Rational design and preparation of a strong and tough high-k material

Polyaramid is an indispensable high-performance material for its excellent thermal stability and mechanical strength . But its ultra high melting temperature which is higher than its decomposition temperature and the strong solvent resistance makes it difficult to process. In this work, we prepared a new series of soluble polyamides , poly(arylene ether naphthalene amide)s (PENA), by introducing both naphthalene and phenyl ether groups to the main chain of the polyaramid. The relationship between phenyl ether content and properties of PENAs were investigated. These PENAs have good solubility and can be made into strong and tough films by solvent casting method. Among them, poly(mono arylene ether naphthalene amide)PMENA, which contains mono-ether structure in the polymerization unit, shows the best performance with a tensile strength of 118 MPa and an elongation at break of 45%. Furthermore, PMENA also has good and stable dielectric properties with a high permittivity of 4.7, and low dielectric loss of 0.03 at 1 kHz, at room temperature .