Strengthened Poly(vinylidene fluoride)/Epoxidized Natural Rubber Blend by a Reactive Compatibilizer Based on an Amino Acid-Modified Fluorocarbon Elastomer

The blending of poly­(vinylidene fluoride) (PVDF) and epoxidized natural rubber (ENR50) offers a large domain size distribution due to poor interfacial adhesion. In this work, a reactive compatibilizer for the PVDF/ENR50 blend was prepared based on the 6-aminohexanoic acid (AHA)-modified fluorocarbon elastomer (FKM), resulting in situ grafting reaction between the carboxylic group (−COOH) of FKM-AHA and the epoxide group of ENR50. Fourier transform infrared (FTIR) spectroscopy analysis revealed the formation of a graft copolymer between ENR and FKM-AHA, which was generated during melt mixing. At the same time, the domain size was significantly reduced from 8.3 to 2.5 μm for compatibilized blends. Therefore, the mechanical properties were also significantly improved with the addition of FKM-AHA due to the improvement of interfacial adhesion between the two phases. Moreover, rheological and DSC analyses also revealed that reactive compatibilization can improve the network structure provided by chemical interaction and physical entanglement at the interface. This work provides an effective strategy for developing PVDF/ENR-based engineered blends with improved compatibility and mechanical properties.