High Performance Polymers, 2nd Edition

12: PARTIALLY AROMATIC POLY(AMIDE)S 283

to improve the barrier properties in PPAs [15]. A pro-

cess for the manufacture of MXDA-containing poly-

mers has been described [17]. MXDA finds use both

in amorphous types [12] and crystalline types [18].

12.2 Polymerization and

Fabrication

Generally, PAs are produced by the dehydrating

polycondensation of a diamine monomer and a dicar-

boxylic acid monomer.

12.2.1 Conventional Route

Conventional techniques for the polycondensation

of PAs employ an aqueous solution of ingredients.

Polymerization is accomplished by the gradual

removal of the water from the mixture at elevated

pressures by gradually increasing the temperature of

the reaction medium. In this manner, the majority

of the water is removed and the temperature ...