Noncoplanar rigid-rod aromatic polyhydrazides containing Tröger's base.

A new Tröger's base-containing aromatic dihydrazide, 2,8-bis(carboxylic)-6H, 12H-5,11-methanodibenzo-[b,f] [1,5]-diazocine dihydrazide, was prepared by the condensation of ethyl p-aminobenzoate with hexamethylenetetramine in the presence of trifluoroacetic acid, followed by converting to the dihydrazide with a high yield and high purity. A series of novel aromatic polyhydrazides were prepared from the Tröger's unit containing dihydrazide and various aromatic diacyl chlorides via low-temperature solution polycondensation in quantitative yields. All the polyhydrazides were amorphous and readily soluble at room temperature in polar organic solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone. These polymers could be solution cast into transparent, tough, and flexible films with good mechanical properties. They had useful levels of thermal stability associated with good glass transition temperatures (163-172°C), 10% weight-loss temperatures in excess of 460°C, and char yields at 800°C in nitrogen higher than 39%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]