Role of Crystalline Structure in the Marine Biodegradation Process of Polyamide 6

Cryo-milling enhanced the biodegradation of PA6 particles by simultaneously altering their particle size, crystalline structure, and molecular weight, whereas subsequent reannealing markedly suppressed their biodegradation despite their small particle sizes. These results further support a strong contribution of crystalline structure to PA6 biodegradation while also demonstrating that the effects of crystalline structure and sample geometry are coupled.

Furthermore, the preferential degradation of less-ordered regions may leave crystalline remnants that are relatively resistant to further biodegradation and could potentially contribute to the formation of persistent nanoscale particles. However, direct characterization of such particles is required to verify this possibility and evaluate their environmental implications.