Synthesis of a Novel pH-and Salt-Responsive Super Absorbent Hydrogel based on Collagen-g-poly(AA-co-IA)

摘要

In this work, a novel family of pH-responsive polymeric hydrogel based on collagen was prepared. Acrylic monomers, acrylic acid (AA) and itaconic acid (IA) were simultaneously graft copolymerized onto collagen backbones by a free radical polymerization technique using ammonium persulfate (APS) as initiator and methylene bisacrylamide (MBA) as a crosslinker. A mechanism for the superabsorbent hydrogel formation was also suggested. Hydrogel formation was confirmed by FTIR spectroscopy. Results from scanning electron microscopy (SEM) observation also showed a porous structure with smooth surface morphology of the hydrogel. The swelling capacity of hydrogels was also measured in various salt solutions (LiCl, NaCl, KCl, CaCl2 and AICl3). Due to high swelling ability in salt solutions, the hydrogel may be referred as "anti-salt superabsorbent" polymers. Furthermore, the water absorbency of hydrogels was measured in solutions with pH ranged 1 to 13. The collagen-based hydrogel exhibited a pH-responsiveness character so that a swelling-deswelling pulsatile behavior was recorded at pHs 2 and 8.