A multi-stimuli-responsive poly(NIPA-co-HEMA-co-NVP) with spironaphthoxazine hydrogel (poly(NIPA-co-HEMA-co-NVP-co-SPO)) was prepared by radical polymerization. The structure of this hydrogel was characterized by FTIR, 13C NMR spectra, and SEM. Equilibrium swelling measurement and UV-vis spectra were applied into evaluating thermo-responsive, pH-responsive and light-responsive properties. These results exhibited poly(NIPA-co-HEMA-co-NVP-co-SPO) hydrogel with excellent stimuli-responsive characteristics including thermal, pH, and light stimulation. Meanwhile, the obvious change for internal microstructure of hydrogel was observed by SEM after UV irradiation and in acidic condition. In addition, the poly(NIPA-co-HEMA-co-NVP-co-SPO) hydrogel with good mechanical property can be utilized in erasable and rewritable photoimaging based on the photochromic effect, which makes it a potential application in rewritable optical memory media or imaging processes.

A new polymer was prepared from γ-poly (glutamic acid) (γ-PGA) and glycol diglycidyl ether. IR verified perfectibility of the reaction. DSC and SEM indicated the higher thermal stability and Dk respectively. Optical transmittance is 98%.