Polymeric materials reinforced by noncovalent aggregates of polymer chains

Mechanical performances are among the most fundamental properties that dictate the applicability and durability of polymeric materials. Reinforcement of polymeric materials is eternally pursued to broaden the applications of polymers with light-weight, low-cost and easy-processing advantages. Noncovalent aggregates of biomacromolecules have been found to play a significant role in the mechanical properties of many natural materials, such as the spider silk. Increasing numbers of reports have demonstrated that the in situ formed noncovalent aggregates of polymer chains in polymeric systems are highly effective for enhancing the mechanical properties of artificial polymeric materials, in terms of strength, stiffness, toughness, and/or elasticity. The in situ formed noncovalent aggregates act as additional crosslinking domains and well-dispersed "hard" nanofillers in the polymer networks, significantly strengthening, stiffening and/or toughening the polymeric materials. Moreover, the noncovalent crosslinking of polymer chains favors the development of healable and recyclable polymeric materials, thanks to the reversible and dynamic properties of noncovalent bonds. This review provides an overview of the recent advances on the enhancement of the mechanical properties of different polymeric materials by the in situ formed noncovalent aggregates of polymer chains. It is expected to arouse inspirations for the development of novel polymeric materials with extraordinary mechanical performances and functionalities.