Energy absorbing blends
A composite material which is elastic, which exhibits a resistive load under deformation which increases with the rate of deformation, which is unfoamed or foamed, comminuted or uncomminuted and which comprises i) a first polymer-based elastic material and ii) a second polymer-based material, different from i), which exhibits dilatancy in the absence of i) wherein ii) is entrapped in a solid matrix of i), the composite material being unfoamed or, when foamed, preparable by incorporating ii) with i) prior to foaming.
1. A method of protecting a subject from an impact comprising
a) providing an impact protection system comprising an unfoamed composite material, the composite material being elastic and exhibiting a resistive load under deformation which increases with a rate of deformation, the composite material comprising (i) a solid matrix comprising a first polymer-based elastic material and (ii) a second polymer-based elastic material different from (i) which exhibits dilatancy in the absence of the first polymer-based elastic material, wherein the second polymer-based elastic material is entrapped in the solid matrix in an intimate admixture; and
b) placing the impact protection system on the subject to protect the subject from the impact,
wherein the intimate admixture is attainable by mixing together the first polymer-based elastic material and the second polymer-based elastic material in the semi-molten or molten state; and
wherein the composite material is associated with a textile layer or is a shaped article in the form of (a) a fiber or (b) a textile or web comprising filaments or fibers.
2. The method of claim 1 , wherein the composite material is flexible, conformable, and elastic.
3. The method of claim 1 , wherein the composite material is attainable by blending (i) and (ii) together.
4. The method of claim 1 , wherein the first polymer-based material comprises ethylene vinyl acetate (EVA) or an olefin polymer.
5. The method of claim 4 , wherein the olefin polymer comprises polypropylene or an ethylene polymer.
6. The method of claim 5 , wherein the ethylene polymer comprises high pressure polyethylene, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or high density polyethylene (HDPE).
7. The method of claim 1 , wherein the first polymer-based elastic material further comprises an elastomer.
8. The method of claim 7 , wherein the elastomer is a natural elastomer.
9. The method of claim 8 , wherein the natural elastomer comprises latex rubber.
10. The method of claim 7 , wherein the elastomer is a synthetic elastomer.
11. The method of claim 10 , wherein the synthetic elastomer comprises a silicone rubber, a polyurethane, a thermoplastic elastomer, or an ethylene propylene (EP).
12. The method of claim 11 , wherein the EP comprises ethylene propylene diene monomer (EPDM).
13. The method of claim 11 , wherein the thermoplastic elastomer comprises a polyester.
14. The method of claim 1 , wherein the second polymer-based elastic material comprises a silicone polymer exhibiting dilatant properties.
15. The method of claim 14 , wherein the silicone polymer comprises a borated siloxane polymer.
16. The method of claim 15 , wherein the borated siloxane polymer comprises a filled polyborodimethylsiloxane.
17. The method of claim 1 , wherein the composite material is comminuted.
18. The method of claim 1 , wherein the weight ratio of the second polymer-based elastic material to the first polymer-based material is 4 to 0.25.
19. The method of claim 1 , wherein the shaped article is in the form of a fiber.
20. The method of claim 1 , wherein the shaped article is a textile or web comprising filaments or fibers.
21. The method of claim 1 , wherein the composite material is associated with a textile layer.
22. The method of claim 21 , wherein the textile layer comprises a textile having elastic fibers.
23. The method of claim 1 , wherein the weight ratio of the second polymer-based elastic material to the first polymer-based elastic material is 4 to 1.
24. A method of protecting a subject from an impact comprising
a) providing an impact protection system comprising an unfoamed composite material, the composite material being elastic and exhibiting a resistive load under deformation which increases with a rate of deformation, the composite material comprising (i) a solid matrix comprising a first polymer-based elastic material and (ii) a second polymer-based elastic material different from (i) which exhibits dilatancy in the absence of the first polymer-based elastic material, wherein the second polymer-based elastic material is entrapped in the solid matrix in an intimate admixture; and
b) placing the impact protection system on the subject to protect the subject from the impact,
wherein the intimate admixture is attainable by mixing together the first polymer-based elastic material and the second polymer-based elastic material in the semi-molten or molten state; and
the first polymer-based elastic material comprises high pressure polyethylene, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or high density polyethylene (HDPE).
25. The method of claim 24 , wherein the second polymer-based elastic material comprises a silicone polymer exhibiting dilatant properties.
26. The method of claim 25 , wherein the silicone polymer comprises a borated siloxane polymer.
27. The method of claim 26 , wherein the borated siloxane polymer comprises a filled polyborodimethylsiloxane.
28. A method of protecting a subject from an impact comprising
a) providing an impact protection system comprising an unfoamed composite material, the composite material being elastic and exhibiting a resistive load under deformation which increases with a rate of deformation, the composite material comprising (i) a solid matrix comprising a first polymer-based elastic material and (ii) a second polymer-based elastic material different from (i) which exhibits dilatancy in the absence of the first polymer-based elastic material, wherein the second polymer-based elastic material is entrapped in the solid matrix in an intimate admixture; and
b) placing the impact protection system on the subject to protect the subject from the impact,
wherein the intimate admixture is attainable by mixing together the first polymer-based elastic material and the second polymer-based elastic material in the semi-molten or molten state; and
the first polymer-based elastic material further comprises a natural elastomer.
29. The method of claim 28 , wherein the natural elastomer comprises latex rubber.
30. The method of claim 28 , wherein the second polymer-based elastic material comprises a silicone polymer exhibiting dilatant properties.
31. The method of claim 30 , wherein the silicone polymer comprises a borated siloxane polymer.
32. The method of claim 31 , wherein the borated siloxane polymer comprises a filled polyborodimethylsiloxane.
33. A method of protecting a subject from an impact comprising
a) providing an impact protection system comprising an unfoamed composite material, the composite material being elastic and exhibiting a resistive load under deformation which increases with a rate of deformation, the composite material comprising (i) a solid matrix comprising a first polymer-based elastic material and (ii) a second polymer-based elastic material different from (i) which exhibits dilatancy in the absence of the first polymer-based elastic material, wherein the second polymer-based elastic material is entrapped in the solid matrix in an intimate admixture; and
b) placing the impact protection system on the subject to protect the subject from the impact,
wherein the intimate admixture is attainable by mixing together the first polymer-based elastic material and the second polymer-based elastic material in the semi-molten or molten state; and
the first polymer-based elastic material further comprises a synthetic elastomer comprising a polyester or ethylene propylene diene monomer (EPDM).
34. The method of claim 33 , wherein the synthetic elastomer comprises a polyester.
35. The method of claim 33 , wherein the synthetic elastomer comprises EPDM.
36. The method of claim 33 , wherein the second polymer-based elastic material comprises a silicone polymer exhibiting dilatant properties.
37. The method of claim 36 , wherein the silicone polymer comprises a borated siloxane polymer.
38. The method of claim 37 , wherein the borated siloxane polymer comprises a filled polyborodimethylsiloxane.