Soluble

thermally stable phthalazinone-containing poly(ether nitrile ketone ketone)s (PPENKK) have been synthesized by the nucleophilic displacement reaction of five kinds of phthalazinone_containing monomers with 2

6-dichlorobenzonitrile (DCBN) and bis-1

4-(4-fluorobenzoyl)benzene (BFBB).The polymerization reactions were conducted in sulfolane in the presence of K2CO3 to give high molecular weight polymers with intrinsic viscosities of 0.51～1.15 dL\5g-1.The structure of polymers obtained was characterized by FT-IR.The polymers showed amorphous nature as determined by wide angle X-ray diffraction (WAXD) and were readily soluble in a variety of polar sovents at room temperature

such as N-methyl-2-pyrrolidone (NMP)

N

N-dimethylacetamide (DMAc)

N

N-dimethylformamide (DMF)

chloroform

and so on

and could be easily cast into flexible and transparent films

which could be ascribed to the kink non-coplanar structure and ether linkages in the main chain.Moreover

the polymers exhibited outstanding thermal properties.The glass transition temperatures were from 252℃ to 294℃

and the temperatures for 10% weight loss in nitrogen were above 457℃.