Durable Water-Repellent Cotton Fabrics Prepared by Low-Degree Substitution of Long Chain Alkyl Groups

Three kinds of water-repellent cotton fabrics, A, B, and C-, are produced by alkylation with only 0.07 alkyl units per glucose unit. Sample A is prepared by alkylation by means of acetylation without mercerization, B is by direct alkylation after merceriza tion, and C is by alkylation by means of allylation and bromination. The merits of the methods are compared by contact angle measurements and spray tests after repeated laundry cycles. Sufficient water-repellency is attained with an alkyl length of over C 12 . These samples retain a fabric hand, water-vapor permeability, and biodegradability similar to those of untreated cellulose fabric. The end-use properties of alkylated fabrics before and after laundering are also tested.