Thermoplastic cycloaliphatic polyamide matrix resins for next-generation energy absorbing applications

Patent metadata

Field	Value
Publication number	US-11059746-B2
Application number	US-201514822396-A
Country	US
Kind code	B2
Filing date	Aug 10, 2015
Priority date	Aug 10, 2015
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

Provided are materials that include one or more cycloaliphatic polyamides integrated into or coated onto one or more structural fibers such as polyethylene fibers, aramid-fibers, glass fibers or carbon fibers. The resulting materials may be incorporated into composite articles suitable for use as protective equipment or structural layers.

First claim

We claim:

1. A helmet that decreases back face deflection when engaged by a projectile, wherein the helmet comprises:
a first layer; and
a second layer on said first layer, said second layer comprising a thermoplastic cycloaliphatic polyamide matrix surrounding a woven fabric wherein back face deflection when engaged by a projectile is reduced based on
a moderate dynamic strain-rate hardening of the poly(urethane urea) and

a dynamic strengthening response of the cycloaliphatic polyamide via a transition between transient isomer conformations of the cycloaliphatic moiety.

2. The helmet of claim 1 wherein said thermoplastic cycloaliphatic polyamide is amorphous and saturated.

3. The helmet of claim 1 wherein said composite material excludes resin absent intermolecular hydrogen bonding.

4. The helmet of claim 1 excluding polycarbonate.

5. The helmet of claim 1 wherein said thermoplastic cycloaliphatic polyamide comprises a structure as a result of a stoichiometric reaction between a diamine and a diacid.

6. The helmet of claim 5 wherein said diamine is selected from the group consisting of: hexamethylenediamine; 1,4-phenyl-diamine (para-phenylenediamine); 1,3-phenyl-diamine (m-phenylenediamine); 1,4-diaminocyclohexane; 1,3-diaminocyclohexane; m-xylylenediamine; 4,4′-methylenebis(cyclohexylamine); 2,2,4-trimethyl hexamethylene diamine; 2,4,4-trimethyl hexamethylene diamine; and any mixture thereof.

7. The helmet of claim 5 wherein said diacid is selected from the group consisting of: terephthalic acid; isophthalic acid; succinic acid; glutaric acid; adipic acid; sebacic acid; dodecanedioic acid; azelaic acid; trimethyl adipic acid; 1,4-cyclohexanedicarboxylic acid; 1,3-cyclohexanedicarboxylic acid; and any mixture thereof.

8. The helmet of claim 1 wherein said poly(urethane urea) is formed of 4,4′-dicyclohexylmethane diisocyanate, diethyltoluenediamine, and poly(tetramethylene oxide).

9. The helmet of claim 1 wherein said first layer is positioned outside of said second layer.

10. The helmet of claim 1 , wherein said cycloaliphatic polyamide is characterized by compressive flow stress values at strain rates of 2,200 per second that are higher in comparison with compressive flow stress values at strain rates of 0.01 per second.

11. A helmet that decreases back face deflection when engaged by a projectile, wherein the helmet comprises:
a first layer; and
a second layer on said first layer, said second layer comprising a thermoplastic cycloaliphatic polyamide matrix surrounding a woven fabric wherein back face deflection when engaged by a projectile is reduced based on
a moderate dynamic strain-rate hardening of the poly(urethane urea) and a dynamic strengthening response of the cycloaliphatic polyamide via a transition between transient isomer conformations of the cycloaliphatic moiety
further comprising pads.

Assignees

• Us Army Res Lab
• America as represented by the Secretary of the Army

Inventors

• Hsieh Alex J
• Chantawansri Tanya L

Classifications

• F41H5/0485

  all the layers being only fibre- or fabric-reinforced layers · CPC title

• C08J5/042

  with carbon fibres · CPC title

• C08J5/043

  with glass fibres · CPC title

• D06M15/564

  Polyureas, polyurethanes or other polymers having ureide or urethane links; Precondensation products forming them · CPC title

• D06M17/00

  Producing multi-layer textile fabrics · CPC title