Facile preparation of recyclable cyclic polyolefin/polystyrene vitrimers with low dielectric loss based on semi-interpenetrating polymer networks for high-frequency copper-clad laminates

With the rapid development of the fifth-generation mobile communication, stringent requirements have been put forward for the dielectric properties of polymer-based copper-clad laminates. However, thermally and mechanically robust materials with low dielectric loss (Dr) are very scarce. Herein, we propose a simple method to prepare cyclic polyolefin (COC)/polystyrene vitrimers (PSVMs) from semi-interpenetrating polymer networks with low Dr. The topological rearrangement of PSVMs caused by the transesterification of nitrogen-coordinating cyclic boronic ester (NCB) linkages under heat helped uniformly disperse the COC in the PSVM. As a result, the COC-PSVM and its quartz glass fiber reinforced COC-PSVM composites exhibited excellent thermal, mechanical, and dielectric properties. Specifically, the dynamic reversibility of the NCB linkages under heat facilitated the complete recovery of the COC-PSVM composites. This study provides a new strategy for the preparation of resin matrix with low Dr for printed circuit boards, which is conductive to reducing the environmental pollution from e-waste.