Improved fracture toughness of dynamically vulcanized poly(vinylidene fluoride)/silicone rubber filled zinc dimethacrylate composite

The interfacial compatibility of dynamically vulcanized poly(vinylidene fluoride)/silicone rubber (PVDF/SR) composite was in-situ improved by zinc dimethacrylate (ZDMA). The dispersion of filler, as well as filler-matrix interfacial interaction, was a crucial factor to improve the fracture toughness of the composites. ZDMA was selectively distributed in the interface between the PVDF/SR, largely changing the morphology of the crosslinked SR phase. The SR particles in the PVDF/SR binary composite showed a “network-like” aggregation structure, but this structure was not observed in PVDF/SR/ZDMA composites, where a large number of fibrils with different length were observed on the fracture surface, which contributed to the improved impact strength. The Izod impact strength of PVDF/SR composite (70/30, w/w) was increased up to about 18.4 kJ/m2 by incorporation of 9 phr ZDMA, which was 3-4 times higher than the PVDF/SR composite. In addition, the rheology analysis indicated that interfacial adhesion between the PVDF and SR phases was improved due to the incorporation of ZDMA.