Performance, interfacial compatibility testing and rheonaut technology analysis for simultaneous rheology and FTIR of poly(lactic acid)/modified saponite nanocomposites

Abstract

The modified saponite (SASAP) was prepared with 3-aminopropyl triethoxysilane, stearic acid, 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 1-hydroxybenzotriazole and triethylamine. The structure of SASAP was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy and static contact angle, which confirmed that SASAP had been successfully prepared. To improve the crystallization rate of poly (lactic acid) (PLA), PLA/SASAP nanocomposites was melt intercalation with SASAP as fillers. The mechanical properties showed that the elongation at break of PLA/SASAP nanocomposites was increased from 9.8% of PLA0 to 45.5%, its impact strength was increased from 9.1 kJ/m2 to 13.5 kJ/m2, and its tensile strength was increased from 23.25 MPa to 28.79 MPa. The interface tension testing demonstrated that the interface tension of PLA/SASAP nanocomposites decreased to 0.24 ( mN·m−1), which was due to the fact that amide groups of SASAP formed stronger intermolecular interactions with the PLA chains. Moreover, rotation rheology demonstrated that the interface compatibility of PLA/SASAP nanocomposites was significantly improved. Rheonaut technology analysis for simultaneous rheology and FTIR investigated the isothermal crystallization and chemical structure of PLA/SASAP nanocomposites, which indicated that SASAP accelerated the crystallization rate of PLA.