Novel transparent poly(arylene ether nitrile) with low dielectric constant: Synthesis and characterization

The novel poly (arylene ether nitrile) copolymers P-HAD and P-PAD containing pendant aliphatic ring and -CF3 group were synthesized by 4, 4′-cyclohexane-1, 1′-diyldiphenol (CHDP) or 4, 4′-cyclopentane-1, 1′-diyldiphenol (CPDP), 4, 4′-(hexafluoroisopropylidene) diphenol and 2, 6-dichlorobenzonitrile (DCBN) through nucleophilic polycondensation using NMP as the solvent in the work. The copolymers owned the inherent viscosities of 0.269-0.868 dL g-1. They exhibited good thermal property, the glass transition temperatures (Tg) were 169.3-173.2°C, the weight-loss temperatures (T5%) were 464.2-470.2°C, and the heat resistance indexs (HRI) were 238.6-248.6°C. The copolymers’ films had good tensile strengths of 62.9-75.1 MPa. Because of the introduction of -CF3 unit, the solubility, dielectric property and optical property were improved well. The copolymers could be dissolved in some solutions at room temperature, such as NMP, DMF, CH2Cl2 and CHCl3, they can be processed by solution method. They had good dielectric property, the dielectric constants were 4.3-4.6 at about 1000 KHz. Additionally, the optical transmittance of these two copolymers were 75.2-76.3% at 450 nm, which have potential to be applied as the heat-resistant optical films in the 5G area or electronic field.