Degradation behavior of nylon 4 in the presence of newly synthesized thermal stabilizers

Three kinds of thermal stabilizers for nylon 4 were synthesized to incorporate both hindered amine groups and methylene units with various lengths. It is expected that the hindered amine groups play a role in the capture of degradation-triggering species. Considering sequence rules, hydrogen bonding formed between nylon 4 and the stabilizers is optimized to alter the lengths of the methylene units in the stabilizers. As a result, it was found that a tetramethylene unit in the stabilizer is an optimal length for hydrogen bonding in terms of isothermal thermogravimetric analysis (TGA). Considering the slight and often negligible improvement of thermal stability of nylon 4 containing commercially-available nylon 6 stabilizers, retardation of thermal degradation has been substantially improved upon.