# US 5,707,597 A · Polyhalophosphazene solutions stable against gelation

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- Number: US 5,707,597 A
- Document ID: US5707597A
- Status: Granted
- Kind: A
- Application number: 08/747,613
- Filed: 1996-11-13
- Granted: 1998-01-13
- Earliest claimed: 1996-11-13
- Assignees: Virus Research Institute
- Inventors: Alexander K. Andrianov; Jonathan R. Sargent; Sameer S. Sule; Mark LeGolvan
- Web page: https://patentgrep.com/patent/US5707597A

## CPC

- C08G 79/025: Polyphosphazenes
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

A solution which comprises a polyphosphazene solute, such as a polyhalophosphazene solute, and a stabilizing solvent such as diglyme. Such solution enables the polyphosphazene to remain stable for extended periods of time so that such polyhalophosphazenes may be employed for further modification or use.

## Claims

### Claim 1

A solution comprising (i) a solute, said solute being a polyphosphazene; and (ii) at least one solvent, wherein said at least one solvent includes a first solvent in an amount of at least 25% by volume of the total amount of solvent, said first solvent having the following structural formula: ##STR3## wherein each of R.sub.1 and R.sub.3 is an aliphatic or aromatic hydrocarbon having from 1 to 6 carbon atoms, and each of R.sub.1 and R.sub.3 is the same or different, R.sub.2 is an aliphatic hydrocarbon having from 1 to 4 carbon atoms, and n is from 2 to 10.

### Claim 2 (depends on 1)

The solution of claim 1 wherein said polyphosphazene is a polyhalophosphazene.

### Claim 3 (depends on 2)

The solution of claim 2 wherein said polyhalophosphazene is poly(dichlorophosphazene).

### Claim 4 (depends on 1)

The solution of claim 1 wherein each of R.sub.1 and R.sub.3 is methyl.

### Claim 5 (depends on 1)

The solution of claim 1 wherein n is from 2 to 4.

### Claim 6 (depends on 5)

The solution of claim 5 wherein R.sub.2 is ethyl.

### Claim 7 (depends on 6)

The solution of claim 6 wherein said first solvent is diglyme.

### Claim 8 (depends on 1)

The solution of claim 1 wherein said at least one solvent further includes at least a second solvent selected from the group consisting of tetrahydrofuran, toluene, benzene, chlorobenzenes, monoglyme, and dioxane, and mixtures thereof.

### Claim 9 (depends on 8)

The solution of claim 8 wherein said first solvent is present in an amount of at least 50% by volume of the total amount of solvent.

### Claim 10 (depends on 9)

The solution of claim 9 wherein said first solvent is present in an amount of at least 75% by volume of the total amount of solvent.

### Claim 11 (depends on 1)

The solution of claim 1 wherein said polyphosphazene is present in said solution at a concentration of from about 0.1% (wt./vol.) to about 30% (wt./vol.).

### Claim 12 (depends on 11)

The solution of claim 11 wherein said polyphosphazene is present in said solution at a concentration of about 1% (wt./vol.) to about 10% (wt./vol.).

### Claim 13 (depends on 12)

The solution of claim 12 wherein said polyphosphazene is present in said solution in an amount of about 8% (wt./vol.).