Intrinsic viscosities of cellulose derivatives

摘要: Intrinsic viscosities of cellulose acetates degrees substitution 2.86 and 3.00 trinitrate have been investigated as functions temperature, solvent, molecular weight. Large negative temperature coefficients (ca. −0.6% per degree) [η] appear to be characteristic cellulosic chains. These observed decreases in with are due increases chain flexibility, which reflected the ratio r/M. The rather large variations solvent shown also manifestations altered flexibilities brought about some manner, yet unexplained, by specific interaction. This behavior stands marked contrast that other polymers for r/M is independent varies only slightly effects on wholly attributable changes expansion (α3) action,