Study on the Optimum Operating Conditions and Biodegradable Characteristics of PHBV/ Tapioca-starch Blended with Glycerol/TEC/Xylitol

Autor: Chia-Yang Wu, 吳佳洋
Rok vydání: 2013
Druh dokumentu: 學位論文 ; thesis
Popis: 101
Response surface methodology was used to analyze the effects of PHBV/tapioca starch ratio, xylitol and barrel temperature of extruder on the objective attributes (max. loading, max. displacement, water absorption, glass transition temperature, melting temperature and thermal degradation temperature) of a tapioca starch/PHBV blended composite. A Box-Behnken design was used to develop models for the objective responses. The experiments were performed at screw speed 45 rpm and feeding speed 20 g/min. Tapioca starch, PHBV and plasticizer of the raw material formulation of total weight was set for 1 kg. The levels of PHBV/tapioca starch ratio were 7:3, 6:4, 5:5, the levels of xylitol were 45 g, 60 g, 75 g and the levels of barrel temperature of extruder were 140℃, 155℃, 170℃. Individual contour plots of the different responses were overlaid. Regions meeting 243.75 N, 2.56 mm, 24.64% were identified at 37.40%, 59.60 g and 154.82℃. The results indicated that the glass transition temperature (Tg) of extruded pellets ranged from -8.81~-12.54℃, the melting temperature (Tm) ranged from 154.48~159.56℃and the thermal degradation temperatures (Td) ranged from 290.12~296.65℃. The biodegradability of the extruded pellets were tested according to the CNS14432 standard. The result indicated that the biodegradability of the extruded pellets reached 70.4% after 34 days and 75.5% after 45 days, respectively. Moreover, by using the enzymes analysis method, the weight loss reached 70.2% after 480 min. Therefore, it could be concluded that the plastic pellets developed in this study consist of biodegradable properties, which can help to solve environmental problems. These pellets are suitable for industrial application.
Databáze: Networked Digital Library of Theses & Dissertations
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