Protein-containing adhesives, and manufacture and use thereof
The invention provides protein adhesives and methods of making and using such adhesives. The protein adhesives contain ground plant meal or an isolated polypeptide composition obtained from plant biomass.
1. An adhesive composition comprising:
(a) from about 1% to about 90% (w/w) of a reactive prepolymer;
(b) ground plant meal in an amount sufficient to disperse the reactive prepolymer in an aqueous medium, wherein the ground plant meal is derived from sunflower, rapeseed, canola, castor, soy, camelina, jatropha, mallow, peanuts, sugarcane bagasse, tobacco, whey, or a combination thereof; the ground plant meal being present in an amount ranging from about 1% (w/w) to about 50% (w/w) of the adhesive composition; and
(c) a formaldehyde scavenging agent and/or an agent that improves moisture resistance.
2. The composition of claim 1 , wherein the ground plant meal has a particle size in the range of from about 1 μm to about 200 μm.
3. The composition of claim 1 , wherein the ground plant meal is present in an amount from about 5% to about 35% (w/w) of the adhesive composition.
4. The composition of claim 1 , wherein (i) the formaldehyde scavenging agent has the formula RN(H)C(O)N(H)R, wherein R represents independently for each occurrence H, alkyl, aryl, or aralkyl, and (ii) the agent that improves moisture-resistance is a silicone.
5. The composition of claim 1 , wherein the reactive prepolymer is a polyisocyanate-based prepolymer.
6. The composition of claim 1 , wherein the reactive prepolymer is an organic polyisocyanate selected from the group consisting of polymeric diphenylmethane diisocyanate (PMDI), 4,4′-methylenediphenyl, diisocyanate (4,4′-MDI), 2,4-methylenediphenyl, diisocyanate (2,4-MDI), or a combination thereof.
7. The composition of claim 1 , further comprising water.
8. A method of bonding a first article to a second article comprising:
(a) depositing on a surface of the first article the adhesive composition of claim 1 thereby to create a binding area; and
(b) contacting the binding surface with a surface of the second article thereby to bond the first surface to the second surface.
9. The method of claim 8 , further comprising the step of, after step (b), permitting the adhesive composition to cure.
10. The method of claim 9 , wherein curing comprises applying pressure, heat or both pressure and heat.
11. The method of claim 8 , wherein the first article, the second article or both the first and second articles are lignocellulosic materials, or composite materials containing lignocellulosic material.
12. The composition of claim 4 , wherein the formaldehyde scavenging agent is H 2 NC(O)NH 2 .
13. The composition of claim 1 , wherein the formaldehyde scavenging agent is present in an amount from about 1% to about 50% (w/w) of the adhesive composition.
14. The composition of claim 1 , wherein the formaldehyde scavenging agent is present in an amount from about 2% to about 30% (w/w) of the adhesive composition.
15. The composition of claim 7 , wherein the water is present in an amount from about 30% (w/w) to about 60% (w/w) of the adhesive composition.