NEW AROMATIC DIACIDS CONTAINING THE TRIFLUOROMETHYL GROUP AND THEIR POLYAMIDES

A series of new fluorinated, high-temperature polymers has been prepar ed from 1,1,-bis(p-carboxyphenyl)-2,2,2-trifluoroethanol (3FOH). This diacid was synthesized by oxidation of 1,1-di(p-tolyl)-2,2,2-trifluoro ethanol, which was obtained from p-bromotoluene and ethyl trifluoroace tate. The 3FOH was also reacted with dimethyl sulphate to yield oxy-1, 1-bis(p-carboxyphenyl)-2,2,2-trifluoroethane (3FM), and with SOCl2 to produce ,1-bis(p-chloroformylphenyl)-2,2,2-trifluoroethane (3FCl). The se two diacids, as the acid chlorides, were polymerized with six aroma tic and four aliphatic diamines to produce polyamides which had viscos ities ranging from 0.32 to 1.52 dl g(-1), thermal stabilities up to 51 8 degrees C in nitrogen and glass transition temperatures from 165 deg rees C to 337 degrees C. The dielectric constants of these polyamides ranged from 2.64 to 2.99. The 3FM- and 3FCl-containing polyamides were compared with the 6F (hexafluoroisopropylidene) analogues and found t o be somewhat less thermally stable and had equal or lower T(g)s.