Increased water resistance of paper treated with amylose-fatty ammonium salt inclusion complexes

Authors: Fanta, George; Felker, Frederick; Hay, William; Selling, Gordon

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2017
Publication Date: 5/22/2017
Publication URL: https://handle.nal.usda.gov/10113/5684917
Citation: Fanta, G.F., Felker, F.C., Hay, W.T., Selling, G.W. 2017. Increased water resistance of paper treated with amylose-fatty ammonium salt inclusion complexes. Industrial Crops and Products. 105:231-237.

Interpretive Summary: Paper is made from wood pulp, and is comprised mostly of cellulose fibers that are easily wettable and have little water resistance. Therefore, many chemical treatments and additives are applied to paper to make it more water resistant for many applications, including printing and packaging. Most of these treatments require materials and processes that are toxic, hazardous, non-biobased, or not environmentally sustainable. This study was undertaken to determine whether corn starch complexes, made by passing starch through a steam jet cooker and combining it with a vegetable oil derivative, could be applied to untreated paper to impart water resistance. By measuring the contact angle of applied water droplets and the extent of water uptake with time, it was shown that the starch complexes conferred significant water resistance to the paper. The effect was enhanced by providing an additional treatment with a diluted base solution. The presence of starch on the treated paper was shown by iodine vapor staining. This information will be useful to producers of paper products desiring a simple, environmentally friendly alternative method for making paper water resistant.

Technical Abstract: Amylose inclusion complexes were prepared from high amylose corn starch and the HCl salts of hexadecylamine and octadecylamine. Solutions of the complexes were applied to paper at concentrations of 2-4%. After the treated papers were dried, sodium hydroxide solution was applied to convert the adsorbed amine salts of the complexes to insoluble amines, rendering the paper bearing the adsorbed complexes hydrophobic. SEM showed that the amylose complexes were uniformly deposited onto the cellulose fibers with no visible particles. Increased resistance of treated papers to the penetration of water was indicated by an increase in the contact angles of water droplets and the number of seconds for total absorption of the droplets. The treated papers also absorbed a lower percentage of water than the untreated samples, with the greatest water resistance observed in papers treated with the C16 amylose-hexadecylammonium chloride inclusion complex. The materials used for treatment are non-toxic, biobased, and biodegradable.