Synthesis and properties of aromatic phthalazinone-containing poly(aryl ether nitrile ketone)s and its application in insulating coatings

Soluble,thermally stable aromatic poly(phthalazinone ether nitrile ketone)s(PPENK) have been synthesized by the nucleophilic displacement reaction of four kinds of phthalazinone-containing bisphenol-like monomers with 2,6-dihalobenzonitrile and 4,4'-diflurodiphenylketone,respectively.The structures of polymers were characterized by FT-IR spectra.The inherent viscosities of these PPENKs were in the range of 0.50 to 1.17dL/g.All the PPENKs were amorphous,and showed good solubility in a variety of polar non-protonic solvents such as chloroform,N-methyl-2-pyrrolidone(NMP),and N,N-dimethylacetamide(DMAc) at room temperature,which made it possible to easily cast them into flexible and transparent films.They had useful levels of thermal stability associated with glass transition temperature in the range of 255 to 277℃,10% weight-loss temperature in excess of 498℃ in nitrogen.These soluble PPENKs were applied to prepare insulating coatings.The insulating coatings of PPENKs exhibited high mechanical strength,good flexibility and adhesion,and favorable electro-insulating property.