Abstract
An improvement of moisture sorption (MS) ability of polyurethane (PU) was attempted by blending cellulose (Cell). PU-Cell blend was prepared from PU-cellulose diacetate (CA) blend by saponification. CA was apparently miscible with PU in a wide range of blend ratio on the optically microscopic observations. However, the incompatible interaction between them in less than 70 % CA content was suggested by Db from the viscosity measurement. Saponified CA formed cellulose II structure in PU at above 30 % CA content. Essentially, CA was, therefore, immiscible with PU. The MS of PU fibers blended with 5 % of CA was dramatically enhanced after 1 % NaOH treatment. In the case of films, the MS was increased by the increase in CA content without saponification. By saponification, the MS ability was further improved.
