Symmetrical “sandwich” polybutadiene film with high-frequency low dielectric constants, ultra-low dielectric loss and high adhesive strength

To solve film formation and creep of non-vulcanized 1, 2-polybutadiene, it was designed and fabricated as a thermosetting, transferable and symmetrical “sandwich” structure adhesive film through solution coating processing. The adhesive failure evolved from an independent cohesive failure or interfacial failure to a randomly staggered interfacial failure. According to the molecular dynamic simulation, compared to the molecular structure of 1,4-polybutadiene, the isolated π electron cloud of the vinyl-side chain of 1,2-polybutadiene can form “chemical-like bonding” with the outer electrons of copper atoms. Meanwhile, Peel strength of the surface-modified polybutadiene adhesive (28.16 N/25mm) was about three times that of the untreated one (10.11 N/25mm), and its dielectric properties (e'=2.416, tanσ=0.0026) maintained an ultralow level at 10 GHz, which mainly decided by the electronic and atomic polarization of vinyl. This strategy was helpful to develop a processing method for adhesive film of non-vulcani...