Abstract: Novel starch ether derivatives are prepared by reacting starch with 3-chloro-2-sulfopropionic acid. The resulting 2-sulfo-2-carboxyethyl starch ether derivatives find use in many applications, but are particularly useful as pigment retention aids in papermaking processes.

Abstract: A granular starch base is reacted with a selected propiolate ester in aqueous medium to produce a granular, acetal cross-linked starch, the cross-linkages of which are substantially removable in acidic medium. The cross-linked starch product thus prepared is useful in producing highly-substituted granular starch derivatives from which the cross-linkages may be readily and substantially removed as desired.

Abstract: Aqueous slurries or dispersions of starch are reacted with selected N-alkylimidazole-N'-sulfonates under specific reaction conditions to yield starch sulfate esters. The organic by-products produced in the reaction are readily removed by washing or dialysis.

Abstract: Aqueous slurries or dispersions of starch are reacted with ammonium fluorosulfate or an alkali metal fluorosulfate to yield starch sulfate esters. The inorganic by-products produced in the reaction are readily removed by washing or dialysis. These starch products may also be prepared in non-aqueous solvents or by a dry reaction process.

Abstract: A reagent for the modification of starch is prepared from the reaction of a 2,3-dihalopropionamide with a secondary amine. When starch is treated with this modifying reagent, a novel cationic starch characterized by the presence of a carboxamide group bound directly to a cationic amine substituent is produced.

Abstract: Highly substituted granular starches are prepared by reacting the starch in an aqueous system with a reagent capable of producing an acetal cross-linkage; reacting the resultant acetal cross-linked starch with a mono-functional esterifying or etherifying reagent under aqueous alkaline conditions and removing the acetal cross-linkages by treating under acid conditions. The highly substituted starches are particularly useful in operations, such as papermaking, wherein the cross-linkages can be removed and the starch readily dispersed during a relatively low pH starch cooking process.

Abstract: Aqueous slurries or dispersions of starch are reacted with N,N'-disubstituted imidazolium salts under controlled conditions to yield starch esters. The starch ester derivatives can also be prepared by a reaction in non-aqueous solvents.

Abstract: A reagent useful for the chemical modification of starch is prepared by the reaction of a 2,3-dihalopropionic acid or alkyl ester thereof with a secondry amine. The reaction of the reagent with starch, carried out in an aqueous solution under controlled conditions, produces novel amino acid ether derivatives which are characterized by the presence of both a cationic and an anionic substituent group on the same reactive site. The resulting starch ethers are characterized by their stability, their ability to form cooked pastes which are more resistant to gelling upon cooling and their lowered gelatinization temperatues.

Abstract: Retort starches comprising blends in specified proportions of starch and high amylose starch, said starches being hydroxypropylated and inhibited to a specified degree. These retort starches exhibit good thin-thick properties and high end viscosities and are especially suited for use in foods such as gravies and puddings.

Abstract: Modified starch products are prepared by reacting a starch, in an aqueous slurry or dispersion, with a salt of the reaction product of a 2-alkyl-2-oxazoline and phosphorus oxychloride, under controlled conditions.

Abstract: Retort starches comprising blends in specified proportions of starch and high amylose starch, said starches being hydroxypropylated and inhibited to a specified degree. These retort starches exhibit good thin-thick properties and high end viscosities and are especially suited for use in foods such as gravies and puddings.

Abstract: Aqueous slurries or dispersions of starch are reacted with imadazolides of carboxylic or sulfonic acids to yield starch ester derivatives. These starch products can also be prepared in non-aqueous solvents or by a dry reaction process.