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

Noncovalentlycross-linkedpolymermaterials 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 compositeswith an unprecedented mechanical strength are fabricated by complexation of polyacrylic acid(PAA),polyvinylpyrrolidone(PVPON),and carbonized polymer dots(CPDs)(denoted as PAA-PVPON-CPDs).The incorporation of 15 wt%CPDs generates PAA-PVPON-CPDs compositeswith a tensile strength of∼158 MPa and Young’s modulus of∼8.2GPa.Servingas nanofillers,theCPDs 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.