Preparation and properties of new random and block copolyamides derived from 1,3-bis(3-aminopropyl)tetramethyldisiloxane,aromatic diamines,and isophthaloyl chloride

Random and block disiloxane-containing copolyamides were prepared through one- and two-step procedures, respectively, by the low temperature solution polycondensation in chloroform containing triethylamine hydrochloride starting from 1,3-bis(3-aminopropyl)tetramethyldisiloxane, an aromatic diamine 3,4'-diaminodiphenyl ether (ODA) or m-phenylenediamine], and isophthaloyl chloride. The random copolyamides exhibited composition-dependent single glass transition temperature (T_g), and gave transparent and tough films by solution casting or hot pressing. The ODA-based block copolyamides had two T_g's, and the solvent-cast transparent films exhibited microphase separated morphology. The block copolymers gave better quality films than the single-phase random copolymers. © 1992 John Wiley & Sons, Inc.