A study on solid structure of regenerated cellulose fibers related with fibrillation

It is well known that the Cupro(R), Polynosic and organic solvent span rayons, such as Tencel(R), and Lyocel(R) fibers are easy to fibrillate. The Rayon fiber is difficult to fibrillate. We developed fibrillation-resistant Cupro(CUPRO2) by means of a new spinning method. In this study, we attempted to compare the solid structures of CUPRO2, Cupro(CUPRO1), Rayon(RAYON) and Lyocel(LYOCEL) in order to discover the factors governing the fibrillation. To this end, WAXD, Dynamic viscoelastic analysis, and CP/MASS (CNMR)-C-13 analysis were carried out. The measured fibrillation resistance grade was as follows: RAYON(95) > CUPRO2(75) > CUPRO1(40) > LYOCEL(10). Crystallinity index, degree of crystallite orientation, and apparent crystallite size estimated for the (<1(1)over bar>0) plane decreased with increasing fibrillation resistance grade. The peak temperatures of alpha 1 and alpha 2 dispersion (Tmax alpha 1, Tmax alpha 2) measured from the mechanical loss tangent-temperature curve increased in order of the fibrillation resistance grade, that is to say, the inter- and intra-molecular hydrogen bonding seemed to increase with increasing fibrillation resistance grade. It may be concluded that the fibrillation characteristic is greatly influenced by the degree and strength of inter- and intra-molecular hydrogen bonding in the amorphous region at the surface of the microfibril.