STUDIES ON CRYSTAL HARD DOMAIN OF SEGMENTED POLYETHER URETHANES
硬链段结晶性嵌段聚醚聚氨酯的合成研究

We have investigated the synthetic methods of segmented polyether polyurethane (PEU) through polytetramethylene glycol-4, 4'-diphenyhnethane diisocyanate (PTMG-MDI) prepolymer with ethylene diamine (ED) as extender and observed that different methods of adding reagents in the two-stops solution polymerization -will result in the formation of two-phase components block copolymers with different morphology and somewhat different physical properties. Method A, adding PTMG solution to MDI then adding extender to the resulted prepolymer solution will always show better phase separation and give cystal herd domain in the size of 50--80A, while method Busual-ly give amorphous hard domain with much larger size of 1000--2000 A.