Viscoelastic Properties of Three-dimensional Cellulose Fiber Networks
The storage modulus, G’, and the loss modulus, G, of the fiber networks were independent of the angular frequency at any fiber concentrations. It is a typical feature for a network structure in which fibers connect with each other over the whole systems. The moduli G’ and G increased with fiber concentration, c. The relationship between G’ and c can be expressed by G’=kcα. The exponent, α, was 9/4 for three-dimensional random networks. In contrast, the exponent was 3 for wet pulp fiber webs, which have laminated network structures, and 5 for a microbial cellulose pellicle, having another laminated structure. This indicates that the exponent itself reflects the intrinsic properties of the fiber network structures. On the other hand, the front factor, k, of the power relation varied with the fiber axial ratio and the fiber flexibility. That is, the factor reflects the individual fiber characteristics. The concentration dependence of the moduli can be discussed in detail from the viewpoint of scalar transport of momentum using a two-dimensional lattice model. When the stress transmittance occurs with no loss and the fiber length is far larger than the fiber diameter, the exponent of five is predicted in the model. This model also shows the elastic modulus is proportional to the concentration and to the square of the axial ratio of the fiber, which corresponds well with the experimental results.
Daisuke TATSUMI
Faculty of Agriculture, Kyushu University, Japan
国际会议
南京
英文
665-669
2010-10-22（万方平台首次上网日期，不代表论文的发表时间）