Aliphatic amidediol and glycerol as a mixed plasticizer for the preparation of thermoplastic starch

Abstract

The synthesis of 2-hydroxy-N-[2-(2-hydroxy-propionylamino)-ethyl] propionamide ("aliphatic amidediol") is described. Aliphatic amidediol and glycerol were used as a novel mixed plasticizer for corn starch to prepare thermoplastic starch. Fourier transform infrared (FT-IR) spectroscopy proved that the mixture of aliphatic amidediol and glycerol could form more stable and strong hydrogen bonds with starch molecules than glycerol alone. By scanning electron microscopy (SEM) and X-ray diffraction (XRD) it was proven that native starch granules and crystalline structures were broken and starch was plasticized. Tensile testing revealed that TPS plasticized by aliphatic amidediol and glycerol (AGPTPS) showed a better mechanical properties than TPS plasticized by glycerol (GPTPS). Furthermore, the water resistance of AGPTPS was better than that of GPTPS. In addition, dynamic mechanical thermal analysis (DMTA) showed that both storage modulus and glass transition temperature (T g) of AGPTPS were higher than those of GPTPS. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.