Engineering

Stereocenter

Diastereomer

Enantioselective synthesis

Composite material

Catalysis

Monomer

Organic chemistry

Chemistry

Polymer chemistry

Materials science

Chemical engineering

Polymerization

Polymer

Bacteria

Genetics

Tacticity

Polyhydroxyalkanoates

Biology

Science

Stereoselective polymerization of chiral or prochiral monomers is a powerful method to produce high-performance stereoregular crystalline polymeric materials. However, for monomers with two stereogenic centers, it is generally necessary to separate diastereomers before polymerization, resulting in substantial material loss and added energy cost associated with the separation and purification process. Here we report a diastereoselective polymerization methodology enabled by catalysts that directly polymerize mixtures of eight-membered diolide (8DL) monomers with varying starting ratios of chiral racemic (rac) and achiral meso diastereomers into stereosequenced crystalline polyhydroxyalkanoates with isotactic and syndiotactic stereodiblock or stereotapered block microstructures. These polymers show enhanced ductility and toughness relative to polymers of pure rac-8DL, subject to tuning by variation of the diastereomeric ratio and structure of the 8DL monomers.

Stereosequenced crystalline polyhydroxyalkanoates from diastereomeric monomer mixtures