Preparation And Properties Of Non-ionic Nitrogen-containing Etherification Starch Sizes

The main aim of the paper is that natural starch sizes were modified by chemical method in order to enhance its sizing properties and expand its application. Two kinds of non-ionic nitrogen-containing etherification starch sizes were prepared by using acrylonitrile and acrylamide as etherifying agent respectively. And the starch ethers with different degree of substitution were obtained by varying the feed ratio of etherifying agent to cornstarch. The effects of the modified starches on the behaviors of the films and adhesion to fibers were investigated. The experimental results demonstrate that starch etherification can improve the behaviors of starch films and adhesion to fibers. As the degree of substitution increases, the adhesion of cynaoethyl starch to pure cotton fiber substrates initially increases and then decreases. A maximal bonding strength can be achieved when cynaoethyl starch with degree of substitution is 0.047. However, the adhesions of the cynaoethyl starch to all polyester and polyester/cotton blend fiber substrates decrease as the degree of substitution increases when the degree of substitution exceeds 0.017. On the other hand the adhesion of carbamoyethyl starch to pure cotton, all polyester, and polyester/cotton blend fiber substrates increase as the degree of substitution increases. Both starch cynaoethylation and carbamoyethylation can improve the breaking strength, breaking elongation, flex resistance and wear loss of starch film.The effects of blending rate of cynaoethyl starch and carbamoyethyl starch with PVA1799 on the behaviors of the blending films and adhesion to fibers were also investigated. And the possibility of using these modified starches to substitute PVA component was evaluated by contrast experiments. The results of experiment show that both cynaoethyl starch and carbamoylethyl starch can enhance the proportion of replacing PVA as compared to the conventional size formulation used in modern sizing operation.