ADHESIVE WITH PROTEIN
Adhesives, methods of producing adhesives, and cellulosic products formed with the adhesive are provided. In an exemplary embodiment, an adhesive includes a protein, a first reactant that has a plurality of isocyanate moieties, and a second reactant with one or more of a chlorohydrin moiety, an azetidinium moiety, and an epoxy moiety. The protein is reacted with the first reactant to form a functionalized protein intermediate, and the functionalized protein intermediate is then reacted with the second reactant.
1 . An adhesive product comprising:
a protein;
a first reactant comprising a plurality of isocyanate moieties;
a second reactant comprising one or more of a chlorohydrin moiety, an azetidinium moiety, and an epoxy moiety; and
wherein the protein is reacted with the first reactant to form a functionalized protein intermediate, and wherein the functionalized protein intermediate is reacted with the second reactant.
2 . The adhesive product of claim 1 , further comprising:
water, wherein the water is present in the adhesive product at from about 30 to about 70 weight percent, based on a total weight of the adhesive product.
3 . The adhesive product of claim 1 , wherein:
the protein is present in the adhesive product at from about 50 to about 90 percent by weight of solids, the first reactant is present in the adhesive product at from about 1 to about 10 percent by weight of the solids, and the second reactant is present in the adhesive product at from about 10 to about 40 percent by weight of the solids, all based on a total weight of the solids of the adhesive product.
4 . The adhesive product of claim 1 , wherein:
the second reactant is polyamideamine epichlorohydrin.
5 . The adhesive product of claim 4 , wherein:
the first reactant is selected from the group of hexamethylene diisocyanate, poly methylene diphenyl diisocyanate, methylene bis(phenyl isocyanate), toluene isocyanate, naphthalene diisocyanate, isophorone diisocyanate, and combinations thereof.
6 . The adhesive product of claim 4 , wherein the first reactant is hexamethylene diisocyanate.
7 . The adhesive product of claim 1 , wherein the functionalized protein intermediate is formed at a pH of 7 or greater.
8 . The adhesive product of claim 1 , wherein:
the protein is a soy protein derived from soy flour, soy concentrate, or soy isolate.
9 . A cellulosic product comprising:
a first cellulosic substrate;
a second cellulosic substrate;
an adhesive adhering the first cellulosic substrate to the second cellulosic substrate, wherein the adhesive comprises a protein, a first reactant, and a second reactant, wherein the first reactant comprises a plurality of isocyanate moieties, the second reactant comprises one or more of a chlorohydrin moiety, an azetidinium moiety, and an epoxy moiety, and wherein the protein was reacted with the first reactant to produce a functionalized protein intermediate prior to reacting with the functionalized protein intermediate with the second reactant.
10 . The cellulosic product of claim 9 , wherein:
the first reactant is selected from the group of hexamethylene diisocyanate, poly methylene diphenyl diisocyanate, methylene bis(phenyl isocyanate), toluene isocyanate, naphthalene diisocyanate, isophorone diisocyanate, and combinations thereof, and the second reactant is polyamideamine epichlorohydrin.
11 . A method of producing an adhesive, the method comprising the steps of:
combining a protein with a first reactant to produce a functionalized protein intermediate, wherein the first reactant comprises a plurality of isocyanate moieties;
combining the functionalized protein intermediate with a second reactant to produce the adhesive, wherein the second reactant comprises one or more of a chlorohydrin moiety, an azetidinium moiety, and an epoxy moiety.
12 . The method of claim 11 , wherein:
combining the protein with the first reactant comprises combining the protein with the first reactant in an aqueous medium at a pH of about 7 or greater.
13 . The method of claim 11 , wherein:
combining the protein with the first reactant comprises combining the protein with the first reactant in an aqueous medium at a pH of about 9 or greater.
14 . The method of claim 11 , wherein:
combining the protein with the first reactant comprises combining the protein with the first reactant at a protein to first reactant weight ratio of from about 1/100 to about 15/100.
15 . The method of claim 11 , wherein:
combining the functionalized protein intermediate with the second reactant comprises combining the functionalized protein intermediate with the second reactant wherein the second reactant is polyamideamine epichlorohydrin.
16 . The method of claim 15 , wherein:
combining the protein with the first reactant comprises combining the protein with the first reactant wherein the first reactant is selected from the group of hexamethylene diisocyanate, poly methylene diphenyl diisocyanate, methylene bis(phenyl isocyanate), toluene isocyanate, naphthalene diisocyanate, isophorone diisocyanate, and combinations thereof.
17 . The method of claim 15 , wherein:
combining the protein with the first reactant comprises combining the protein with the first reactant wherein the first reactant is hexamethylene diisocyanate.
18 . The method of claim 11 , further comprising:
dispersing the protein in water prior to combining the protein with the first reactant; and
adjusting a pH of the protein dispersed in the water to about 7 or greater prior to combining the protein with the first reactant.
19 . The method of claim 18 , further comprising:
adding a defoamer to the protein intermediate prior to combining the protein with the first reactant.
20 . The method of claim 11 further comprising:
adhering a first cellulosic substrate to a second cellulosic substrate with the adhesive