Synthesis and crosslinking reaction of a novel polymer containing benzoxazine and phenyleneethynylene moieties in the main chain

Abstract

ABSTRACTA novel polymer, poly(1) containing benzoxazine and phenyleneethynylene moieties in the main chain with number‐average molecular weights ranging from 1400 to 9800 was obtained quantitatively by the Sonogashira–Hagihara coupling polymerization of the corresponding iodophenyl‐ and ethynylphenyl‐substituted monomer1. Poly(1) was heated at 200 °C under N2for 2 h to obtain the cured polymer, poly(1)′ via the ring‐opening polymerization of the benzoxazine moieties. The structures of the polymer before and after curing were confirmed by1H‐NMR, IR, and UV–vis absorption and reflectance spectroscopies. Poly(1)′ was thermally more stable than monomer1and poly(1). A specimen was prepared from a mixture of poly(1) and phenol‐diaminodiphenylmethane type benzoxazine2by heating at 200 °C for 2 h under N2. The poly(1)/2resin was thermally stable than bisphenol‐A type benzoxazine resin3. Poly(1) exhibited XRD peaks corresponding to thed‐spacings of 1.26–0.98 and 0.40 nm, assignable to the repeating monomer unit and alignment of polymer molecules, respectively. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2019,57, 2581–2589