カルボキシメチルセルロース-水分散系の動的粘弾性

抄録

Weight average molecular weight (M_w) of sodium carboxymethylcellulose (NaCMC) has been determined by the light scattering in the solution of triethylenediamine cadmium hydroxide (cadoxene). The relation between M_w and the limiting viscosity number [η] in 0.1N NaCl aqueous solution has been obtained and it has been found that the Staudinger's relationship [η]=KM_w can be applied for these systems.
Dynamic viscoelastic properties of aqueous disperse systems of NaCMC have been measured by means of a cone-and-plate type rheometer. Using three series of NaCMC in the range of substitution (carboxymethyl residue/glucose unit) 0.5 to 1 with various degree of polymerization, the effects of the degree of substitution (DS), the degree of polymerization and the concentration upon rheological properties have been investigated. The influence of DS is marked in the long time-scale region. NaCMC of low DS remarkably shows a second plateau which is a characteristic property of the heterogeneous system. On the other hand, NaCMC of high DS behaves like homogeneous polymeric liquid.