Design of polyarylates containing tert‐butyl cyclohexyl bulky side group with high transparency and low dielectric properties

Abstract A new kind of novel low dielectric constant ( D k ) and high transparency polyarylate had been synthesized through interfacial polycondensation with 1,1′‐ bis (4‐hydroxybenzene)‐4‐tert‐butylcyclohexane (Bt‐BPZ) containing tert‐butyl cyclohexyl bulky side group. As we expect, that the introduction of tert‐butyl cyclohexyl with large free volume is proved to be an efficient strategy for obtaining low dielectric constant and high transparency polyarylate. The optimal dielectric property is obtained with 90% Bt‐PZA in polyarylate (Bt‐PZA91), which show a D k as low as 2.14 at 1 MHz. Meanwhile, Bt‐PZA91 also demonstrates good transmittance of 81.08%–88.34% at 450 nm and 78.67–88.26 at 400 nm. The cut‐off wavelength of Bt‐PZA91 is 304 nm, which is 16 nm shorter than commercial product U‐100 ( λ c : 320 nm). In addition, the resultant polyarylates showed good comprehensive performance such as T g of 202.2–220.5°C, T d 5% (the initial thermal degradation temperature) of 455.4–468.4°C, tensile strength of 64.7–86.8 MPa and low water absoption (0.41% of Bt‐PZA91). Also it was found to can be thermal process, that its convenient thermoplastic processability makes it a great candidate for light‐electronic industry, 5G communication, and we believe that Bt‐PZA will have a broad application prospect.