Application And Preparation Of Hydrophobic Starch Microspheres

Starch has been considered as an alternative biomaterial because of its biodegradability, renewable and low cost. However, the application of pure starch-based material is still limited due to its water sensitivity and brittle. In this thesis, hydrophobic starch octanoate and starch mixed ester has been prepared successfully. Starch octanoate of emulsifying properties has been researched. Starch based nanoparticles has been synthesized by mixed ester, and poly((?)-caprolactone) (PCL) blending, get biodegradable composites. To explore energy-storage materials of the nature higher plants into function of the new material possibilities.Starch octanoate (St-C8) was prepared by corn starch and octanoyl chloride in aqueous slurry. Using acid-base titration methods determined the degree of substitution of product. The structure of St-C8 was identified by infrared spectrum. The results of X-ray diffraction showed that reaction of corn starch with octanoyl chloride caused change in the crystalline structure. Starch octanoate diffraction peak disappeared and appeared more wide dispersion peak. Starch particles lost crystal structure, amorphous layer became thicker, at last the particle crystalline structure was destroyed. TG analysis showed that thermal stability of starch octanoate got higher with the DS increasing. Compared to native starch, the hydrophobic performance of esters was greatly increased. With the DS increasing, contact angles were gradually increased.Starch octanoate was corn starch with fatty acids generated esterification product. It can be used as emulsifier because this kind of starch ester molecules contained strong hydrophobic alkyl groups and strong polarity of hydroxyl groups. This paper studied that St-C8 was used as the emulsifier of soybean oil and water system. The effect of DS, emulsifier concentration and the proportion of oil phase and water phase (Vo/w) on the emulsibility and emulsified stability of emulsion were also investigated in detail. The result indicated that St-C8 exhibited the best emulsibility and emulsified stability when the DS and concentration are 0.37 and 7%wt, respectively. Furthermore, the emulsion exhibited the best emulsibility and emulsified stability when the VO/W is 4/6 and 2/8, respectively.An efficient procedure was developed for the preparation of uniform nanospheres by nanoprecipitation. The size of the nanospheres can be tuned by adjusting the concentration, the proportions of the water and organic phases. Use of mixed molten, The starch nanospheres/ployeaprolaetone blend is prepared. It is entirely degradation material. The research shows that starch nanospheres is increased with a mixed ester of concentration and the proportions of the water and organic phases of advance. Starch nanospheres of the content affect the mechanical properties and hydrophobilities of starch nanospheres.