| 摘要 |
PURPOSE:To provide the above porous membrane composed of uniform microfibrils interlocked with each other in the form of net, having high intramolecular hydrogen bond property, low influence upon human body and excellent mechanical strength and useful as ultrafiltration membrane, blood dialysis membrane, etc. CONSTITUTION:The objective porous membrane has a cellulose I crystal system having an intramolecular hydrogen bond property Hb of >=80% (estimated from a solid 13C-NMR peak originated form C4 carbon of glucopyranose ring constituting a cellulose skeleton) and a polymerization degree of >=800. The membrane is constructed of cellulose microfibrils having diameter of 1.5-10nm and interlocked with each other in the form of net. The average pore diameter of the membrane is <=3,000nm (measured by water flow-rate method) and the porosity Pr is 50-93%. Preferably, the dynamic modulus of the membrane is >=7.8X10<9> (100-Pr)<-1>dyne/cm<2> at 30 deg.C and a measuring frequency of 110Hz and the peak temperature Tmax of the mechanical loss tangent tandelta is >=210 deg.C.
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