Effect of the Degree of Quaternization and Molar Mass on the Cloud Point of Poly[2‐(dimethylamino)ethyl methacrylate] Aqueous Solutions: A Systematic Investigation

A systematic investigation to fine‐tune the cloud point of thermoresponsive poly[2‐(dimethylamino)ethyl methacrylate) (p(DMAEMA)) aqueous solutions in a broad temperature interval is reported. For this research, p(DMAEMA)s of different molar mass are quaternized at distinct degrees with methyl iodide to obtain an expanded library of poly[DMAEMA‐ co ‐poly[2‐(methacryloyloxy) ethyl] trimethylammonium iodide]s. Turbidity measurements show that depending on the molar mass of p(DMAEMA) and its degree of quaternization, the cloud point of the corresponding aqueous solutions can be adjusted within a rather broad temperature range from 23 to 70 °C. The cloud point and dynamics of the aggregation behavior of these polymers in the aqueous medium are also investigated by dynamic the light scattering. Furthermore, it is also found that the relationship between the molar mass and the cloud point of the respective aqueous solutions obeys an Arrhenius‐type model. image