| Three kinds of starch-based biodegradable polymer materials were synthesized and characterized in order to carry and control-release different medicaments.They were microporous starch,starch-encapsulation material and super absorbent resin by graft copolymerization of starch and acrylic acid.In order to produce microporous starch, two paths were studied as well as the effects ofα-amylase hydrolysis treatment and acid hydrolysis treatment on the formation of microporous starch from cornstarch. The morphology and structure of microporous starch was characterized by scanning electron microscopy (SEM),Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction. Physical and chemical properties of microporous starch were analyzed. Results showed that microporous structure had been formed on the surface of starch. Compared with native starch, microporous starch had lower retrogration, higher clarity, lower viscosity and better freeze-thaw stability. In the absorption experiment with water or oil, the ratio of absorption was higher than native starch. The optimum reaction conditions to prepare microporous byα-amylase were 0.5% mass ratio ofα-amylase to cornstarch, 40% concentration of starch paste, pH 5.8, polymerization at 50℃and 24h. The best craft parameters to produce microporous by acid were 6% mass ratio of acid to cornstarch, 40% concentration of starch paste, polymerization at 40℃and 12h.Starch-encapsulation material was synthesized by metamorphic starch and PVA as materials, BIS as cross linker and ClO2 as medicament. The structure and performance of starch-encapsulation material was characterized by Fourier Transform Infrared Spectroscopy (FTIR),differential scanning aclorimetry (DSC) and X-ray diffraction. The capacity of loading medicament and carried ratio were analyzed. Results showed that metamorphic starch and PVA were fully crosslinked by this method to form a close-grained encapsulation which packed the medicament inside. The capacity of loading medicament was 54.30mg ClO2 /g and carried ratio achieved 92.71%. The release speed of medicament was slow and the longest release time was 13h. The best reaction conditions were 0.2:1 mass ratio of PVA to metamorphic starch, 1750 polymerize degree of PVA, 1.5% mass ratio of cross linker to monomers, 5.9:1 mass ratio of solvent to monuments and 3.3:1 mass ratio of medicament to monomers.Synthesis of super absorbent resin was studied using graft copolymerization of cornstarch and acrylic acid by inverse suspension polymerization. The structure and morphology of super absorbent resin was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM). The absorbent ability of resin on water and ClO2 was analyzed. Results showed that graft copolymerization of cornstarch and acrylic acid was confirmed and the configuration and distribution of particle diameter of resin was well. In the absorption experiment with water and ClO2, the best absorbency of resin was 1666g/g on water and 119g/g on ClO2. The optimum preparation conditions were pasting starch at 90℃and 30min, 15.4% mass ratio of cornstarch to acrylic acid, 80% neutralization degree of acrylic acid, 1:3 mass ratio of W/O, 5.5% mass ratio of dispersant to monuments, 700r.min-1 agitation speed, 5m mol/L concentration of KPS, 0.087% mass ratio of cross linker, polymerization at 70℃and 3h. |
PDF Full Text Request