| Summary: | 碩士 === 國立勤益科技大學 === 化工與材料工程系 === 101 === This thesis investigates a fixed isocyanate monomer (4,4 '-MDI), and then use two types of polyol (a polyether polyol (PTMEG) and three kinds of polyester polyol (PBS, PCL, PBA)), and four kinds of chain extender (1,4 - butanediol (1,4-BG), 1,4 - butanediol + neopentyl glycol (NPG),1,4-butanediol+trimethylolpropane(TMP),hydroquinone(β-hydrocarbon-ethyl) ether (HQEE) to synthetic thermoplastic polyurethane material. After hardening the thermoplastic polyurethane material is then with acetone、ethyl acetate、toluene、heptane and glycerol were placed in five different solvent 1、3、7 days, to observe and investigate the mechanical properties and resistance to chemical degradation.
The results of this study showed that the polyester-urethane than polyether-urethane has better chemical resistance properties under the same hardness. This is because the polyester base thermoplastic polyurethane material having an ester group with more polarity、higher crystallinity and large intermolecular cohesive energy. The main chain of polyurethane material containing PTMEG with chain extender of 1,4-BG+NPG in the mechanical properties and solvent resistance is the worst of all the TPU, which may be due to NPG (neopentyl glycol) having a side chain methyl structure makes mechanical properties decreased、intermolecular cohesive energy is small as well as the crystallinity becomes smaller, but it has a better transparency.
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