1-butyl-3-methylimidazole chloride ((BMIM) Cl) modified starch/poly (butylene succinate) (PBS) blends with different anions of inorganic salts were prepared by HAAKE mixer. The compatibility and thermal behaviors including crystallinity, crystallization and melting temperature, thermal stability and mechanical properties were systematically investigated by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The results show that inorganic salts can produce a strong interaction with starch/PBS blends, which can improve the mechanical properties of starch/PBS blends, enhance the mechanical strength and elongation at break of starch/PBS blends, meanwhile, the thermal stability of starch/PBS blends decreased. The SEM images reveal that the compatibility of starch/PBS become better with the increase of inorganic salts. The melting and crystallization absorption peaks in the DSC curves show that the melting enthalpy (ΔHm), crystallinity (Xc), and crystallization temperature (Tc) of the blends decrease and the cold crystallization temperature (Tcc) increase when inorganic salts is added. Moreover, inorganic salts with smaller anionic radius have much better effects on the starch/PBS blends plasticized with ((BMIM)Cl).
Keywords: anion; inorganic salts; ionic liquid; modification; poly(butylene succinate); starch.