Effect of ethylene-acrylate-(maleic anhydride) terpolymer on mechanical properties and morphology of poly(ethylene terephthalate)/polyamide-6 blends

BACKGROUND: Poly(ethylene terephthalate) (PET)/polyamide-6 (PA-6) blends are promising for engineering and food-packaging applications. However, their poor toughness limits their use. In this study, an ethylene-acrylate-(maleic anhydride) terpolymer (E-AE-MA) was added to PET/PA-6 blends in order to improve the toughness. RESULTS: Izod impact tests indicated an excellent toughening effect of E-AE-MA. E-AE-MA particles were observed to be selectively dispersed at the interface between PET and PA-6 phases and in the domain of the PA-6 phase. Fourier transform infrared spectroscopy and differential scanning calorimetry results demonstrated that the formation of E-AE-MA layers around PA-6 particles cut off the interaction between PET and PA-6, resulting in an enlarged PA-6 phase domain. CONCLUSION: Based on the experimental results, a core-shell microstructure, with PA-6 as a hard core and E-AE-MA as a soft shell, could be suggested. The formation of this core-shell microstructure, along with the increased PA-6 phase domain size, is the main toughening mechanism of E-AE-MA in PET/PA-6 blends. (c) 2007 Society of Chemical Industry.