Synthesis of All Aromatic Poly(Thioether-Ketone)s, Sulfur-Containing High Performance Polymers with High Solubility

Abstract

Novel aromatic poly(thioether-ketone)s (PTEKs) bearing the 2,6-dimethyl-1,5-naphthylene unit were synthesized by the polycondensation of aromatic dihaloketones and aromatic dithiols in the presence of K2CO3. High molecular weight ( Mn∼ 65 000, Mw∼ 350 000) PTEKs were obtained in quantitative yields. The molecular weight and yield of PTEK obtained from dichloroketone and dithiol were much higher than those of the corresponding poly(ether-ketone) obtained from dichloroketone and biphenol. The use of the fluoroketone as a monomer did not increase the Mn of PTEK. The effect of reaction conditions on the yield and the molecular weight of PTEKs was investigated. The phase-transfer-catalysed polycondensation and the polycondensation using masked dithiol and dichloroketone were also investigated. The PTEKs prepared have high solubility in ordinary organic solvents. Flexible, transparent, and strong cast films were prepared. The PTEKs had high glass transition temperatures (PTEK-1, 245°C and PTEK-2, 215°C) and 5% weight loss temperatures (PTEK-1, 435°C and PTEK-2, 436°C).