| 摘要 |
Starch ethers are obtained by reacting ungelatinized starch in the presence of water and an alkaline catalyst with an agent selected from the methyl and ethyl esters of crotonic and itaconic acids or the esters of acrylic acid. Specified esters are methyl acrylate, ethyl acrylate, butyl acrylate, methoxyethyl acrtlate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, benzyl acrylate, 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, tridecyl acrylate, 2-bromoethyl acrylate, allyl acrylate, ethyl crotonate and dimethyl itaconate. At least 10% of water must be present. The starch may be derived from corn, waxy maize, wheat, potato, or rice, and may be raw or partially oxidized or gelatinized provided that the birefrigence is retained. The reaction may be effected in a solution of sodium sulphate, sodium carbonate, or sodium chloride using sodium methoxide, sodium hydroxide, potassium hydroxide or barium hydroxide as catalyst. The product is useful as a size and as a binder for asbestos and clay. |
