Synthesis and characterization of new polyamides and polyimides prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]adamantane

In this work, we synthesized a new diamine containing a pendant adamantane group and a flexible aryl ether unit, 2,2-bis[4-(4-aminophenoxy)phenyl]adamantane ( BAPA ) in three steps starting from 2-adamantanone. A series of new polyamides having inherent viscosities of 0.72–0.90 dL·g^–1 were prepared by direct polycondensation with aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents. All polymers revealed an amorphous nature and were almost readily soluble in a variety of polar solvents. The glass transition temperature of these polyamides range from 254–294°C. The polyamides remain fairly stable up to a temperature around 450°C and lose 10% weight between 490 and 524°C in nitrogen atmosphere. A series of new polyimides were also synthesized from BAPA and various aromatic tetracarboxylic dianhydrides by the conventional two-step method. The inherent viscosities of polyimides were in the range of 0.66–0.77 dL·g^–1. The polyimides are amorphous and have glass transition temperatures between 276 and 310°C. Thermogravimetric analyses demonstrated that almost all polymers are stable up to 450°C, and the 10% weight loss temperatures were recorded in the range of 515 to 541°C in nitrogen.