Evaluation of thermal and dielectric behaviour of some anionic nylon 612 copolymers

The anionic nylon 612 copolymers consisting of ϵ-caprolactam and 0.0–50.0 wt.% of laurolactam comonomer were synthesized and some of their characteristics were compared. The melting temperature, degree of crystallinity (first and second heating scan) and crystallization temperature of the nylon 612 copolymers are influenced by the presence of comonomer (laurolactam) decreasing proportionally to the amount of the laurolactam in the initial monomer mixture. The thermal stability of the copolyamides is good and equal to that of PA 6. Dielectric measurements performed on the polymers under study, over a frequency range of 100–106 Hz, at temperatures from 173 to 373 K have evidenced that modification of the dielectric permittivity and dielectric loss values occur in concordance with increase/decrease of the homogeneity in the polymer chains structure induced by incorporation of laurolactam segments.