Sustainable film-forming biopolymers and their formulation for naturally-derived hair styling products

Hair styling products are typically based on synthetic polymers and copolymers including, poly(vinylpyrrolidone), polyquaternium-11, and polyquaternium-16, and are ultimately derived from petrochemicals. These polymers and copolymers are generally water and ethanol soluble and provide hold and film formation. Attention has turned to the use of naturally derived polymers that would offer more sustainable products; current alternatives are largely based on corn starch and modified corn starch, however, they exhibit major disadvantages including lack of ethanol solubility, opaque film formation and leave a starchy feel on the hair. The use of ethanol is highly desirable in hair styling compositions as its incorporation considerably decreases drying time after application to hair; 55% v/v ethanol is typical, although some aerosol formulations can be even higher.

A novel film-forming hair styling product was developed using alginic acid and pectin. These biopolymers comprise α-L-guluronic acid, β-D-mannuronic acid, and α-D-galacturonic acid moieties, and are readily available from food industry waste and seaweed. Although sodium salts of these biopolymers are good film-formers from aqueous solution, poor hydration in water-miscible solvents effectively limits the quantity of ethanol to a maximum of 20% before precipitation occurs. It was found that inclusion of an amine ameliorated this problem; the biopolymer and the amine containing moiety interact to form an amine salt of the biopolymer in situ. Alginic acid or pectin was added to water until a fine colloidal suspension was obtained, to which the amine was added, forming an amine alginate polymer that dissolved fully in water, providing a solution with high clarity. Ethanol was slowly added to this aqueous solution of amine alginate/pectinate until the requisite amount of ethanol had been added; it was observed that these compositions could tolerate ethanol as part of the solvent system up to 80%. Triethanolamine and 2-amino-2-methyl-1-propanol, typically found in cosmetic preparations, were excellent for use in these formulation In addition, amino acids, particularly histidine, proline, and glycine could also be successfully employed. The resultant compositions were applied to human hair and dried quickly and had stiff hold. The polymers were easily removed from the hair with shampoo.