Synthesis and characterization of PCL-b-PEO-b-PCL-based nanostructured and porous hydrogels.
Hydrogels with nanoscale structure were synthesized using amphiphilic poly(epsilon-caprolactone)-poly(ethylene oxide)-poly(epsilon-caprolactone) (PCL-b-PEO-b-PCL) triblock copolymers. Small-angle X-ray scattering (SAXS) studies show that the block copolymers form 30-40 nm structures in aqueous solution and that these patterns are retained, with some increase in length scale, following electron beam cross-linking. Lamellar nanostructures were observed by SAXS and atomic force microscopy (AFM), with SAXS indicating cylindrical structure as the block lengths become more different in length. It is demonstrated through Fourier transform infrared spectroscopy (FTIR), mass loss, and differential scanning calorimetry (DSC) that the PCL can be completely removed by hydrolysis in NaOH(aq) to form porous PEO hydrogels. These hydrogels retain active functional groups following PCL removal that serve as sites for further chemical modification.
Kang
Jungmee
J
Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 66-558, Cambridge, 02139, USA.
Beers
Kenneth J
KJ
D002152:Calorimetry, Differential Scanning; D004583:Electrons; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry; D018625:Microscopy, Atomic Force / Q000379:methods; D049329:Nanostructures / Q000737:chemistry*; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D016062:Porosity; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014867:Water / Q000737:chemistry; D014965:X-Rays
D020100:Hydrogels; D011091:Polyesters; C492324:poly(epsilon-caprolactone)-poly(oxyethylene)-poly(epsilon-caprolactone); D014867:Water; D011092:Polyethylene Glycols