Simultaneous Toughening and Strengthening of Ductile Polymer by Rigid Polymeric Fillers: The Role of Interfacial Entanglement.

The modification of thermoplastic polymers is frequently impeded by the inherent contradiction between their toughness and strength. In this study, an effective strategy to significantly improve the mechanical properties of ductile polymers by simply adding a complimentary rigid polymer is introduced. This work uses a semi-crystalline polymer aliphatic polyketone (POK) as the matrix material and a small quantity of polymethyl methacrylate (PMMA) as the rigid polymer, through establishing molecular chain entanglements at the interface to produce POK/PMMA blends with exceptional mechanical property. The experimental study shows that PMMA as a small island phase is homogeneously dispersed in the POK matrix, while the interfacial adhesion between the POK matrix and PMMA island is enhanced by the high-density molecular chain entanglement between PMMA and the POK matrix. The strong entanglements and high concentration of PMMA domains promote uniform crazes and overall shear yielding. As a result, the POK/PMMA blend exhibits exceptional mechanical properties with notched impact strength, elongation at break, tensile strength, and Young's modulus, of 20 kJ m^-2, 326%, 60 and 2185 MPa, respectively. A universal approach is further suggested for enhancing the toughness and strength of ductile polymers using a complimentary rigid polymer.