Bio-Based Pentylenediamine Monomer-Based Chemical–Physical Change Mechanism of Thermo-Oxidative Aging of Long-Carbon-Chain Nylon
Year: 2026
Type: article
Abstract: Bioengineered (enzyme-enabled) glutarimide-based biobased polyamides have garnered increasing attention due to their renewable monomer availability, low cost, and high performance. However, their physicochemical aging behavior and the underlying mechanisms under realistic thermo-oxidative conditions remain insufficiently elucidated. In this work, we synthesized bio-based PA514 via melt copolymerization of pentamethylenediamine with tetradecanedioic acid and investigated its thermo-oxidative aging behavior and mechanisms under practical service conditions. Early during thermo-oxidative exposure, physical aging manifested as lamellar thickening predominates, resulting in increased yield strength and reduced elongation at break. With prolonged aging, chemical degradation processes—principally amide bond scission followed by pentamethylenediamine cyclization—reduce the number-average molecular weight and enhance chain segment mobility, concomitant with a γ-α crystalline phase transition. These findings clarify the coupled physical and chemical aging pathway of bio-based PA514 and provide a mechanistic basis for predicting performance decay and optimizing processing and composite application strategies for glutarimide (glutaraldehyde-derived) monomer–based polyamides.
Authors: Minghui Wu, Wentao Zheng, Kejian Yang, Lu Yang, Yunqi Xu, Jinlian Fan, Mingtao Wu, Rui Chen, Jun Peng, Cheng Wang, Xudong Chen
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7140199290