摘要 |
Syndiotactic poly(lactic acid) is formed by polymerization involving a cleavage of the same oxygen-acyl bond in a series of meso-lactide molecules to form polymer containing a series of units with stereocenters wherein adjacent stereocenters are of the opposite stereochemistry. The mechanism is catalyzed by chiral metal alkoxides that afford stereocontrol such as those formed by reactingor the opposite enantiomer with Al(OR)3 where R is straight chain or branched alkyl containing 1 to 20 carbon atoms, e.g., methyl or isopropyl, in solvent, with subsequent evaporation of solvent in vacuo.
|