Synthesis of -S—CH2CH2—OH telechelic polyisobutylenes and their use for the preparation of biostable polyurethanes

Patent metadata

Field	Value
Publication number	US-10301421-B2
Application number	US-201515504492-A
Country	US
Kind code	B2
Filing date	Aug 26, 2015
Priority date	Aug 26, 2014
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

Sulfur containing, hydroxyl-telechelic PIBs, hydrolytically and oxidatively resistant, biocompatible and biostable polyurethanes (PUs) made therefrom, and methods for making both are disclosed. Well-defined hydroxyl telechelic PIBs are synthesized by a thiol-ene click photochemical reaction between PIBs carrying unsaturated end groups and 2-mercaptoethanol (HS—CH 2 CH 2 —OH). This regioselective process affords HO—CH 2 CH 2 —S-PIB-S—CH 2 CH 2 —OH (abbreviated herein as HO—S-PIB-S—OH) in high yield. In some embodiments, these HO—S-PIB-S—OH polymers may be reacted with diisocyanates and a chain extender to form sulfur containing PIB-based PUs. These sulfur containing PIB-based PUs have been found to have properties and chemical stability that are very similar to that of PUs made from di-hydroxyl terminated PIBs (OH-PIB-OHs) without sulfur, but have surprisingly increased creep resistance and are easier and less expensive to make.

First claim

What is claimed is:

1. A sulfur containing polyurethane comprising a residue of a sulfur containing, hydroxyl telechelic polyisobutylene and wherein the sulfur atom of the residue of the sulfur containing, hydroxyl telechelic polyisobutylene is separated from a terminal hydroxyl group of the sulfur containing polyisobutylene by two carbon atoms and wherein the sulfur containing polyurethane has the formula:

wherein x is an integer from about 5 to about 100; y is an integer from about 5 to about 100; z is an integer from about 5 to about 100; v is an integer from about 5 to about 100.

2. The sulfur containing polyurethane of claim 1 wherein the S-C bonds in the backbone of the polymer are not susceptible to hydrolysis by acids.

3. The sulfur containing polyurethane of claim 1 wherein the residue of the sulfur containing, hydroxyl telechelic polyisobutylenes comprise from about 50 weight % to about 80 weight % of said sulfur containing polyurethane.

4. The sulfur containing polyurethane of claim 1 having a polydispersity (PDI) of from about 3.0 to about 1.1.

5. The sulfur containing polyurethane of claim 1 having a tensile strength of from about 0.5 MPa to about 40 MPa.

6. The sulfur containing polyurethane of claim 1 having a tensile elongation of from about 50% to about 500%.

7. The sulfur containing polyurethane of claim 1 having increased creep resistance relative to the corresponding PIB O —PU polymer.

8. The sulfur containing polyurethane of claim 1 wherein said sulfur containing polymer is annealed.

9. A method of making a sulfur containing polyisobutylene-based polyurethane comprising:
A. preparing a sulfur containing, hydroxyl telechelic polyisobutylene wherein the sulfur atom of the sulfur containing, hydroxyl telechelic polyisobutylene is separated from a terminal hydroxyl group of the sulfur containing polyisobutylene by two carbon atoms;
B. combining said sulfur containing, hydroxyl telechelic polyisobutylene, an isocyanate and a suitable solvent in a suitable container under an inert atmosphere and heating the combination to a temperature of from about 50° C. to about 70° C.;
C. adding a catalyst and stirring to produce a prepolymer comprising the residues of said the sulfur containing, hydroxyl telechelic polyisobutylene and said isocyanate, said prepolymer having isocyanate end groups;
D. dissolving one or more chain extender in a suitable deoxygenated solvent and adding it to the prepolymer solution of step C; and
E. reacting said prepolymer with said chain extender to produce a sulfur containing polyisobutylene-based polyurethane having the formula:

wherein x is an integer from about 5 to about 100; y is an integer from about 5 to about 100; z is an integer from about 5 to about 100; v is an integer from about 5 to about 100.

10. The method of claim 9 wherein the step of preparing comprises:
F. producing a polyisobutylene having one or more unsaturated end groups;
G. combining said polyisobutylene with 2-mercaptoethanol and a photoinitiator; and
H. exposing the combination of step G to ultra-violet light to produce a sulfur containing hydroxyl-telechelic polyisobutylene.

11. The method of claim 9 wherein said isocyanate is selected from the group consisting of 4,4′-methylenebis(phenyl isocyanate) (MDI), 4,4′-methylenebis(cyclohexyl isocyanate) (HMDI), and combinations thereof.

12. The method of claim 9 wherein said catalyst comprises dibutyltin dilaurate.

13. The method of claim 9 further comprising the step of annealing said sulfur containing polyisobutylene-based polyurethane.

Assignees

• Kennedy Joseph
• Toth Kalman
• Nugay Nihan
• Nugay Turgut
• Univ Akron

Inventors

• Kennedy Joseph
• Toth Kalman
• Nugay Nihan
• Nugay Turgut

Classifications

• C08F110/10

  Isobutene · CPC title

• C08G75/04

  from mercapto compounds or metallic derivatives thereof (C08G75/0204 takes precedence) · CPC title

• C08F2810/40

  taking place solely at one end or both ends of the polymer backbone, i.e. not in the side or lateral chains · CPC title

• C08F8/34

  Introducing sulfur atoms or sulfur-containing groups · CPC title

• C08G18/6204 Primary

  Polymers of olefins (unsaturated polymers of conjugated dienes C08G18/69) · CPC title