Rapid Responsive Behaviors of the Dual Stimuli-Sensitive Poly(DEA-co-DMAEMA) Hydrogel via Comb-Type Grafted Polymeriziation

The dual-sensitive, comb-type grafted hydrogels were synthesized by grafting polymeric chains with freely mobile ends, which were composed of both N,N-diethylacrylamide (DEA) and (2-dimethylamino) ethyl methacrylate (DMAEMA), onto the backbone of crosslinked poly(DEA-co-DMAEMA) networks. The structure of the poly(DEA-co-DMAEMA) macromonomer was characterized by Nuclear Magnetic Resonance (H-1 NMR) and Fourier transform infrared spectroscopy (FTIR). The effects of the feed components, temperature, and pH on the swelling behavior of the hydrogels were studied. With the increase of the poly(DEA-co-DMAEMA) macromonomer content, the thermo- and pH-sensitivity of the hydrogels improved. The G-PDD hydrogels exhibited improved thermo- and pH-sensitive characteristics, such as faster deswelling and reswelling rates and great oscillating deswelling/swelling behavior, and the level of improvement depended on the poly(DEA-co-DMAEMA) macromonomer content. The proposed dual thermo- and pH-sensitive, comb-type grafted poly(DEA-co-DMAEMA) hydrogel has various potential applications.