Phase transition in polymer hydrogels investigated by swelling, DSC, FTIR and NMR

• DOI: 10.1007/s10973-024-13380-5
• Publication Date: 2024-07-10T06:02:31Z
• Authors: Ivan Krakovský; Lenka Hanyková; Julie Štastná
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract The swelling and thermal behavior of single (SN) double network (DN) hydrogels containing polyacrylamide (PAAm) temperature sensitive poly( N , -diethylacrylamide) (PNNDEAAm) were investigated by gravimetry differential scanning calorimetry (DSC). Changes the hydration carbonyl groups mobility polymer chains in with studied Fourier-transformed infrared proton nuclear magnetic resonance ( 1 H NMR) spectroscopy. enthalpy dissociation hydrophobic interaction, minimum maximum numbers water molecules per monomer unit PNNDEAAm SN hydrogel involved determined DSC. volume phase transition accompanied expulsion/uptake heat absorption/release heating/cooling was exhibited all DN PNNDEAAm. In these hydrogels, above temperature, population hydrated carbonyls is enriched free ones same way as aqueous solution linear strongly reduced. Presence PAAm does not influence but reduces transition, promotes higher degrees carbonyls, increases mixed temperature.