23-12-1963 дата публикации
Номер: GB945207A
Автор:
A mixture of starch raw material and starch swelling agent is worked in a confining chamber at 125 DEG C. to 250 DEG C. for 0.5 to 5 minutes at a pressure substantially above the autogenous vapour pressure of the mixture at the reaction temperature to form a hot fluid homogenised mass, and immediately thereafter transferred into a region of substantially lower temperature and pressure. The proportion of starch swelling agent is 22% to 67% by weight of starch raw material dry substance, and the working is sufficient to provide an adiabatic temperature rise of at least 50 DEG C. in the worked mass. In a further embodiment, 0.01% to 50% by weight of starch dry substance, of a starch modifying agent may be present in the mixture. The starch raw material may be any native starch, a dextrin or thin-boiling starch, or a starch derivative such as starch acetate and propionate and starch ethers e.g. hydroxyethyl, carboxymethyl and cyanoethyl starch. The starch swelling agent or plasticizer is preferably water, but may be e.g. formamide, ethylene diamine dimethyl sulphoxide, pyrrolidine, urea, piperazine, glycerol, ethylene glycol, sorbitol, propylene glycol, chloral hydrate, dimethyl formamide and mixtures or solutions thereof. The starch modifying agent may be a hydrolytic or oxidising agent e.g. hydrochloric, sulphuric phosphoric, acetic, oxalic, benzoic, and levulinic acids; sodium and calcium hypochlorite, potassium permanganate, potassium persulphate, sodium perborate, hydrogen peroxide, benzoyl peroxide and hypochlorous acid; or may be a starch-derivatizing reagent such as anhydrides of acetic, n-butyric, succinic, isatoic, quinolinic and phthalic acids; n-butyryl chloride, benzene sulphonyl chloride, phosphorus oxychloride, beta-propiolactone, phenylisocyanate, vinyl acetate, vinyl n-butyrate, ketene, monochloroacetic acid, alpha-bromopropionic acid, ethylene chlorohydrin, propylene chlorohydrin, glyceryl alpha-chlorohydrin, ethylene oxide, propylene oxide, 3- ...
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