Poly(phenylene sulfide) derivatives as ultralow dielectric loss materials with stable frequency response

Abstract With the recent high-speed telecommunication technologies, polymers with low dielectric constants ( D k ) and low dissipation factors ( D f ) have been in demand. However, the lack of rational molecular designs simultaneously satisfying both low D k and low D f hinders further exploration of low-dielectric polymers. Herein, we present a class of sulfur-containing aromatic polymers, namely poly(phenylene sulfide) (PPS) derivatives, as a promising family satisfying ultralow dielectric loss. In particular, poly(2,6-dimethyl-1,4-phenylene sulfide) (PMPS) exhibits an exceptionally low D f (0.00087) at 10 GHz due to its amorphous nature and the small dipoles of the sulfide groups, while exhibiting a low D k (2.80) despite the presence of polarizable sulfur. What is more, the alternating PMPS-poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) copolymer anomalously maintains robust low dielectric properties over a wide frequency range, featured by a low D k (~2.7) and an ultralow D f (<0.002) even in 10–80 GHz. Comprehensive investigations revealed that these stable dielectric properties originated from a sulfur-oxygen alternating sequence, leading to the biased dipoles satisfying intermolecular electrostatic interactions, thereby preventing molecular motions even at higher frequencies.