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

Abstract

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.

Magnetic Nanoparticles Coated with a Thermosensitive Polymer with Hyperthermia Properties

“…When the temperature is raised above the LCST, the entropy term (hydrophobic interactions) dominates leading to polymer precipitation. It has been demonstrated [ 34 ] that the quaternization of this polymer increases its hydrophilic character, and therefore the LCST is shifted toward higher temperatures as more energy is required in these systems to break the more stable interactions between the new added cationic species in the polymer and water molecules [ 35 ]. Hence, as shown in Figure 9 , when temperature is increased, the average size of the polymer envelope increases by aggregation of already existing magnetite/polymer composites, as such aggregation is favored by the increased hydrophobicity of the PDMAEMA envelope.…”

Effects of Hydrophobic Modifications on the Solution Self-Assembly of P(DMAEMA-co-QDMAEMA)-b-POEGMA Random Diblock Copolymers

“…Moreover, the presence of cationic groups allows the utilization of the present copolymers in gene delivery applications and increases the antifouling ability of the copolymers [ 49 ]. By modifying only part of the total amount of amino groups, responsiveness of the diblocks to pH and temperature variations is expected to be altered but not to be completely absent [ 46 , 60 ]. The addition of long alkyl chains of different lengths is another interesting characteristic that is worth investigating as they impart amphiphilic character to the random diblock and as a result, they affect the self-assembly properties [ 44 ].…”

Exogenous Application of Polycationic Nanobactericide on Tomato Plants Reduces the Candidatus Liberibacter Solanacearum Infection

“…The quaternization of P(DMAEMA- stat- BMA) copolymer was carried out using methyl iodide following a procedure reported elsewhere [ 30 ], which was modified to achieve a higher degree of quaternization and yielded a poly((2-[methacryloyloxy]ethyl)trimethylammonium iodide- stat -BMA) (P(METAI- stat -BMA)) copolymer denoted as Q-COP.…”