Crosslinked copolymer with low dielectric constant and dissipation factor based on poly(2,6‐Dimethylphenol‐co−2,6‐Diphenylphenol) and a crosslinker

ABSTRACT The crosslinked poly(2,6‐dimethylphenol (95 mol %)‐ co −2,6‐diphenylphenol (5 mol %)) (poly(2,6‐DMP 95 ‐ co −2,6‐DPP 5 )) was successfully developed as an insulating material separating conducting elements with a low dielectric constant and dissipation factor. The crosslinked poly(2,6‐DMP 95 ‐ co −2,6‐DPP 5 ) was prepared by the oxidative coupling polymerization of 2,6‐DMP with 2,6‐DPP, followed by the reaction with 4,4′‐methylenebis[2,6‐ bis (methoxymethyl)]phenol (MBMP) as a crosslinking agent. The crosslinked poly(2,6‐DMP 95 ‐ co −2,6‐DPP 5 ) exhibited a good thermal stability and glass transition temperature. The dielectric constant and dissipation factor of the crosslinked poly(2,6‐DMP 95 ‐ co −2,6‐DPP 5 ) were 2.6 and 0.004 at 10 GHz, respectively. Moreover, a flexible double layer copper clad laminate based on the crosslinked poly(2,6‐DMP 95 ‐ co −2,6‐DPP 5 ) composite was successfully prepared, indicating a useful material for high‐speed and high‐frequency electrical applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54 , 3218–3223