High Performance Polyamides based on s-Triazine Ring: Synthesis and Characterization

Abstract

High-performance polymers based on aromatic rings are desirable not only because of the high primary bond strengths, but also because their rigid (stiff) polymer chains offer increased resistance to deformation and thermal softening. The choice of s-triazine nucleus is based on its high thermal stability derived from its molecular symmetry and aromaticity. It is well known that s-triazine is heat resistant. Modification of monomer structures by introduction of aromatic pendent groups or heterocyclic rings into the polymer backbone provides good solubility and thermal stability. A new set of polyamides with —CO—NH— groups were synthesized by the Yamazaki’s phosphorylation reaction 2-(morpholino)-4,6-bis (6-napthoxy-2-carboxy)-s-triazine with various aromatic diamines. The polyamides had inherent viscosities in the range 0.549—0.685 dL g^-1 in dimethylformamide at room temperature (30 ^°C) and density 1.135—1.208 g cm ^{- 3} . All the polyamides showed good thermal stability and most of them were readily soluble at room temperature in polar solvents such as N,N-dimethylacetamide, 1-methyl-2-pyrrolidone and dimethylformamide. Polyamides were synthesized successfully with the favourable properties of higher thermal stability along-with good processibility.