Synthesis and properties of novel aromatic poly(thioether-ketone)s as sulfur-containing high-performance polymers

Novel aromatic poly(thioether-ketone)s (PTEKs) bearing the 2,6-dimethyl-1,5-naphthylene units were synthesized by the polycondensation of aromatic dihaloketones and aromatic dithiols in the presence of K2CO3. PTEKs with molecular weight (M-n similar to 65 000, M-w similar to 350 000) were obtained in quantitative yields. The molecular weights and yields of PTEKs obtained from aromatic dichloroketone and aromatic dithiols were much higher than those of the corresponding poly(ether-ketone)s (PEKMNs) obtained from aromatic dichloroketone and biphenols and were nearly the same as those of PTEKs obtained from aromatic difluoroketone and aromatic dithiols. The effect of reaction conditions on yield and molecular weight of PTEKs was investigated. The PTEKs had high solubility in ordinary organic solvents. Flexible, transparent, and strong films were cast from CHCl3 solution. PTEK-1 and PTEK-2 had high glass transition temperatures (T-g; PTEK-1 245 degreesC, PTEK-2 215 degreesC) and 5% weight loss temperatures (T-d5; PTEK-1 435 degreesC, PTEK-2 436 degreesC).