Energetic copolyurethane thermoplastic elastomers

A thermoplastic elastomer comprising a linear copolymer chain comprising an A block and a B block, said copolymer chain having the formula:

• HO—P—(U—P)n—OH
• wherein
• P is selected from the group consisting of
• where the
• R1 groups are the same and selected from the group consisting of —CH2N3 and —CH2ONO2;
• R2 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and o and p are each ≧1;
• and
• where the
• R3 groups are the same and are selected from the group consisting of —CH2N3 and —CH2ONO2 and the R4 groups are —CH3;
• R5 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and q and r are both ≧1
• U is selected from the group consisting of
• and
• n is 1 to 100
• wherein said A block is provided by said U moieties and said B block is provided by said P moieties and said elastomer further comprises a chain extender.

A thermoplastic elastomer comprising a linear copolymer chain comprising an A block and a B block, said copolymer chain having the formula:

• HO—P—(U—(C—U)a—P)b—U—P—OH
• wherein
• P is selected from the group consisting of
• where the
• R1 groups are the same and selected from the group consisting of —CH2N3 and —CH2ONO2;
• R2 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and o and p are each ≧1;
• and
• where the
• R3 groups are the same and are selected from the group consisting of —CH2N3 and —CH2ONO2 and the R4 groups are —CH3,
• R5 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and q and r are both ≧1
• U is selected from the group consisting of
• C is selected from the group consisting of
• and
• —OCH2—(CH2)n—CH2O— where n is 0 to 8.
• a is 1 to 100 and b is 1 to 100
• wherein said A block is provided by said U moieties and said B block is provided by said P moieties.

A thermoplastic elastomer comprising a linear copolymer chain comprising an A segment and a B segment, said copolymer chain having the formula:

• HO—P—U—(C—U)x—(P—U)y—(C—U)z—P—OH
• wherein
• P is selected from the group consisting of
• where the
• R1 groups are the same and selected from the group consisting of —CH2N3 and —CH2ONO2;
• R2 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and o and p are each ≧1:
• and
• where the
• R3 groups are the same and are selected from the group consisting of —CH2N3 and —CH2ONO2 and the R4 groups are —CH3,
• R5 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and q and r are both ≧1
• U is selected from the group consisting of
• C is selected from the group consisting of
• and
• —OCH2—(CH2)n—CH2O— where n is 0 to 8;
• x, y and z are each an integer from 1 to 100;
• wherein said A segment is provided by said U moieties and said B segment is provided by said P moieties.

A method of preparing an energetic thermoplastic elastomer comprising the steps of:

• (a) drying a dihydroxyl terminated telechelic energetic prepolymer having a functionality of two or less;
• and
• (b) polymerizing said dried energetic prepolymer with a diisocyanate at a NCO/OH ratio ranging from about 0.7 to 1.2 under dried conditions
• wherein a chain extender is added to the diisocyanate before the addition of the prepolymer or mixed simultaneously with the prepolymers and the diisocyanate.

A method of preparing an energetic thermoplastic elastomer comprising a linear copolymer chain having the formula:

• HO—P—(U—P)n—OH
• wherein
• P is selected from the group consisting of
• where the
• R1 groups are the same and selected from the group consisting of —CH2N3 and —CH2ONO2;
• R2 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and o and p are each ≧1;
• and
• where the
• R3 groups are the same and selected from the group consisting of —CH2N3 and —CH2ONO2;
• the R4 groups are —CH3
• R5 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and q and r are both ≧1
• U is selected from the group consisting of
• n is 1 to 100;
• said method comprises polymerizing a dihydroxyl terminated telechelic energetic prepolymer having a functionality of two or less selected from the group consisting of poly glycidyl azide polymer, poly 3-azidomethyl-3-methyloxethane, poly 3-nitratomethyl-3-methyloxetane, and poly glycidyl nitrate with a diisocyanate selected from the group consisting of 4,4′ methylenebis-phenyl isocyanate, toluene diisocyanate, and isophorone diisocyanate at a NCO/OH ratio ranging from about 0.7 to about 1.2 under dried conditions, and adding a chain extender to increase the hard content of the energetic thermoplastic elastomer.

A method of preparing an energetic thermoplastic elastomer having the formula:

• HO—P—(U—P)n—OH
• wherein
• P is selected from the group consisting of
• where the
• R3 and R4 groups are —CH2N3;
• R5 is selected from the group consisting of —OCH2CH2O—, —OCH2CH2CH2O— and —OCH2CH2CH2CH2O—;
• and q and r are both ≧1
• U is selected from the group consisting of
• n is 1 to 100;
• said method comprises polymerizing poly 3,3-bis(azidomethyl)oxetane with a diisocyanate selected from the group consisting of 4,4′ methylenebis-phenyl isocyanate, toluene diisocyanate and isophorone diisocyanate at a NCO/OH ratio ranging from about 0.7 to 1.2 under dried conditions and adding a chain extender to increase the hard content of said energetic thermoplastic elastomer.