Influence of different solvents on rheological behavior of polyvinyl alcohol solution system
The rheological behavior of polyvinyl alcohol(PVA)aqueous solution and PVA/dimethyl sulfoxide(DMSO)solu-tion systems with different PVA content was tested with water and DMSO as solvents using a rotary rheometer.The effects of PVA content,temperature and solvents on the rheological behavior of PVA solution systems with high degree of polymerization and al-coholysis were studied.The results showed that the apparent viscosity(ηa)of PVA aqueous solution and PVA/DMSO solution sharply decreased with the increase of shear rate,which exhibited pseudoplastic fluid behavior;the ηa of PVA aqueous solution and PVA/DMSO solution sharply increased,the storage modulus(G')and loss modulus(G″)also increased,and the viscoelas-tic behavior was enhanced with the increase of PVA content;compared with PVA aqueous solution system,PVA had a higher solubility and a larger molecular fluid dynamics volume in DMSO;PVA/DMSO solution system had ηa,G' and G″ higher than PVA aqueous solution system at the same PVA content;and the temperature elevation can enhance the PVA segment mobility,offsetting some of the shear effects on the rheological behavior of PVA solution systems.