# US 11,028,215 B2 · Dopant-free conductive bioelastomers

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,028,215 B2
- Document ID: US11028215B2
- Status: Granted
- Kind: B2
- Application number: 16/073,229
- Filed: 2017-02-15
- Published: 2019-01-31
- Granted: 2021-06-08
- Earliest claimed: 2016-02-15
- Assignees: Board of Regents, The University of Texas System
- Applicants: Board of Regents, the University of Texas System
- Inventors: Yi Hong
- Web page: https://patentgrep.com/patent/US11028215B2

## CPC

- C08G 18/348: {Hydroxycarboxylic acids}
- C08G 18/0823: {containing carboxylate salt groups or groups forming them}
- C08G 18/244: {tin salts of carboxylic acids}
- C08G 18/4277: {Caprolactone and/or substituted caprolactone}
- C08G 18/6659: {with compounds of group C08G18/34}
- C08G 18/73: acyclic
- C08G 18/771: {oxygen}
- C08G 2230/00: Compositions for preparing biodegradable polymers
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

The present invention provides dopant-free conductive elastomeric polyurethanes that have broad biomedical application, including smart drug delivery, electronics and biomedicine. In various embodiments, a dopant-free conductive, elastomeric polyurethane is designed by covalently conjugating biodegradable segment, conductive segment and dopant molecule into one polymer chain. The dopant-free conductive polyurethanes according to various embodiments of the invention exhibit attractive mechanical properties, including bending, knotting, stretching and recoiling. The biodegradable, conductive elastomer also exhibit good electroactivity and electrical stability without extra dopant involvement.

## Claims

### Claim 1

A dopant free conductive polyurethane elastomer (DCPU) comprising polymeric diol (PD), diisocyanate (DI), bishydroxy acid (BHA), and aniline oligomer (AO) having a formula of
—(CO—NH—DI—NH—CO)n—(O—PD—O)x—(CO—NH—DI—NH—CO)n—(NH—AO—NH)z—(CO—NH—DI—NH—CO)m—(O—BHA—O)y—(CO—NH—DI—NH—CO)m—
wherein PD represents a reaction residue of the polymeric diol, excluding the terminal hydroxyl groups of the polymeric diol:
wherein DI represents a reaction residue of the diisocyanate, excluding the terminal isocyanate groups of the diisocyanate;
wherein BHA represents a reaction residue of the bishydroxy acid, excluding the terminal hydroxyl groups of the bishydroxy acid;
AO represents a reaction residue of the aniline oligomer, excluding the terminal amine groups of the aniline oligomer; and
wherein the ratio between x:y:(n+m):z is in the range of 1.9:0.1:4:1 and 1:1:4:1.

### Claim 2 (depends on 1)

The elastomer of claim 1, wherein said polymeric diol is selected from polycaprolactone (PCL), poly (trimethylene carbonate) (PTMC), poly (hexamethylene carbonate), poly (lactide- co-caprolactone) (PLC), poly (δ-valerolactone-co-caprolactone) (PVCL), and poly ethylene glycol (PEG) containing triblock copolymer diols of PCL-PEG-PCL, PTMC-PEG-PTMC, PVCL-PEG-PVCL, or PLC-PEG-PCL.

### Claim 3 (depends on 1)

The elastomer of claim 1, wherein said aniline oligomers is selected from the group consisting of aniline trimer, aniline tetramer, aniline pentamer, aniline hexamer, aniline heptamer, and aniline octamer.

### Claim 4 (depends on 1)

The elastomer of claim 1, wherein said diisocyanate is selected from the group consisting of butane diisocyanate (BDI), hexamethylene diisocyanate (HDI), and L-lysine diisocyanate.

### Claim 5 (depends on 1)

The elastomer of claim 1, wherein said bishydroxy acid is selected from dimethylolpropionic acid (DMPA) and 2,2-Bis (hydroxymethyl)butyric acid.

### Claim 6 (depends on 1)

The elastomer of claim 1, wherein the ratio between x:y:(n+m):z is in the range of 1.8:0.2:4:1 and 1.4:0.6:4:1.

### Claim 7 (depends on 1)

The elastomer of claim 1, having a conductivity of at least 10−5 to 10−3S/cm.

### Claim 8 (depends on 1)

The elastomer of claim 1, wherein the conductivity of the elastomer does not change significantly after 14 days enzymatic degradation, or with electronic charge for 150 h.

