Supramolecular polymers self-assembled by small molecules are a type of new material with adaptive and biocompatible properties. However, the mechanical property of these materials is always weak, impeding their applications in practice. Here, we reported that coacervation can be used to explore robust and stable bulk materials without the compromise of responsiveness. The liquid-liquid separation process could sequester and concentrate solutes, which facilitated the non-covalent association of building blocks equipped with multiple binding sites and resulted in bulk materials with versatile properties that were highly related to the encapsulated water amounts. It was a robust plastic with a remarkable Young’s modulus of 139.53 4.74 MPa when the water content was about 5% while became adhesive and could instantly self-heal with more absorbed water. Moreover, the material was reusable and fully recyclable. Our findings suggest that coacervation offers a promising approach to constructing bulk materials using small molecules and new possibilities for the application of supramolecular chemistry.