Synthetic Strategy for Preparing Chiral Double-semicrystalline Polyether Block Copolymers.
We report an effective strategy for the synthesis of semi-crystalline block copolyethers with well-defined architecture and stereochemistry. As an exemplary system, triblock copolymers containing either atactic (racemic) or isotactic (RorS) poly(propylene oxide) end blocks with a central poly(ethylene oxide) mid-block were prepared by anionic ring-opening procedures. Stereochemical control was achieved by an initial hydrolytic kinetic resolution of racemic terminal epoxides followed by anionic ring-opening polymerization of the enantiopure monomer feedstock. The resultant triblock copolymers were highly isotactic (meso triads [mm]% ~ 90%) with optical microscopy, differential scanning calorimetry, wide angle x-ray scattering and small angle x-ray scattering being used to probe the impact of the isotacticity on the resultant polymer and hydrogel properties.
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
Alaina J
AJ
McGrath
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
Weichao
W
Shi
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
Christina G
CG
Rodriguez
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA ; Materials Department, University of California, Santa Barbara, CA 93106, USA ; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA.
Edward J
EJ
Kramer
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA ; Materials Department, University of California, Santa Barbara, CA 93106, USA ; Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA.
Craig J
CJ
Hawker
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
Nathaniel A
NA
Lynd