| 초록 |
Thermoresponsive polymers that are pH tunable were successfully synthesized by a combination of atom transfer radical polymerization (ATRP) and Cu(I)-catalyzed 1,3-dipolar cycloaddition of azide and alkynes (click chemistry). ATRP was employed to synthesize poly(2-hydroxyethyl methacrylate) (PHEMA), followed by introduction of alkyne groups using pentynoic acid, leading to HEMA-alkyne. 2-Azidoethylamine, 2-azido-N,N-dimethylethylamine, and 2-azido-N,N-diethylethylamine were added to the HEMA-alkyne backbone via click chemistry. Results showed that the lower critical solution temperature (LCST) could be dramatically affected by solution pH. To give additional evidence for pH-responsive thermal transition, in situ temperature-dependent 1H-NMR measurements in deuterated water (0.01 wt%) were conducted. The LCST values measured by in situ 1H-NMR correlated well with those determined by turbidimetry. |
