Synthesis of poly(N-isopropylacrylamide)-b-poly(ε-caprolactone) and its inclusion compound of β-cyclodextrin

摘要

Well-defined amphiphilic poly(N-isopropylacrylamide)-b-poly(ε-caprolactone) (PNIPAM-b-PCL) block copolymers have been successfully prepared in two steps. PNIPAM-OH is firstly prepared by using 4,4'-azobis(4-cyano-1-pentanol) as bifunctional initiator, and then PNIPAM-b-PCL copolymer is synthesized via a ring-opening polymerization of CL using PNIPAM-OH as a macro-initiator in the presence of stannous octoate as a catalyst. The PNIPAM-b-PCL copolymers self-assemble to form spherical micelles of 50-130 nm in diameter, which can be modulated by the chain length of PCL block. The inclusion complexes are fabricated by treating PNIPAM-b-PCL with β-cyclodextrin and they are characterized by infrared and ~1H NMR spectroscopies, X-ray powder diffraction, thermogravimetric analysis, and differential scanning calorimetry.