High-Performance Methacrylate-Phenylenediamine-Epoxy Photothermal Dual-Curing Resin for Digital Light Processing

초록

High-performance polymer materials based on the dual-curing technique for vat-photopolymerization processes, particularly Digital Light Processing (DLP), have gained attention to address the poor mechanical properties of conventional photocurable resins. While dual-curing resins can improve mechanical properties, significant improvements often require increased epoxy content, resulting in higher viscosity, reduced photoreactivity, decreased processability, and lower precision of printed parts. In this study, we present a novel sequential photothermal dual-curing resin system combining bisphenol-based methacrylate and an epoxy-amine curing agent, with a reduced epoxy content. Comprehensive analyses were performed across three key stages to achieve excellent mechanical properties: the pre-process stage, involving the preparation of a dual-curing resin with an optimal viscosity for the DLP process; the additive manufacturing (AM) stage, enhanced by an additional heating system to improve processability; and the post-treatment stage. This dual-curing resin was systematically evaluated under various post-curing conditions, including green part, UV post-curing, and UV + Thermal post-curing. Following the final post-curing process, the material exhibited superior mechanical properties, achieving a tensile strength of 106.24 MPa and a glass transition temperature of 138.44 degrees C with only 30% epoxy content. Moreover, the resin's low viscosity enables a smoother printing process, facilitating the fabrication of complex geometries with high dimensional stability and a shrinkage rate of less than 1%. This study presents a systematic approach for designing high-performance dual-curing resins with reduced epoxy content, offering strong potential for advanced engineering applications requiring both strength and precision.

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