| The special effect produced by increase of amylose content of high amylose starch is widely noticed by resaerches of material science,and the change of its physical and chemical properties is of great signification to improve of the machine performance of starch based degradabal material and advance of the modification and plastisizing propertis of starch.In this paper,with arnylose starch as object,properties and aggregate-state struture were studied and charactered detailedly by morden observe and testing measure,and influence of change of amylose starch molecule's microstructure tO its macroscopical properties.Highly substitued acttylated amylose starch and high amylose starch thermalplastic cast film were prpared,of which stucture and properties were characterized.The main conclutions are as follow:1.Amylose starch granules' surface is not smooth,with all kinds of shapes.Maize and waxy starch granules' surface is smooth,with shape of polygon.Maltese Cross is clear and crossed in the center of granules.Granule size range of amylose starch is 3-30μm and its granules diameter of volume is smaller than that of maize starch.With the analysis of X-ray diffraction,amylose starch are attributed to type A of crystal type,which is different from maize starch.The value of crystal is about 20%,far lower than that of maize starch.Pasting tempreture is about 120℃,observably higher than that of maize starch.Almost all of the composition is carbohydrate,only very little protein and fat contained.Amylose starch is Of higher water-solubility and lower swell ability than maize starch and transparency is very small.Viscosity of starch paste increase with increase of tempreture at first,and then fall back, the peak value appears around 120℃.2.Amylose biodegradable themerplastic film was prepared with amylose starch,PVA, glcerol,glyoxal and so on.Optimal composition of reaction system and operating conditions were discussed.Properties of mechanics,rheology and degradable ability was tested too.The conclution showed that the film could redure certain pressure and pull and used as substitute of traditional wrappage.Could be easily and totally degrad in soil and keep good perfomance of mechanics in a period of time.3.Amylose starch acetates with high degree of substitution were synthesized by reaction of amylose starch and acetic acid/acetic anhydride catalyzed by MSA.The influences of reactants,reaction condition on DS of the high amylose starch acetates were discussed.The structure of the starch acetates has been characterized by infrared spectrum and X-ray diffraction.Best reaction system was determined:catalyzer 0.1mL,n(glucose):(acerbity)1:5.3, reaction tempreture 75℃,reaction time 3 hour.It was proved that amylose starch is easier to be acetated.Infrared spectra show that the hydroxyl groups of starch are really substituted since the stretching peak of hydroxyl decreases dramatically,the result of FTIR confirms that the difference between the structure of high amylose starch and the starch acetates increases with the introduction of acetyl.The result of X-ray diffraction shows that the crystal structure of high amylose starch a is damaged during substitution,the DS decreased frome about 20%to nearly 0.
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