Thermoresponsive and optically active polymer poly(N-acryloyl-L-valine N′-methylamide)(PAVMA-CCH) bearing amino acidamide moieties in the side chain was synthesized via reversible addition\|fragmentation chain transfer (RAFT) polymerization using 2\|dodecylsulfanylthiocarbonylsulfanyl-2-methyl\|propionic acid propargyl alcohol ester (DMPE) with alkyne group in the end as the chain transfer agent (CTA).Diblock copolymer MPEG-b-PAVMA was then prepared from “click” coupling reaction between PAVMA-CCH and polyethylene glycol monomethylether capped by azide group (MPEG115\|N3) in conjunction with CuSO4/ascorbate sodium as catalytic system.The chemical structures and molecular characters were evaluated by 1H-NMR and size exclusion chromatography (SEC)

respectively.The number of repeating unit for MPEG and PAVMA was 115 and 55

respectively

which was calculated from 1H-NMR analysis.The lower critical solution temperatures (LCSTs) for PAVMA and MPEG-b-PAVMA in water were 6.5℃ and 19.5℃

respectively

which were measured by transmittance tests on a UV-Vis spectrophotometer equipped with a temperature controller system.Specific optical rotation results showed that optical activity of the prepared PAVMA-C≡CH homopolymer and corresponding MPEG-b-PAVMA copolymer decreased comparing with that of monomer (AVMA) due to the variation of micro\|conformation during polymerization.Circular dichroism (CD) spectra for the aqueous solution of resulted polymers at 5℃ exhibit a weak Cotton effect peak at about 220 nm and a strong negative Cotton effect peak at around 197 nm

indicating random coil conformation for polymer chains in solution.