US 12,084,570 B2
Chitosan as an intumescing, thermoformable flame retardant
Douglas Fox, Reston, VA (US); Mauro Zammarano, Gaithersburg, MD (US); and Whirang Cho, Gaithersburg, MD (US)
Assigned to AMERICAN UNIVERSITY, Washington, DC (US)
Filed by AMERICAN UNIVERSITY, Washington, DC (US)
Filed on Sep. 10, 2020, as Appl. No. 17/016,855.
Claims priority of provisional application 62/898,773, filed on Sep. 11, 2019.
Prior Publication US 2021/0095102 A1, Apr. 1, 2021
Int. Cl. C08L 5/08 (2006.01); C08B 37/08 (2006.01); C08K 3/22 (2006.01); C08K 3/26 (2006.01); C08K 5/00 (2006.01); C08K 5/07 (2006.01); C08K 5/092 (2006.01); C08K 5/3492 (2006.01); C08K 5/42 (2006.01); C08K 5/5353 (2006.01)
CPC C08L 5/08 (2013.01) [C08B 37/003 (2013.01); C08K 2003/2224 (2013.01); C08K 2003/2227 (2013.01); C08K 2003/265 (2013.01); C08K 5/0025 (2013.01); C08K 5/07 (2013.01); C08K 5/092 (2013.01); C08K 5/34926 (2013.01); C08K 5/42 (2013.01); C08K 5/5353 (2013.01); C08L 2201/02 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A flame retardant composition prepared by dissolution of chitosan or a modified chitosan by an aqueous acid over a period of up to 30 days followed by evaporation of the water, wherein the aqueous acid is selected from the group consisting of hypophosphorous acid, aminophosphonic acid, phosphonoacetic acid, phenylphosphonic acid, phenylphosphinic acid, and combinations thereof.