General introduction -- Control of Thermoresponsive Properties of Urea End-Functionalized Poly(N-isopropylacrylamide) Based on the Hydrogen Bond Assisted Self-Assembly in Water -- Precise Synthesis of Poly(N,N-Dimethylacrylamide) by Group Transfer Polymerization Using a Strong Brønsted Acid and an Amino Silyl Enolate -- Facile Synthesis of Thermoresponsive Block Copolymers Bearing Poly(N,N-diethylacrylamide) Segment through Group Transfer Polymerization -- Conclusions.