Abstract
Well-defined stimulus-responsive polymer gels were prepared from poly(2-vinyl-4,4-dimethylazlatone) (PVDMA) via one-pot post-polymerization modification. VDMA homo-polymers were reacted with diamine crosslinking agents and functional 1 or 2 amines to form polymer gels that swelled in organic solvents and, in many cases, aqueous solu-tions. A series of functional amine reagents, including N,N-dimethylethylenediamine (DMEDA), N,N-diethylethylenediamine (DEEDA), morpholine, 3-morpholinopropylamine (MPPA) and tetrahydrofurfurylamine (THFA), were chosen as functional amines to produce polymer gels containing environmentally sensitive species. 13C solid-state NMR and FTIR spectroscopic measurements confirmed complete conversion of the reactive scaffolds. pH-dependent swelling behavior at ambient temperature was observed in DMEDA-, DEE-DA- and MPPA-modified hydrogels. Kinetic studies showed the swelling behaviors of DME-DA-modified hydrogels were regulated by cross-linker type and concentration in acidic water (pH = 4) at ambient temperature. The swelling ratio of hydrogels modified by DEE-DA, MPPA and THFA also depended strongly on temperature, indicating successful synthe-sis of thermoresponsive gels. Furthermore, the concentration of added sodium sulfate played a significant role with respect to the swelling properties of MPPA-modified hydro-gels. These smart materials may be of interest in the biomedical field as well as in other applications.