| 摘要 |
The invention provides a cellulose semipermeable hollow fiber characterized by possessing an ultrafiltration coefficient KUFR in the range of about 2 to about 200 milliliters per hour per square meter per millimeter of mercury, a urea coefficient Kurea in the range of about 15 x 10<-3> to about 49 x 10<-3> centimeters per minute and a wet intrinsic tensile strength in the range of about 2 x 10<4> to about 11 x 10<4> grams per gram of cellulose polymer. The hollow fibre may be prepared by a process which comprises: (a) melt spinning a hollow cellulose ester fiber through a nozzle from a sulpholane-free melt spin composition comprising about 35 to about 80 weight percent cellulose ester and the balance at least one polyol having an average molecular weight between about 106 and about 902, provided that where a single polyol is used, its average molecular weight does not exceed about 600; (b) hydrolyzing said cellulose ester fiber substantially into a cellulose hollow fiber; (c) replasticizing said cellulose fiber while said fiber is still wet with a water soluble, essentially non-volatile plasticizer; and (d) drying said plasticized fiber. m |
