| The composite which used by maleic anhydride modified potato starch and PVA has enough mechanical properties also can completely biodegradable with no damage to environment.This article carried out thorough research in selection and control of potato starch's acylation process, condition optimization of acylation process and how to improve strach-modified material's hydrophobicity & mechanical property.1. In the solvent of polyethylene glycol, maleic anhydride modified starch's crystallinity significantly decreased..When maleic anhydride:strach<0.5, maleic anhydride can commendably reduce strah's crystallinity,decrease hydroxy quantity,esterify more hydroxy,also decreased the hydrogen bonding among chains.2. The effect of solvent,temperature,PH,dosage of maleic anhydride and action time on DS and crystallinity were investigated. The degree of crystallinity was characterized use DSC, the results show that, in polyethylene glycol, 50℃, PH=8.0～8.5, maleic anhydride:strach=0.5, action time=3.5h, the DS is reached the maxmum(1.88), the crystallinity decreased significantly.3. The influence of additive ratio and PVA dosage on PVA/modified starch film's capability and application property was investigated. Showed that, when modified starch: PVA = 10:3:1,dosage of KH550 and glass fiber is 3% and 7%, it's mechanical properties reached the sevice index of film. The tensile strength and breaking elongation are respectively 25.03MPa and 25.6%.4. Through degradation property test, the film had 26% weighlessness after 40d and 70% weighlessness after 68d when modified starch was most degraded. |
PDF Full Text Request