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URN etd-0719107-212149 Statistics This thesis had been viewed 2128 times. Download 12 times. Author Rong-Huang Jhang Author's Email Address No Public. Department Materials Engineering Year 2006 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 157 Title Effects of Plasma Treatment and Acid Hydrolysis Modification on the Properties of Biodegradable Poly(vinyl alcohol)/Starch Blends Keyword starch acid hydrolysis plasma treatment biodegradable poly(vinyl alcohol) poly(vinyl alcohol) biodegradable plasma treatment acid hydrolysis starch Abstract In this study, Poly(vinyl alcohol) (PVA) and starch were used as main raw materials for products of biodegradable plastics. We used the single screw extruder to compound. Effects of plasma treatment and acid hydrolysis on the mechanical properties (maximum stress and strain), physical properties (Melt Flow Index, Water Contact angle) and the biodegrability by composting of composites were investigated. Besides, the correlation between the surface structure of sample and material properties was observed by the scanning electronic microscope (SEM).
In this investigation, the starch was degraded by various kinds of acid [such as acetic acid (AA), tartaric acid (TA) and citric acid (CA)] with various concentrations (0.25M, 0.5M, 1.0M and 1.5M). The melt flow index (MFI) of PVA/starch blend could be increased from 0.08g/10min to 4.54g/10min as the starch was degraded by 1.5M citric acid solution. The maximum strain of the compounded plastics that PVA blended with 1.0M CA acid hydrolysis starch was about 236%. The maximum stress of the sample that PVA blended with plasma (30W, 7min) treated starch was about 10MPa. From the SEM micrographs, it shows that the phase separation phenomenon between PVA and starch could be improved obviously by using high concentration (0.5M、1.0M、1.5M) acid solution to degrade the starch. The method of biodegradation measurement in this study was soil burial. The investigated samples were cut in (2×2×0.12 cm3) and then buried in the compost soil. After six weeks soil burial, the weight loss of acid hydrolytic samples were over 70 wt% ; the weight loss of plasma treatment samples were about 55 wt%.
Advisor Committee Chi-Yuan Huang - advisor
Files Date of Defense 2007-06-15 Date of Submission 2007-07-23