PREPARATION AND PROPERTIES OF NEW SOLUBLE AROMATIC POLYIMIDES FROM 2,2'-BIS(3,4-DICARBOXYPHENOXY)BIPHENYL DIANHYDRIDE AND AROMATIC DIAMINES

A new aromatic tetracarboxylic dianhydride having a crank and twisted noncoplannar structure, 2,2'-bis(3,4-dicarboxyphenoxy)biphenyl dianhyd ride, was synthesized by the reaction of 4-nitrophthalonitrile with bi phenyl-2,2'-diol, followed by hydrolysis and cyclodehydration. The bip henyl-2,2'-diyl-containing aromatic polyimides having inherent viscosi ties up to 0.66 dL/g were obtained by the conventional two-step proced ure starting from the dianhydride monomer and various aromatic diamine s. Most of the polyimides were readily soluble in amide-type solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone. The aromatic polyimides had glass transition temperatures in the range of 205-242 degrees C, and began to lose weight around 415 degrees C, with 10% wei ght loss being recorded at about 500 degrees C in air. (C) 1998 John W iley & Sons, Inc.