Hydrogenation of tyrosine derived polyarylates

Patent metadata

Field	Value
Publication number	US-10767006-B2
Application number	US-201815972855-A
Country	US
Kind code	B2
Filing date	May 7, 2018
Priority date	Jun 7, 2017
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

A method for hydrogenating tyrosine derived polyarylates includes dissolving a second polyarylate with DMF in a flask to produce a first solution. A catalyst is added to the first solution to produce a polymer solution. The polymer solution is filtered through a Celite bed to produce a filtrate. The filtrate is added to water and stirred to precipitate the polyarylate.

First claim

What is claimed is:

1. A method for synthesizing a polyarylate having the formula:

the method comprising:
dissolving a second polyarylate having the formula:

with DMF in a flask to produce a first solution;
starting a flow of nitrogen;
adding a catalyst to the first solution to produce a polymer solution;
starting a flow of hydrogen;
filtering the polymer solution through a filtration agent to produce a filtrate; and
adding the filtrate to water and stirring to precipitate the polyarylate,
wherein a first amount of the catalyst is added to the first solution to produce a first catalyst suspension,
wherein a second amount of the catalyst is added to the first catalyst suspension to produce a second catalyst suspension, and
wherein a third amount of the catalyst is added to the second catalyst suspension to produce a third catalyst suspension.

2. A method as recited in claim 1 , wherein the first amount is greater than the second amount and the second amount is greater than the third amount.

3. A method as recited in claim 1 , wherein:
the first catalyst suspension is stirred for about 5.5 hours before adding the second amount of the catalyst to the first catalyst suspension;
the second catalyst suspension is stirred overnight before adding the third amount of the catalyst to the second catalyst suspension; and
the third catalyst solution is in suspension for about 1.75 hours.

4. A method as recited in claim 1 , further comprising drying the polymer shreds under a stream of air for about 24 hours and then under vacuum.

5. A method as recited in claim 1 , wherein the first solution includes DMF and a solvent.

6. A method as recited in claim 5 , wherein the solvent comprises methanol or acetic acid.

7. A method as recited in claim 5 , wherein the solvent comprises 20% of the first solution by volume.

8. A method as recited in claim 1 , further comprising monitoring the method using a viscosity measurement.

9. A method as recited in claim 8 , further comprising adding more of the catalyst based on the viscosity measurement.

10. A method as recited in claim 8 , wherein the viscosity measurement is obtained using an online viscometer.

11. A method as recited in claim 1 , further comprising monitoring the method using infrared spectra.

12. A method as recited in claim 1 , further comprising monitoring the method by measuring toluene.

13. A method as recited in claim 1 , further adding a scavenger to remove leached catalyst.

14. A method as recited in claim 13 , wherein the scavenger is added before the polymer solution is filtered.

15. A method as recited in claim 13 , wherein the scavenger comprises a metal scavenger.

16. A method as recited in claim 1 , further adding insoluble high surface area particles to the polymer solution produced by adding the catalyst to the first solution.

17. A method as recited in claim 16 , wherein the insoluble high surface area particles comprise BaSO 4 , silica gel, ion exchange resins, or combinations thereof.

18. A method as recited in claim 1 , further comprising monitoring the method using an iodine compound to monitor the amount of dissolved catalyst, wherein the iodine compound is KI or NaI.

19. A method for synthesizing a polyarylate having the formula:

the method comprising:
dissolving a second polyarylate having the formula:

with DMF in a flask to produce a first solution, the first solution comprising DMF and a solvent, the solvent comprising methanol or acetic acid;
starting a flow of nitrogen;
adding a catalyst to the first solution to produce a polymer solution;

starting a flow of hydrogen;
filtering the polymer solution through a filtration agent to produce a filtrate; and
adding the filtrate to water and stirring to precipitate the polyarylate.

20. A method for synthesizing a polyarylate having the formula:

the method comprising:
dissolving a second polyarylate having the formula:

with DMF in a flask to produce a first solution;
starting a flow of nitrogen;
adding a catalyst to the first solution to produce a polymer solution;
adding insoluble high surface area particles to the polymer solution produced by adding the catalyst to the first solution;
starting a flow of hydrogen;
filtering the polymer solution through a filtration agent to produce a filtrate; and
adding the filtrate to water and stirring to precipitate the polyarylate.

21. A method as recited in claim 20 , wherein the insoluble high surface area particles comprise BaSO4, silica gel, ion exchange resins, or combinations thereof.

Assignees

• Tyrx Inc
• Medtronic Inc

Inventors

• Pulapura Satish
• Le Dan Thanh
• Chen Xiangji
• Lyu Suping
• Buevich Fatima

Classifications

• C08G63/6856 Primary

  Dicarboxylic acids and dihydroxy compounds · CPC title

• C08G63/91 Primary

  Polymers modified by chemical after-treatment · CPC title

• C08G63/916

  Dicarboxylic acids and dihydroxy compounds · CPC title