Dual Nanofillers-Reinforced Noncovalently Cross-Linked Polymeric Composites with Unprecedented Mechanical Strength

Noncovalently cross-linked polymer materials through healing, recycling, and reprocessing can reduce materials consumption and alleviate environmental pollution. However, it remains a huge challenge to fabricate super-strong noncovalently cross-linked polymer materials with mechanical strength comparable to high-performance engineering polymers. Herein, healable and reprocessable noncovalently cross-linked polymer composites with an unprecedented mechanical strength are fabricated by complexation of poly acrylic acid (PAA), polyvinylpyrrolidone (PVPON), and carbonized polymer dots (CPDs) (denoted as PAA-PVPON-CPDs). The incorporation of 15 wt % CPDs generates PAA-PVPON-CPDs composites with a tensile strength of-158 MPa and Young's modulus of-8.2 GPa. Serving as nanofillers, the CPDs can establish strong interactions with polymers in PAA-PVPON composites. The CPDs and the in situ-formed PAAPVPON nanoparticles work in concert to significantly strengthen the PAA-PVPON-CPDs composites to an unprecedented strength. The PAA-PVPON-CPDs composites exhibit excellent impact resistance and damage tolerance because of the high mechanical strength of the composites and the energy dissipation mechanism of the CPDs and PAA-PVPON nanoparticles. Moreover, the fractured PAA-PVPON-CPDs composites can be healed to restore their original mechanical strength.

Automated summary

Noncovalently cross-linked polymer materials with super-strong mechanical strength are fabricated by incorporating carbonized polymer dots (CPDs) into poly acrylic acid (PAA) and polyvinylpyrrolidone (PVPON) composites (denoted as PAA-PVPON-CPDs). The CPDs establish strong interactions with the polymers, resulting in unprecedented tensile strength and Young's modulus in the composites. The composites also exhibit excellent impact resistance and damage tolerance, and can be healed to restore their original mechanical strength.