Investigation of the interpolymer complex between hydroxypropyl cellulose and maleic acid-styrene copolymer, 1 - Dilute solutions studies

The hydrogen bonding-interpolymer association of hydroxypropyl cellulose (HPC) with maleic acid-styrene (MAc-S) copolymer has been investigated in dilute aqueous solution by viscometry, turbidimetry and potentiometry. At a mixing ratio between MAc-S and HPC of 10:90, the solution exhibits a phase separation upon heating, while for other mixing ratio no phase separation could be detected. The stability of the interpolymer complex (IPC) increases as the temperature rises. The stoichiometry of the IPC, in mole units, was estimated as being MAc-S:HPC = 5:2. The thermodynamic functions (enthalpy and entropy) of the complexation process have been determined.