| 摘要 |
<p>Polytetramethylene ether glycol having a narrow molecular weight distribution of about 1.30 to 1.70 is made by a process comprising (1) partially depolymerizing polytetramethylene ether glycol to tetrahydrofuran in the presence of a cross-linked acid form ion exchange resin at a temperature of about 120 to 150.degree.C. while removing a major portion of the tetrahydrofuran produced, (2) cooling to about 70 to 90.degree.C., (3) filtering to remove the resin from the polytetramethylene ether glycol, and (4) drying under reduced pressure. The narrow molecular weight polytetramethylene ether glycol made thereby has a number average molecular weight of about 1600-3200 and a viscosity of about 4-20 poise at 40.degree.C. It is useful in making polyurethane fibers and films.</p> |
