Precise Tailoring 3D Printed In Situ Toughening Low-k Microwave Transparent Structure via Thiol-acrylate Chain...

Area of Science:

• Materials Science
• Polymer Chemistry
• Additive Manufacturing

Background:

• Triazine resins possess unique electromagnetic properties suitable for low-dielectric (low-k) materials.
• However, their poor printability and brittleness limit practical engineering applications.
• Existing plasticization methods often degrade essential dielectric and mechanical performance.

Purpose of the Study:

• To develop a novel in situ toughening strategy for triazine-based resins.
• To enable Digital Light Processing (DLP) printing of robust, low-k materials.
• To overcome the limitations of conventional plasticization techniques.

Main Methods:

• An in situ thiol-acrylate chain transfer-mediated toughening approach was employed.
• A triazine resin system with isobornyl acrylate (IBOA) and polysulfide rubber (PSR) was formulated.
• The resin was optimized for low viscosity (<150 cP) and high photosensitivity for DLP printing.

Main Results:

• The optimized resin achieved 50 µm resolution printing with a low dielectric constant (ε' = 2.66).
• The toughened material exhibited a 462.4% increase in elongation at break and a 640.5% improvement in toughness.
• High tensile strength (45.7 MPa) was maintained alongside enhanced flexibility.
• A printed gyroid lattice structure demonstrated 92% transmittance at 10 GHz.

Conclusions:

• The developed toughening strategy successfully addresses the printability and brittleness issues of triazine resins.
• This approach enables the fabrication of high-performance, low-k materials for advanced applications.
• The optimized materials show promise for applications requiring both mechanical integrity and electromagnetic transparency.