Abstract
The present work was undertaken to achieve two aims
1) the recoverability of carboxy methyl starch (CMS) from the diluted solutions (desizing solutions) by using the ultra-filtration (UF) technique,
2) the extent of changes in the physical and mechanical properties of CMS as sizing agent after the UF recovery.
In order to investigate the effect of UF recovery on CMS properties, the diluted CMS solution was subjected to two UF cycles during the recovery, and the end product of each cycle was intensively examined. The investigations are included: the characteristic UF factors (rejection "R", and flux of permeate "V"), viscosity, average molecular weights, molecular weight distribution (MWD), and the mechanical properties (adhesive force, weaving properties as abrasion percent AG "dust and fluff", and clinging factor TK). The obtained results showed that:
1. The efficiency of the UF recovery of CMS is higher in the second than the first UF cycle.
2. The viscosity of CMS is:
a) lower after than before the first UF cycle,
b) higher after than before the second UF cycle.
3. The average molecular weight determinations are indicated the occurrence of degradation in CMS molecules.
4. The MWD are shifted towards unity after the UF recovery.
5. The changes in the mechanical properties of CMS after the UF recovery are:
a) Adhesion force decreased.
b) Abrasion % (dust and fluff) decreased.
c) Clinging factor TK increased.