The Effect of PDMS Incorporation on the Physicochemical Properties of Acrylate-Based Resins for SLA-Based 3D Printing

A photo-curable silicone-modified resin system based on polydimethylsiloxane (PDMS) was developed and systematically evaluated for stereolithography (SLA)-based 3D printing applications. The resin formulation consisted of bisphenol A ethoxylate dimethacrylate (Bis-EMA) and trimethylolpropane triacrylate (TMPTMA) as reactive monomers, with methacrylate-terminated PDMS (PDMS-MMA) incorporated at concentrations ranging from 0 to 15 wt%. The influence of PDMS-MMA content on key physicochemical properties relevant to SLA processing, including viscosity, mechanical performance, thermal stability, optical transmittance, and curing shrinkage, was systematically investigated. Moderate incorporation of PDMS-MMA improved the mechanical flexibility of the resin, with the tensile strength reaching a maximum value of 5.95 MPa at 5 wt% PDMS-MMA. However, further increases in PDMS-MMA content resulted in a gradual decrease in tensile strength and optical transmittance, indicating the importance of optimizing the formulation composition. Thermogravimetric analysis (TGA) indicated improved thermal stability with increasing PDMS-MMA content, while curing shrinkage decreased progressively as the PDMS fraction increased. Structural printing tests confirmed that the developed resin system exhibited stable layer adhesion and shape fidelity during SLA fabrication, enabling the successful printing of complex three-dimensional structures. These results demonstrate that PDMS-modified acrylate resins provide a promising strategy for balancing mechanical flexibility, dimensional stability, and printability in SLA-based additive manufacturing.