Splitting tendency of cellulosic fibers. Part 2: Effects of fiber swelling in alkali solutions

摘要

The splitting tendency of lyocel1 fiber in aqueous alkali solutions like KOH, NaOH, LiOH and TMAH was investigated. Up to 5 M concentration of alkali solutions, cation type is important on splitting of lyocell. Above 5 M concentration, cation type is no more relevant to splitting of lyocell. At I M of alkali solutions, alkali retention value (ARV) and split number increase in the order of KOH < LiOH < NaOH < TMAH. It was proposed that lyocell is swollen homogeneously inside fiber above 5 M alkali concentration, so that when force is applied on fiber, no split occurs in lyocell fiber since there isn't enough internal stress inside of the fiber. Different concentrations of each type of alkali result in the same ARV for the fiber, but their alkali distribution inside fiber is the decisive point for splitting of lyocell fiber, so that for each alkali type different split numbers are observed. Depending on alkali concentration and alkali type, maximum splitting of a fiber into 15-20 fibrils could be observed.