Preparation of P(AM-co-MA) composite hydrogels by frontal polymerization and its performance study

Deep eutectic solvent (DES) was synthesized from choline chloride (ChCl) and acrylamide (AM), and P(AM-co-MA) hydrogels were prepared by adding different contents of maleic acid (MA) to DES by frontal polymerization. Fourier infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the hydrogels at the microscopic level, and the swelling properties, mechanical properties, self-healing properties and electrical properties of the copolymerized hydrogels were also investigated. The results showed that the equilibrium swelling of the hydrogels was significantly enhanced with the increase of pH due to the addition of MA. The hydrogel with the addition of MA has self-healing properties that pure PAM does not have. In terms of electrical conductivity, the increase of MA makes the internal structure of the hydrogel more loose, which is conducive to the passage of free ions. And there is a significant effect of different temperatures and different crosslinker contents on the electrical conductivity. In summary, we prepared a P(AM-co-MA) hydrogel that can produce significant property changes in response to changes in the external environment, which is expected to expand the application of hydrogels in flexible electronic materials.