Rubber compositions containing whey protein
Disclosed herein are rubber compositions comprising at least one rubber, titanium oxide filler and a whey protein component, and related methods as well as tire components containing the rubber compositions disclosed herein.
1. A method for modifying the cross-linking of a titanium oxide filler-containing rubber composition, the method comprising
mixing ingredients comprising
a whey protein powder component in an amount sufficient to provide about 0.1 to about 10 phr of whey protein,
at least one rubber,
about 5 to about 200 phr of titanium oxide filler,
an amount of reinforcing silica filler of no more than 5 phr, and
a cure package,
wherein the rubber composition exhibits decreased cross-linking as measured by M H -M L of at least 10% as compared to a comparative rubber composition of the same ingredients except for lacking any whey protein and
wherein the mixing includes at least one non-productive master-batch stage conducted at a temperature of about 130 to about 200° C. during which the at least one rubber is added and the whey protein powder component is added as a powder.
2. The method of claim 1 , wherein the whey protein powder component is present in an amount sufficient to provide about 0.5 to about 5 phr of whey protein.
3. The method of claim 1 , wherein the ingredients further comprise at least one filler selected from: calcium carbonate, clay, talc, mica, wollastonite, diatomite, and barite.
4. The method of claim 1 , wherein the ingredients are free of carbon black filler.
5. The method of claim 1 , wherein a majority of the protein chains in the whey protein have a molecular weight of greater than about 10 kDaltons.
6. The method of claim 1 , wherein at least a majority by weight of the at least one rubber comprises at least one of: natural rubber, polyisoprene rubber, polybutadiene rubber, and styrene-butadiene rubber.
7. The method of claim 6 , wherein the titanium oxide filler comprises titanium dioxide.
8. The method of claim 1 , wherein the whey protein powder component comprises acid whey.
9. The method of claim 1 , wherein the whey protein powder component comprises whey protein concentrate.
10. The method of claim 1 , wherein the whey protein powder component comprises whey protein isolate.
11. A method for preparing a tire rubber composition, the method comprising
mixing ingredients comprising
a whey protein powder component in an amount sufficient to provide 0.1 to 10 phr of whey protein,
at least one rubber comprising a conjugated diene monomer-containing polymer or copolymer,
5 to 200 phr of titanium oxide filler,
an amount of reinforcing silica filler of no more than 5 phr, and
a cure package,
wherein the mixing includes at least one non-productive master-batch stage conducted at a temperature of about 130 to about 200° C. during which the at least one rubber is added and the whey protein powder component is added as a powder.
12. The method of claim 11 , wherein mixing the ingredients further comprises a final productive mixing stage conducted at a temperature between 40 and 120° C.
13. The method of claim 11 , wherein mixing the ingredients comprises kneading with a mixer or with a milled roll.
14. The method of claim 11 , wherein the whey protein powder component is present in an amount sufficient to provide about 0.5 to about 5 phr of whey protein.
15. The method of claim 11 , wherein the ingredients further comprise at least one filler selected from: calcium carbonate, clay, talc, mica, wollastonite, diatomite, and barite.
16. The method of claim 11 , wherein the ingredients are free of carbon black filler.
17. The method of claim 11 , wherein a majority of the protein chains in the whey protein have a molecular weight of greater than about 10 kDaltons.
18. The method of claim 11 , wherein at least a majority by weight of the at least one rubber comprises at least one of: natural rubber, polyisoprene rubber, polybutadiene rubber, and styrene-butadiene rubber.
19. The method of claim 11 , wherein the titanium oxide filler comprises titanium dioxide.
20. The method of claim 11 , wherein the whey protein powder component comprises acid whey.
21. The method of claim 11 , wherein the whey protein powder component comprises whey protein concentrate.
22. The method of claim 11 , wherein the whey protein powder component comprises whey protein isolate.