity UV-curable Resin for Highly Stretchable And Resilient Elastomer.

Abstract

Vat photopolymerization prepared elastomers usually exhibit unsatisfied mechanical properties due to their insufficient growth of molecular weight upon UV exposure. Increasing the weight ratio of oligomer in the resin system is an effective approach to enhance the mechanical properties, yet the viscosity of the UV-curable resin increased dramatically which makes it difficult to be used. Here, a linear scan-based vat photopolymerization (LSVP) system which can print high-viscosity resin was carried out to 3D print the oligomer-dominated UV-curable resin via a dual-curing mechanism. Briefly, a polyurethane methacrylate blocking (PUB) oligomer is first synthesized and then mixed with a commercialized bifunctional oligomer, photoinitiator, and primary amine as a chain extender to prepare high-viscosity UV-curable resin for LSVP system. Through thermal treatment, deblocked isocyanate is further crosslinked with a chain extender to construct a highly entangled polymer chain network. The optimal thermal treatment parameters are investigated. Simultaneously, the resilience of the 3D-printed elastomer was evaluated by continuous tensile loading and unloading tests. Subsequently, complex structured elastomers were printed, exhibiting favorable mechanical durability without defects. The results obtained from this work will provide a reference for preparing elastomeric devices with excellent physical properties and expand the application fields of vat photopolymerization. This article is protected by copyright. All rights reserved.