Study on Mechanism of Association between Hydroxy Ethyl Cellulose and Polyvinylpyrrolidone

The mechanism of association between hydroxy ethyl cellulose (HEC) and polyvinylpyrrolidone (PVP) has been studied by viscosity, UV, FTIR and DSC methods. The results indicated that the viscosity of PVP/HEC mixed systems displayed negative synergic effect, but the viscosity of HEC resistant to NaCl was enhanced in the presence of PVP. The reduced viscosity of the HEC solution was decreased when NaCl was being added and it became smaller with the concentration of NaCl increasing. The maximum absorb spectrum of the PVP/HEC mixed system had a red shift compared with their single systems. There appeared a new peak at 2370 cm-1in the FTIR spectrum for the complex system. Both UV and FTIR spectra showed that PVP/HEC complex was formed through the hydrogen bond. The investigation of DSC showed that the macromolecule chains were tightened due to the formation of the complexes.