| Summary: | 碩士 === 大同大學 === 材料工程學系(所) === 103 === The composites in this study were mancefactured by a variety of different ratios of sebacic acids, glycerols and modified starch with different temperatures.
Then, their mechanical properties, water contact angles, FTIR, thermal analysis, Life cycle carbon footprint and biodegradable test were investigated.
Two kinds of processes were studied in this work. They were the process with unheated glycerols and the process with heated glycerols and the process with heated glycerols. In the process with unheated glycerols, the sebacic acids(SA) and glycerol were mixed with starch. Finally, the mixture was blended by a single-screw extruder to prepare a biodegradable material. During the extrusion process, the starch will be modified. In FTIR spectrum of the composite, there are ester based characteristic peaks at 1730 cm-1 C=O. It proved an esterification reaction occurred and the starch was modified. It will improve the hydrophobic effect of the composite and was illustrated by the measurement of the contact angles that the original ST water contact angle of 43.0 degrees increased to 59 degrees.
In the second kinds of process, the esterification reaction carried out by heating the mixture of sebacic acids(SA) and dimethyl saulfoxide(DMSO) as well as the glycerol, then mixed with the starch and biended by a single-crew extruder. The FTIR spectrum also showed the ester based characteristic peaks. The DMSO and heating can improves the esterification, where SA is 3g and DMOS is 0.05g. The break elongation increased from the original 160% to 190% and the stress reduced from the original 5.2MPa to 4.3MPa, In addition water contact angle increased from 53 degrees to 69 degrees, because of improvement of hydrophobic by esterification of starch.
|
|---|
