Abstract
The effect of ultrafiltration (UF) operation on the stability of a sizing agent based on starch has been studied. Hydroxypropyl starch (HPS) has been used as a water soluble modified starch. The investigation was carried out in two categories:
a) effect of UF time (the concentration of the solution was kept constant by recirculating the permeate), and b) raising the concentration by discharging the permeate.
The changes in the HPS solution properties were assessed by investigating the rheological properties (apparent viscosity as a function of filtration time, temperature and activation energy of flow) and molecular properties (Infra-Red spectroscopy (IR), number of average molecular weight (M(n)) and molecular weight distribution). The investigation was carried out on HPS solutions before, after and during the ultrafiltration process. The results indicated that some degradation takes place during UF process.