Methods for biobased derivatization of cellulosic surfaces
The present disclosure describes tunable methods of treating cellulosic materials with a composition that provides increased hydrophobicity and/or lipophobicity to such materials without sacrificing the biodegradability thereof. The methods as disclosed provide for binding of saccharide fatty acid esters on cellulosic materials, including that the disclosure provides products made by such methods. The materials thus treated display higher hydrophobicity, lipophobicity, barrier function, and mechanical properties, and may be used in any application where such features are desired.
1. A method for providing water resistance or water and lipid resistance to a substrate, the method comprising:
a) preparing a formulation for imparting a water barrier function or a water and lipid barrier function to a substrate, the formulation consisting essentially of a saccharide fatty acid ester and a binder;
b) coating a surface of the substrate with the formulation; and
c) exposing the coated substrate to heat, radiation, a catalyst, or a combination thereof to bind the saccharide fatty acid ester and the binder to the surface of the substrate,
wherein the substrate obtained in step c) exhibits a water contact angle greater than 90°.
2. The method of claim 1 , wherein the substrate obtained in step c) is lipophobic.
3. The method of claim 1 , wherein the formulation imparts the water barrier function to the substrate in the absence of any secondary hydrophobes.
4. The method of claim 1 , wherein the substrate obtained in step c) exhibits a water contact angle of at least 120°.
5. The method of claim 1 , wherein the substrate obtained in step c) exhibits an HST value of at least 65 secs.
6. The method of claim 1 , wherein the binder is selected from the group consisting of starch, protein, prolamine, polymers, polymer emulsions, PvOH, and combinations thereof.
7. The method of claim 1 , wherein the binder is selected from the group consisting of starch, protein, prolamine, PvOH, and combinations thereof.
8. The method of claim 1 , wherein the binder is PvOH.
9. The method of claim 1 , wherein the saccharide fatty acid esters comprises a sucrose soyate.
10. The method of claim 1 , wherein the saccharide fatty acid esters contain at least one saccharide and at least one aliphatic group comprising 6 to 30 carbons,
the saccharide is a disaccharide selected from the group consisting of raffinose, maltodextrose, a disaccharide comprising galactose, sucrose, a disaccharide comprising glucose, a disaccharide comprising fructose, maltose, lactose, a disaccharide comprising mannose, a disaccharide comprising erythrose, isomaltose, isomaltulose, trehalose, trehalulose, cellobiose, laminaribiose, chitobiose and combinations thereof.
11. The method of claim 10 , wherein the aliphatic group contains all saturated bonds or a mixture of saturated and unsaturated bonds.
12. The method of claim 1 , wherein the saccharide fatty acid ester is present on the substrate at a coating weight of at least 0.1 g/m 2 .
13. The method of claim 1 , wherein the saccharide fatty acid ester comprises a compound according to the following Formula I:
wherein, in Formula I, each A is independently represented by hydrogen or the following Structure I:
wherein, in each Structure I, R is independently represented by a linear, branched, or cyclic, saturated or unsaturated, aliphatic or aromatic moiety of 8 to 40 carbon atoms,
wherein at least one A in the Formula I is represented by the Structure I.
14. The method of claim 13 , wherein each A in the Formula I is the Structure I.
15. The method of claim 13 , wherein at least two A in the Formula I are represented by the Structure I, and a plurality of the R are unsaturated.
16. The method of claim 1 , wherein the substrate obtained in step c) exhibits a TAPPI T 559 KIT test value of from 3 to 12.
17. The method of claim 1 , wherein the saccharide fatty acid ester is present on the substrate at a coating weight 1.0 g/m 2 to 20 g/m 2 .