Impact protection material and method of making the same
The present invention provides new impact protection materials and the method of making the same. More specifically, the impact protection materials are polymer-based shear-thickening composite comprising a non-shear-thickening polymer matrix material and one or more shear-thickening materials. Preferably, the non-shear-thickening polymer matrix material is in an amount from approximately 5 weight percent to approximately 90 weight percent with the balance being one or more shear-thickening materials. The first type of the one or more shear-thickening materials is sol-gel based shear-thickening material in which small inorganic particles are connected in a gel network; the second type is polymer-based shear-thickening material in which polymer chains form network. Compared to the existing shear-thickening materials, the present shear-thickening materials have different molecular structure and formulation and possess properties of good impact protection and good stability.
1. A polymer-based shear-thickening composite comprising a non-shear-thickening polymer matrix material in an amount from approximately 5 weight percent to approximately 90 weight percent with the balance being one or more shear-thickening materials comprising a sol-gel shear-thickening material in which inorganic particles formed from a precursor are connected in a gel network;
wherein the one or more shear-thickening materials further comprise a polymer-based shear-thickening material comprising polyborodimethylsiloxane with two or more Si—O—B—(OH) 2 groups represented by the following formula:
wherein the ratio of m:n is 168-700:5.3-6.1, Me is methyl group.
2. The polymer-based shear-thickening composite according to claim 1 , wherein the inorganic particles are selected from silica, titania, alumina, or calcium carbonate.
3. The polymer-based shear-thickening composite according to claim 1 , wherein the inorganic particles are formed from precursors selected from tetraethyl orthosilicate, titanium isopropoxide, or aluminum nitrate.
4. The polymer-based shear-thickening composite according to claim 3 , wherein said tetraethyl orthosilicate is in a concentration of 0.1 to 1.0 mol/L.
5. The polymer-based shear-thickening composite according to claim 3 , wherein said titanium isopropoxide is in a concentration of 0.1 to 0.8 mol/L.
6. The polymer-based shear-thickening composite according to claim 3 , wherein said aluminum nitrate is in a concentration of 0.2 to 0.6 mol/L.
7. The polymer-based shear-thickening composite according to claim 1 , wherein the non-shear-thickening polymer material is a thermoplastic polymer material.
8. The polymer-based shear-thickening composite according to claim 1 , wherein the non-shear-thickening polymer material is a thermoset polymer material.
9. The polymer-based shear-thickening composite according to claim 1 , wherein the non-shear-thickening polymer material includes both thermoplastic and thermoset polymer materials.
10. The polymer-based shear-thickening composite according to claim 1 , further comprising a foaming agent such that the polymer-based shear-thickening composite is a foam.
11. The polymer-based shear-thickening composite according to claim 1 , wherein the sol-gel shear-thickening material is dispersed into a rubber and then cured to form the composite.
12. The polymer-based shear-thickening composite according to claim 1 , wherein the sol-gel shear-thickening material is dispersed into a thermoplastic to form the composite.
13. The polymer-based shear-thickening composite according to claim 1 , wherein the sol-gel shear-thickening material is dispersed into oligomer or monomer precursor of the non-shear-thickening polymer followed by reaction to form the composite.
14. The polymer-based shear-thickening composite according to claim 1 , wherein the non-shear-thickening polymer matrix material forms a core-shell structure around the sol-gel shear-thickening material.
15. The polymer-based shear-thickening composite according to claim 1 , wherein the polyborodimethylsiloxane with two or more Si—O—B—(OH) 2 groups is synthesized by reacting boric acid with polydimethylsiloxane-co-methylhydrosiloxane via dehydrogenation or synthesized by reacting silicone rubber with boric acid.
16. A polymer-based shear-thickening material having the following chemical formula:
wherein the ratio of m:n is 168-700:5.3-6.1; Me is methyl group.
17. The polymer-based shear-thickening material of claim 16 , wherein said material is synthesized by reacting boric acid with polydimethylsiloxane-co-methylhydrosiloxane via dehydrogenation.
18. The polymer-based shear-thickening material of claim 17 , wherein polydimethylsiloxane-co-methylhydrosiloxane is trimethylsilyl terminated polydimethylsiloxane-co-methylhydrosiloxane.
19. The polymer-based shear-thickening material of claim 17 , wherein impact force reduction of said polymer-based shear-thickening material is tunable by varying the molecular weight of silane added during reaction between boric acid and polydimethylsiloxane-co-methylhydrosiloxane via dehydrogenation.
20. The polymer-based shear-thickening material of claim 16 , wherein polymer-based shear-thickening material is self-healed or self-repaired.