Patent ID: 7629000

Claim:
A method for preparing an antimicrobial polyester-containing article having chitosan covalently bonded thereon, comprising the sequential steps of: (a) providing a polyester-containing article; (b) contacting the polyester-containing article with a basic solution, thereby causing hydrolytic rupture of ester bonds in the polyester-containing articles to generate carboxylate groups; (c) optionally, washing the article produced in step (b); (d) contacting the article produced in step (b) or step (c) with a strong mineral acid solution, wherein the pH of acid solution is less than pH 2 and the mineral acid is HCl, H 2 SO 4 , or H 3 PO 4 , thereby acidifying the article by formation of free carboxylic acid end groups; (e) optionally, washing the article produced in step (d) with water; (f) contacting the article produced in step (d) or step (e) with a solution comprising a water-soluble, N,N′-disubstituted carbodiimide; (g) optionally, washing the article produced in step (f) with water (h) contacting the article produced in step (f) or step (g) with a solution comprising a chitosan agent selected from the group consisting of chitosan, chitosan salts, N-carboxyalkyl chitosan, and O-carboxyalkyl chitosan; and (i) optionally, heating-the article produced in step (h).