Tough hyperbranched polyaryletherketone-based photosensitive resins bearing excellent dielectric property and thermal resistence

Organic polymer materials with low dielectric properties have garnered significant attention due to their convenient preparation process, low cost, and commendable mechanical properties. Such polymers, especially with heteromorphic structures, exhibited great potential for future electronic devices and antennas, particularly accompanied with rapid manufacturing technologies like three-dimensional (3D) printing. In this study, a series of new allyl ether-ended hyperbranched fluorene-based polyaryletherketone (hb-PFAEK-Allyls) were developed. The content of allyl ether photosensitive groups and molecular weight were controlled by adjusting the molar ratio of OH:F loading. UV-curable resins were then prepared through blending between hb-PFAEK-Allyls with trimethylolpropane triacrylate (TMPTA) and ethylene glycol bis(3-mercaptopropionate) (EGBMP), resulting in thiol-allyl-acrylate ternary UV-cured system. The influence of molecular weight of the hyperbranched polymers on the thermal performance, mechanical properties, and dielectric properties of the UV-cured films was systematically investigated. The results show that due to the introduction of hyperbranched structure with high molecular weight, the Tg of the UV-cured film can reach up to 248 °C. Due to the increased molecular free volume in the hyperbranched structure, the dielectric constant of the UV-cured film can be reduced to as low as 2.74 at 1 GHz. Due to the design of thiol-allyl-acrylate ternary UV-cured system, the cured film has excellent mechanical properties, with the highest tensile strength of 61.0 MPa and the elongation at break of 7.0%. This study represents innovative progress on integrating fully aromatic-based photosensitive hyperbranched polyaryletherketone into UV-curable resin architecture. Overall, the herein hb-PFAEK-Allyls-based photosensitive resins exhibit outstanding comprehensive performance and holds great potential for application in advanced 3D printing technology.