- 作者: 邱文英; 陳劉旺; 李世煌
- 作者服務機構: Department of Chemistry Engineering, National Taiwan University, Taipei, Taiwan, R.O.C.
- 中文摘要:
A series of polyurethanes based on hydroxyl-terminated polybutadiene(HTPBD) and cured with Bis-(-hydroxy ethyl)-terephthalate (BHET) have been synthesized. Mechanical, microscopic and kinetic studies were carried out to elucidate the structure-property relationships from the view point of phase separation. We studied the effects of the polymerization method, varying the hard to soft segment ratio and changing the hard-segment domain structure on the properties of the subject materials.
Dynamic mechanical responses showed that the Tg of the soft-segment at -60.degree.C was independent of the hard-segment content, which indicates that the copolymers were well phase separated. A higher hard-segment content brought about a slight increase in the modulus, a moderate increase in the tensile strength and a decrease in the ultimate elongation.
The size of the hard-segment domain, as estimated from electron micrographs, ranged from 60.ANG. To 100.ANG.. It was observed that a higher content of hard-segments causes an increase in the hard-segment domain size. In addition , a general survey of the reaction rate indicateed that BHET is less reactive with diphenyl methyl diisocyanate (MDI) than with HTPBD. - 英文摘要: --
- 中文關鍵字: Bis-(2-hydroxy ethyl)-terephthalate chain extender; dynamic mechanical property; EMP.
- 英文關鍵字: Bis-(2-hydroxy ethyl)-terephthalate chain extender; dynamic mechanical property; EMP.