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 solution revealed that the pseudoplasticity flow behaviors took place at the PVALT composinamic 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.
수용성 고분자인 폴리비닐알코올 (poly(vinyl alcohol; PVA)과 폴리비닐알코올모노티올 (poly(vinyl alcohol) mono thiol; PVALT) 수용액의 표면장력에 대한 비교연구를 행하였다. 수용액에서의 표면장력은 PVA가 PVALT 보다도 켰으며, PVALTDML 검화도에 따른 표면장력은 검화도가 낮을수록 저하됨을 알 수 있었다. 아울러 PVALT 수용액의 점도와 동적 점탄성 특성을 회전점도계와 ARES rheometer로서 각각 측정하였다. PVALT (DP : 98) 수용액의 농도가 15.0 wt% 이상으로 증가함에 따라 유사소성 유변특성을 보였다.
PVALT(DP : 98) 수용액의 저장탄성률 (G`)은 손실탄성률 (G")보다 작았다. 이러한 결과들은 에멀젼에 대한 PVALTDML 보다 세밀한 응용연구에 도움이 될 수 있을 것으로 생각된다.
Keywords: surfae tension; rheological properties; poly(vinyl alcohol); poly(vinyl alcohol) momo thiol