Acid-Adaptive Polymers Capable of Proton-Capturing and Matrix-Strengthening

Biological systems exhibit a remarkable ability to turn destructive environmental stressors into constructive factors for adaptation and survival-a capability rarely observed in engineering materials. Conventional polymers, for instance, degrade in acidic environments as chemical bond cleavage leads to significant loss of stiffness and strength. In contrast, acid-resistant bacteria such as Escherichia coli and Lactococcus lactis neutralize protons and undergo biochemical adaptations to withstand acidity.

Inspired by natural acid adaptation, we develop an acid-adaptive polymer with exceptional acid resistance and a unique acid-triggered mechanical restoration behavior.

By incorporating sodium carboxylate and amino functional groups, the polymer effectively neutralizes protons, mitigating acid-induced degradation. Besides, invading acids facilitate amidation reactions at temperatures as low as 40°C, forming secondary crosslinks within the polymer matrix.

This process enhances the material's stiffness and strength by 119% and 101%, respectively.

With its dual functionality of proton neutralization and strength restoration, this polymer offers a transformative solution for defense, chemical processing, and automotive applications requiring durability in harsh acidic environments.