Effect of a Hydrophobic Branching Agent in Physically Cross‐Linked Hydrogels with Shape‐Memory and Self‐healing Abilities

Physically crosslinked hydrogels consisting of polyacrylamide (Aam) and polyoctadecylacrylate (C18A) blocks, leading to hydrophilic hydrophobic domains respectively, are prepared by micellar polymerization. A multifunctional monomer (divinylbenzene, DVB), is also employed create branched chains. The effect the polymer composition amount branching agent on material characteristics evaluated. melting enthalpies increase as n-octadecyl acrylate unit increases and, in a parallel fashion, an mechanical modulus G' hydrogel observed. Furthermore, G′ DVB concentration increases. Self-healing behavior demonstrated both visually rheological measurements. Finally, once heated above temperature (Tm), these can be deformed into different shapes that fixed cooling. Then, heating again Tm, original shape recovered thus indicating memory characteristics.