Phase behaviors of poly(sulfobetaine methacrylate) in various concentrations of NaCl aqueous solutions at critical transparent state

ABSTRACT

The phase behaviors of poly(sulfobetaine methacrylate) (polySBMA) in various concentrations of NaCl aqueous solutions at critical transparent state were investigated utilizing UV–vis analytical techniques. The effects of the molecular weight and temperature on the phase behavior of polySBMA at the critical transparent state were discussed in detail depending on the relationship between the concentration of NaCl, the concentration of critical polySBMA structural unit, and the molar ratio (R_C) of NaCl to the critical polySBMA structural unit. The results demonstrate that there exists a positive polymer concentration effect on the transparency. A relationship between the molecular weight, the concentration of NaCl, and the concentration of critical polySBMA structural unit was obtained, which provides a new method for measurement of the molecular weight of polySBMA. The polymer concentration effect for the polySBMA solutions at lower temperature was remarkable, which was similar to that for the polySBMA solutions with higher molecular weight.

GRAPHICAL ABSTRACT

KEYWORDS:

• Critical transparent state
• molecular weight
• phase behavior
• polymer concentration effect
• PolySBMA