### Claim 9 (depends on 1)

The elastomer of claim 1, wherein the elastomer has more than 99% instant elastic recovery after at least 3 to 10 cycles stretching at 10% strain.

### Claim 10 (depends on 1)

The elastomer of claim 1, wherein the elastomer is biodegradable.

### Claim 11

A dopant free conductive polyurethane elastomer (DCPU) comprising polycaprolactone diol (PCL), hexamethylene diisocyanate (HDI), dimethylolpropionic acid (DMPA), and aniline trimer (A3) having a formula of
—(CO—NH—HDI—NH—CO)n—(O—PCL—O)x—(CO—NH—HDI—NH—CO)n—(NH—A3—NH)z—(CO—NH—HDI—NH—CO)m—(O—DMPA—O)y—(CO—NH—HDI—NH—CO)m—
wherein PCL represents a reaction residue of polycaprolactone diol, excluding the terminal hydroxyl groups of the polycaprolactone diol;
wherein HDI represents a reaction residue of hexamethylene diisocyanate, excluding the terminal isocyanate groups of the hexamethylene diisocyanate;
wherein DMPA represents a reaction residue of dimethylolpropionic acid, excluding the terminal hydroxyl groups of the dimethylolpropionic acid;
wherein A3 represents a reaction residue of an aniline trimer, excluding the terminal amine groups of the aniline trimer; and
wherein the ratio between x:y:(n+m):z is in the range of 1.8:0.2:4:1 and 1.4:0.6:4:1.

### Claim 12 (depends on 10)

The elastomer of claim 10, having a conductivity of at least 10−5 to 10−3S/cm and the conductivity of the elastomer does not change significantly after 14 days enzymatic degradation.

### Claim 13 (depends on 10)

The elastomer of claim 10, wherein the elastomer has more than 99% instant elastic recovery after at least 3 to 10 cycles stretching at 10% strain.

### Claim 14

A method for synthesizing a dopant free conductive polyurethane elastomer (DCPU) comprising polymeric diol (PD), diisocyanate (DI), bishydroxy acid (BHA), and aniline oligomer (AO) having a formula of
—(CO—NH—DI—NH—CO)n—(O—PD—O)x—(CO—NH—DI—NH—CO)n—(NH—AO—NH)z—(CO—NH—DI—NH—CO)m—(O—BHA—O)y—(CO—NH—DI—NH—CO)m—,
the method comprising:
a. reacting the polymer diol (PD), the bishydroxy acid (BHA), and the diisocyanate (DI) to form a product mixture that comprises a PD containing diisocyanate and a BHA containing diisocyanate; and
b. reacting the product of step a with the aniline oligomer (AO) to form the dopant free conductive polyurethane elastomer,
wherein the amount of PD, BHA, DI, and AO used is adjusted such that the ratio between x:y:(n+m):z is in the range of 1.9:0.1:4:1 and 1:1:4:1.

### Claim 15 (depends on 14)

The method of claim 14, wherein said polymeric diol is selected from polycaprolactone (PCL), poly (trimethylene carbonate) (PTMC), poly (hexamethylene carbonate), poly (lactide- co-caprolactone) (PLC), poly (δ-valerolactone-co-caprolactone) (PVCL), and poly ethylene glycol (PEG) containing triblock copolymer diols of PCL-PEG-PCL, PTMC-PEG-PTMC, PVCL-PEG-PVCL, or PLC-PEG-PCL.

### Claim 16 (depends on 14)

The method of claim 14, wherein said aniline oligomers is selected from the group consisting of aniline trimer, aniline tetramer, aniline pentamer, aniline hexamer, aniline heptamer, and aniline octamer.

### Claim 17 (depends on 14)

The method of claim 14, wherein said diisocyanate is selected from the group consisting of butane diisocyanate (BDI), hexamethylene diisocyanate (HDI), and L-lysine diisocyanate.

### Claim 18 (depends on 14)

The method of claim 14, wherein said bishydroxy acid is selected from dimethylolpropionic acid (DMPA) and 2,2-Bis (hydroxymethyl)butyric acid.

### Claim 19 (depends on 14)

The method of claim 14, wherein the polymer diol is polycaprolactone diol (PCL), the diisocyanate is hexamethylene diisocyanate (HDI), the aniline oligomer is aniline trimer (A3), and the bishydroxy acid is DMPA.

### Claim 20 (depends on 19)

The method of claim 19, wherein the ratio between x:y:(n+m):z is in the range of 1.8:0.2:4:1 and 1.4:0.6:4:1.