Synthesis of crystalline polymers from cyclic diolides

Patent metadata

Field	Value
Publication number	US-10954335-B2
Application number	US-201916246302-A
Country	US
Kind code	B2
Filing date	Jan 11, 2019
Priority date	Jan 11, 2018
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Biodegradable polymers with advantageous physical and chemical properties are described, as well as methods for making such polymers. In one embodiment, a new chemical synthesis route to technologically important biodegradable poly(3-hydroxybutyrate) (P3HB) with high isotacticity and molecular weight required for a practical use is described. The new route can utilize racemic eight-membered cyclic diolide (rac-DL), meso-DL, or a rac-DL and meso-DL mixture, derived from bio-sourced dimethyl succinate, and enantiomeric (R,R)-DL and (S,S)-DL, optically resolved by metal-based catalysts. With a stereoselective racemic molecular catalyst, the ROP of rac-DL under ambient conditions produces rapidly P3HB with essentially perfect isotacticity ([mm]>99%), high crystallinity and melting temperature (Tm=171° C.), as well as high molecular weight and low dispersity (Mn=1.54×105 g/mol, Ð=1.01).

First claim

What is claimed is:

1. A highly isotactic polymer comprising Formula I:

wherein:
n is about 10 to about 10,000;
R is (C 1 -C 18 )alkyl, (C 1 -C 8 )alkenyl, (C 1 -C 8 )alkynyl, benzyl, or aryl; and
Formula I comprises at least 95% isotactic triads with respect to the stereocenters of substituents R on the polymer chain, wherein the at least 95% isotactic triads (mm) have consecutive (R) stereochemical configurations or consecutive (S) stereochemical configurations.

2. The polymer of claim 1 wherein the polymer comprises at least 99% isotactic triads with respect to the stereocenters of substituents R on polymer chain.

3. The polymer of claim 2 wherein the molecular weight M n is at least about 100 kDa.

4. The polymer of claim 1 wherein the polymer has a melting temperature, T m of at least 170° C.

5. A composition comprising polymers of claim 1 wherein the composition comprises approximately equal amounts of polymers having isotactic triads of (R) stereochemical configurations and polymers having isotactic triads of (S) stereochemical configurations.

6. The composition of claim 5 wherein the dispersity index M w /M n of the polymers is less than 1.2.

7. A copolymer comprising a polymer of claim 1 and a polyester of lactone monomers.

Assignees

• Univ Colorado State Res Found

Inventors

• Chen Eugene Y
• Tang Xiaoyan

Classifications

• B01J31/2243

  At least one oxygen and one nitrogen atom present as complexing atoms in an at least bidentate or bridging ligand · CPC title

• B01J2531/36

  Yttrium · CPC title

• C08L67/04

  Polyesters derived from hydroxycarboxylic acids, e.g. lactones (C08L67/06 takes precedence) · CPC title

• B01J2531/35

  Scandium · CPC title

• C08G63/08 Primary

  Lactones or lactides · CPC title