Preparation of Poly (N-Isopropylacrylamide) -Poly (2-Ethyl-2-Oxazoline) and Their Self-Assembly Properties with Dicarboxylic Acid

This study reports the synthesis of copolymers that contain thermally responsive polymers, namely poly(N-isopropylacrylamide) (PNIPAM) and poly(2-ethyl-2-oxazoline) (PEOX), as well as biodegradable side groups that are water-soluble and capable of hydrogen bonding. The assay aims to produce heat-responsive PNIPAM and PEOX polymers with di-carboxylic acid (DCA) controlled structuring of the resulting pH-sensitive nano-structured polymers. These will be used as a template in the synthesis of inorganic materials. The study demonstrated the impact of pH, salt concentration, and temperature on the polymer/DCA. This fragment describes the functional groups of the thermosensitive polymers PNIPAM and PEOX. These polymers have carboxylic acid functional groups at both ends, are water soluble, and are capable of hydrogen bonding. The structure of these polymers can be recognized with small molecules of DCA in an aqueous solution at different pH, salt concentrations, and temperatures with H-bonds. Additionally, these polymers can be used as templates to synthesize hollow silica polymers. The synthesized monomers and polymers were structurally characterized using Fourier transform infrared spectrophotometer (FT-IR). The resulting structured polymers were identified by scanning electron microscopy and atomic force microscopy (SEM, AFM). UV-VIS spectrophotometer and Differential Scanning Calorimetry (DSC) were used to determine the Lower Critical Solution temperature of the polymers.