Antiresonance Stabilization of Wholly Aromatic Bioplastics Using a Heteroelement Booster for Superthermostable Flexible Insulators

Wholly aromatic polymers, exemplified by polybenzimidazoles (PBI), exhibit an advantageous macromolecular configuration suitable for the development of exceptionally stable and lightweight plastics. The strategic formulation of such plastics holds the potential to surmount the intrinsic instability observed in conventional plastic materials. Notably, endeavors have been undertaken to augment the functional versatility and application scope of PBI by introducing a diverse range of functionalities into its monomeric backbone. Nevertheless, these modifications have concurrently manifested an adverse impact on the inherent thermal stability of PBI. In order to address this issue, a minimal modification using a heteroelement booster was made to the PBI backbone, aimed at improving its performance without compromising its inherent properties. This modification entailed the substitution of a limited number of −NH– units with −S–, strategically interrupting resonance effects and fostering enhanced interchain interactions. The ensuing copolymers were synthesized using ecofriendly, biobased procedures, yielding cast films demonstrating an exceptional 10% mass loss temperature of 768 °C and superquick self-extinguishment. Moreover, these films exhibited remarkable mechanical toughness and outstanding dielectric performance even under elevated temperatures, suggesting their potential as ceramic-substitutable insulators in high-power turbines and next-generation electronic communication systems.