The influence of starch carbarnoylethylation upon the adhesion capability of starch to pure cotton, all polyester, and polyester/ cotton blend fiber substrates were investigated. The carbamoylethyl starch was prepared by the reaction of starch with acrylamide in an aqueous dispersion. The capability was evaluated in terms of the maximum strength and work-to-break of a roving impregnated with the starch pastes. The mechanical behaviors of the adhesive layers were estimated through a method by casting starch films and then by measuring their behaviors under controlled condition. It was found that the carbamoylethylation is an effective means for enhancing the adhesion of starch to fibers. No matter what type of the fibers is used, the adhesion capability obviously enhances compared with those of unmodified starch, even if the degree of substitution is at a very low level. The capacity increases steadily as the modification extent increases. Moreover, the experimental results are also discussed and analyzed especially through the failure type, internal stress, stress concentration, and mechanical behaviors of the adhesive layers among fibers. (c) 2007 Wile), Periodicals, Inc.