Methods of forming flexible structures for a rocket motor assembly, related flexible structures, and related assemblies including the flexible structures

Patent metadata

Field	Value
Publication number	US-2016245233-A1
Application number	US-201514629297-A
Country	US
Kind code	A1
Filing date	Feb 23, 2015
Priority date	Feb 23, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

A method of forming a flexible structure for a rocket motor assembly comprises forming a polysiloxane composition comprising at least two different silicone materials. A preliminary structure is formed from the polysiloxane composition. The preliminary structure is cured to crosslink at least a portion of different polysiloxane chains of the preliminary structure. A flexible structure for a rocket motor assembly, a flexible assembly for a rocket motor assembly, a moveable thrust nozzle assembly for a rocket motor assembly, and a rocket motor assembly are also described.

First claim

What is claimed is:

1 . A method of forming a flexible structure for a rocket motor assembly, comprising:
forming a polysiloxane composition comprising at least two different silicone materials; forming a preliminary structure from the polysiloxane composition; and curing the preliminary structure to crosslink at least a portion of different polysiloxane chains of the preliminary structure.

2 . The method of claim 1 , wherein forming a polysiloxane composition comprises selecting each of the at least two different silicone materials to independently comprise a polysiloxane compound having the following chemical structure:

where each R independently comprises hydrogen, an aliphatic group, or a cyclic group;
each M independently comprises a vinyl group, a silanol group, an allyl group, a vinylcyclohexyl group, a styryl group, or a propargyl group; and
n comprises an integer from 2 to 10,000.

3 . The method of claim 2 , wherein selecting each of the at least two different silicone materials to independently comprise a polysiloxane compound comprises selecting the at least two different silicone materials to comprise different grades of the same polysiloxane.

4 . The method of claim 2 , wherein selecting each of the at least two different silicone materials to independently comprise a polysiloxane compound comprises:
selecting one of the at least two different silicone materials to comprise a first polysiloxane compound; and selecting another of the at least two different silicone materials to comprise a second polysiloxane compound having a different functional group than the first polysiloxane compound.

5 . The method of claim 2 , wherein selecting each of the at least two different silicone materials to independently comprise a polysiloxane compound comprises independently selecting the polysiloxane compound of each of the at least two different silicone materials to have a polymer backbone comprising repeating units of dimethylsiloxane, methylethylsiloxane, methylphenylsiloxane, diethylsiloxane, ethylphenylsiloxane, or diphenylsiloxane.

6 . The method of claim 2 , wherein selecting each of the at least two different silicone materials to independently comprise a polysiloxane compound comprises independently selecting the polysiloxane compound of each of the at least two different silicone materials to comprise a vinyl-terminated polydimethylsiloxane.

7 . The method of claim 2 , wherein the polysiloxane composition further comprises at least one curing/crosslinking agent.

8 . The method of claim 2 , wherein forming a polysiloxane composition comprises forming the polysiloxane composition to have a Shore A hardness less than about 24.

9 . The method of claim 2 , wherein forming a preliminary structure from the polysiloxane composition comprises molding the polysiloxane composition into the preliminary structure.

10 . The method of claim 2 , wherein curing the preliminary structure to crosslink at least a portion of different polysiloxane chains of the preliminary structure comprises subjecting the preliminary structure to at least one of elevated temperatures and elevated pressures for a sufficient period of time to form a cured polysiloxane composition having a shear modulus less than about 26 psi.

11 . A flexible structure for a rocket motor assembly, comprising a shaped, cured polysiloxane composition comprising crosslinked polysiloxane chains of at least two different silicone materials.

12 . The flexible structure of claim 11 , wherein the shaped, cured polysiloxane composition has a shear modulus less than about 26 psi.

13 . The flexible structure of claim 11 , wherein the shaped, cured polysiloxane composition exhibits a substantially annular shape.

14 . The flexible structure of claim 11 , wherein the shaped, cured polysiloxane composition comprises a first polysiloxane compound crosslinked to a second polysiloxane compound, the first polysiloxane compound and the second polysiloxane compound comprising different grades of the same polysiloxane.

15 . The flexible structure of claim 11 , wherein the shaped, cured polysiloxane composition comprises a first polysiloxane compound crosslinked to a second polysiloxane compound, the first polysiloxane compound comprising at least one different functional group than the second polysiloxane compound.

16 . A flexible assembly for a rocket motor assembly, comprising:
a first substrate; a second substrate overlying the first substrate; and a lamination comprising an alternating sequence of flexible structures and rigid structures extending between the first substrate and the second substrate, at least one of the flexible structures comprising a cured polysiloxane composition comprising crosslinked polysiloxane chains of at least two different silicone materials.

17 . The flexible assembly of claim 16 , wherein each of the flexible structures has substantially the same shear modulus.

18 . The flexible assembly of claim 16 , wherein at least one of the flexible structures has a different shear modulus than at least one other of the flexible structures.

19 . The flexible assembly of claim 16 , wherein each of the flexible structures independently has a shear modulus less than about 26 psi.

20 . The flexible assembly of claim 16 , wherein each of the flexible structures comprises the cured polysiloxane composition.

21 . The flexible assembly of claim 16 , wherein at least one other of the flexible structures comprises another cured polysiloxane composition comprising crosslinked polysiloxane chains of at least two other different silicone materials.

22 . A moveable thrust nozzle assembly for a rocket motor assembly, comprising:
a fixed housing; and at least one flexible assembly coupled to and circumscribing a portion of the fixed housing and comprising:
an end-ring; and
a lamination comprising an alternating sequence of flexible structures and rigid structures extending between the fixed housing and the end-ring, at least one of the flexible structures comprising a cured polysiloxane composition comprising crosslinked polysiloxane chains of at least two different silicone materials.

23 . The moveable thrust nozzle assembly of claim 22 , wherein each of the flexible structures of the lamination independently has a shear modulus less than about 26 psi.

24 . The moveable thrust nozzle assembly of claim 23 , wherein each of the flexible structures of the lamination has substantially the same shear modulus.

25 . The moveable thrust nozzle assembly of claim 24 , wherein each of the flexible structures of the lamination comprises the cured polysiloxane composition.

26 . The rocket motor assembly, comprising:
at least one stage comprising:
a vessel containing a propellant structure; and
a moveable thrust nozzle assembly connected to an end of the vessel and comprising:
a fixed housing; and
a flexible assembly coupled to and circumscribing a portion of the fixed housing and comprising:
an end-ring; and
a lamination comprising an alternating sequence of flexible structures and rigid structures extending between the fixed housing and the end-ring, at least one of the flexible structures comprising a cured polysiloxane composition comprising crosslinked polysiloxane chains

Assignees

• Orbital Atk Inc

Inventors

• Gajiwala Himansu M
• Hall Steven B

Classifications

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L83/04

  Polysiloxanes · CPC title

• F02K9/84 Primary

  using movable nozzles · CPC title

• B32B2307/542

  Shear strength · CPC title

• B32B2307/546

  Flexural strength; Flexion stiffness · CPC title