Synthesis Of Aliphatic Amidediol And Study On Starch Thermoplasticization

Starch, a natural renewable polysaccharide obtained from a great variety of crops, is one of the promising raw materials for the production of biodegradable plastics. The plasticizer has important influence on plasticization of starch, and different plasticizer also has important influence on the TPS. In text, based on the advantages and disadvantages of plasticizer such as polyols and amides, the plasticizer which contains hydroxyl group and amine group was designed. And it was systematic studied on the starch plasticization.A series of aliphatic amidediol was synthesized using DL-lactic acid, glycolic acid, thioglycolic acid andε-caprolactone to react with ethylenediamine, 1, 3-propane diamine and 1, 6-hexanediamine without solvent and catalyst. Ten products were synthesized and charactered by m.p., FT-IR and 1H NMR, and the influencing factors on the reaction yields were also discussed. This method provided several advantages such as being environmentally friendly, processing high yields and simple work-up procedure, thus it was a green method.Aliphatic amidediol was synthesized and mixed with glycerol as a novel mixed plasticizer for corn starch (AGCTPS) and potato starch (AGPTPS) to prepare thermoplastic starch. The interaction between aliphatic amidediol/glycerol and starch was investigated using Fourier transform infrared (FT-IR). FT-IR proved that the mixture of aliphatic amidediol and glycerol could form more stable and strong hydrogen bonds with starch molecules than the conventional plasticizer, glycerol. By scanning electron microscope (SEM) native starch granules were proved to transfer to a continuous phase. The mechanical properties and starch retrogradation behavior were also studied by tensile testing and X-ray diffraction (XRD), respectively. The water resistance of AGCTPS and AGPTPS is also better than that of the conventional GCTPS and GPTPS. The glass transition temperature (Tg) was determined by differential scanning calorimetry (DSC). The glass transition temperature was increased with the increasing of aliphatic amidediol.Aliphatic amidediol was mixed with formamide and used as a mixed plasticizer for corn starch (AFCTPS) and potasto starch (AFPTPS) to prepare thermoplastic starch. The interaction between aliphatic amidediol/formamide and cornstarch was investigated using Fourier transform infrared (FT-IR). FT-IR proved that the mixture of aliphatic amidediol and formamide could form stable and strong hydrogen bonds with starch molecules. By scanning electron microscope (SEM) native starch granules were proved to transfer to a continuous phase. The mechanical properties and starch retrogradation behavior were also studied by tensile testing and X-ray diffraction (XRD), respectively. The glass transition temperature (Tg) was determined by differential scanning calorimetry (DSC). The water resistance of AFCTPS or AFPTPS was also better than that of the conventional FCTPS or FPTPS. Water represented an important role on TPS and the moisture content in starch affected significantly the properties of TPS. From our research, AFPTPS prepared with original water content of 10% possessed of good mechanical properties.The glass transition temperature (Tg) was decreased with the original water content decreasing.