Microbially Derived P-Aminobenzoic Acid for Poly(p-Benzamide) Whiskers: the Influence of Monomer Synthetic Routes on Crystallization and Thermal Behavior

Polymers have long contributed to energy reduction through lightweight design, yet reinforcement strategies often rely on inorganic fillers that increase density and compromise interfacial compatibility. Extending the intrinsic advantages of polymers therefore requires organic reinforcing phases that preserve low density while providing effective load transfer. Aromatic polyamide whiskers, formed via reaction-induced crystallization, offer a promising solution owing to their high crystallinity, anisotropic morphology, and organic composition.Here, we report bio-derived poly(p-benzamide) (PBA) whiskers synthesized from microbially produced p-aminobenzoic acid (pABA) and directly compare them with whiskers prepared from petroleum-derived monomers under identical processing conditions. The results show that the differences between the two systems are generally subtle and may arise from differences in synthetic routes, although slight variations in crystallization behavior, surface morphology, and thermal decomposition were observed under identical conditions.Quantitative analysis indicates that these differences are not uniform across all crystallographic directions or properties.These observations suggest that multiple factors may influence crystallization behavior, although the exact origin cannot be unambiguously determined within the scope of this study.