Surface tension and rheological properties of poly(vinyl alcohol) mono thiol V

Comparative studies have been made on the surface tension of aqueous solution of poly(vinyl alcohol)(PVA) and poly(vinyl alcohol) mono thiol (PVALT). The surface tension of the PVA in aqueous solution was larger than that of the PVALT. The surface tension of the PVALT decreased with decreasing the degree of saponification of the PVALT. In addition, the viscosities and dynamic mechanical properties of aqueous solution of PVALT were measured by using a rotational type viscometer and a ARES rheometer, respectively. The PVALT (DP:98) had a near non-Newtonian flow behavior at a certain shear rate range. However, by increasing number average degree of polymerization(DP), the aqueous solution of PVALT showed a typical pseudoplasticity flow behavior. The PVALT(DP:98) aqueous solution revealed that the pseudoplasticity flow behaviors took place at the PVALT composition of 15.0 wt%. Dynamic storage modulus(G') of PVALT (DP:98) was smaller than dynamic loss modulus(G ") at the 15.0 wt% aqueous solution state. These results are expected to be useful in the study of emulsion properties in detail.