Compositions are disclosed for dewatering mixtures of petroleum and water. The compositions comprise one or more of the following: an unreacted polysaccharide component; and one or both of a polysaccharide component reacted with a hydrophilic component and a polysaccharide component reacted with a hydrophobic component. The compositions may also include viscosifying agents or stabilizers to stabilize the compositions against separation, for example, prior to use. In particularly preferred embodiments the invention is drawn to compositions for breaking an emulsion; such compositions comprising a carbohydrate component containing a cationic starch joined to a hydrophobic moiety, providing the carbohydrate component oil solubility. The composition may optionally comprise one or more additional demulsifier selected from, without limitation, salts (such as a polyaluminum chloride, an aluminum chlorohydrate, an alum, etc.), metal salts (such as iron and zinc salts), dithiocarbamate, tannin, and organic demulsifiers such as poly-DADMAC and similar compounds.

Compositions and methods related to powdered hemostats that crosslink during and/or after application to a bleeding site are generally described.

The present invention concerns a method for modifying a polysaccharide material, preferably an amylaceous material, involving a first step of homogeneous solubilisation of said polysaccharide material in an aqueous solvent, followed by a step of homogeneous chemical functionalisation comprising at least one non-crosslinking chemical modification, or at least one crosslinking chemical modification, or a sequence of at least one non-crosslinking chemical modification and at least one crosslinking chemical modification. Secondly, the present invention concerns a modified polysaccharide material, in particular obtained by the method according to the invention, characterised in that it has a novel distribution of the chemical substituents attached to the hydroxyl functions of the anhydroglucose units of said polysaccharide material. The novel starches can be used as organic adjuvants for dry mortars made from cement or made from gypsum, in particular as a binder for a dry mortar made from cement or as a thickening agent for a mortar made from plaster.

The present invention concerns a method for modifying a polysaccharide material, preferably an amylaceous material, involving a first step of homogeneous solubilisation of said polysaccharide material in an aqueous solvent, followed by a step of homogeneous chemical functionalisation comprising at least one non-crosslinking chemical modification, or at least one crosslinking chemical modification, or a sequence of at least one non-crosslinking chemical modification and at least one crosslinking chemical modification. Secondly, the present invention concerns a modified polysaccharide material, in particular obtained by the method according to the invention, characterised in that it has a novel distribution of the chemical substituents attached to the hydroxyl functions of the anhydroglucose units of said polysaccharide material. The novel starches can be used as organic adjuvants for dry mortars made from cement or made from gypsum, in particular as a binder for a dry mortar made from cement or as a thickening agent for a mortar made from plaster.

The present document describes a process for the preparation of a low functionalization polysaccharide having carboxyl groups, comprising a) swelling of a polysaccharide granule in boiling water or a water/polyol mixture, to obtain a swollen polysaccharide; b) partial gelatinization of said swollen polysaccharide in an alkaline solvent mixture of water and alcohol and/or polyol, to obtain a partially gelatinized polysaccharide; and c) partial functionalization of said partially gelatinized polysaccharide with a functionalizing agent, to obtain the low functionalization polysaccharide.

The present document describes a process for the preparation of a low functionalization polysaccharide having carboxyl groups, comprising a) swelling of a polysaccharide granule in boiling water or a water/polyol mixture, to obtain a swollen polysaccharide; b) partial gelatinization of said swollen polysaccharide in an alkaline solvent mixture of water and alcohol and/or polyol, to obtain a partially gelatinized polysaccharide; and c) partial functionalization of said partially gelatinized polysaccharide with a functionalizing agent, to obtain the low functionalization polysaccharide.

A method for the synthesis of alkyl ω-carboxy(hydroxyethyl) polysaccharides is described. The method includes methylating or ethylating a polysaccharide or providing a methylated or ethylated polysaccharide, hydroxyethylating the methylated or ethylated polysaccharide, and oxidizing the hydroxyethylated polysaccharide to form the ω-carboxy(hydroxyethyl) polysaccharide. A method for the synthesis of oxidized polysaccharides is also described. The method includes hydroxypropylating a polysaccharide and oxidizing the hydroxypropylated polysaccharides. A method for the production of a solid capable of forming a hydrogel is also described. The method includes combining a first solution comprising an oxidized oligo(hydroxypropyl) polysaccharide bearing one or more ketone groups with a second solution comprising an amine substituted polysaccharide to form a third solution, and removing solvent from the third solution to form the solid, or adding an additional solvent to the third solution to precipitate the solid. Novel polysaccharides and hydrogels prepared according to these methods are also described.

A method for the synthesis of alkyl ω-carboxy(hydroxyethyl) polysaccharides is described. The method includes methylating or ethylating a polysaccharide or providing a methylated or ethylated polysaccharide, hydroxyethylating the methylated or ethylated polysaccharide, and oxidizing the hydroxyethylated polysaccharide to form the ω-carboxy(hydroxyethyl) polysaccharide. A method for the synthesis of oxidized polysaccharides is also described. The method includes hydroxypropylating a polysaccharide and oxidizing the hydroxypropylated polysaccharides. A method for the production of a solid capable of forming a hydrogel is also described. The method includes combining a first solution comprising an oxidized oligo(hydroxypropyl) polysaccharide bearing one or more ketone groups with a second solution comprising an amine substituted polysaccharide to form a third solution, and removing solvent from the third solution to form the solid, or adding an additional solvent to the third solution to precipitate the solid. Novel polysaccharides and hydrogels prepared according to these methods are also described.

Disclosed are a M-cell targeting and pH-responsive starch-based carrier material, and a preparation method and application thereof. The starch-based carrier material has a molecular structure as follows, a molecular weight of 7.04×10.sup.4 to 2.11×10.sup.6 g/mol, a degree of substitution of carboxymethyl groups of 0.04 to 0.28, and a grafting amount of targeting peptide GRGDS of 0.01% to 1.12% (calculated based on the content of N). The material is not dissolved in water when protonated at pH (pH=1.2) of the stomach, and is slowly dissolved in water when deprotonated at pH (pH=6.8) of the small intestine, therefore it has good responsiveness to pH of the gastrointestinal tract. The material can efficiently encapsulate a positively charged active substance by means of electrostatic interaction, therefore it can protect the active substances from being destroyed and inactivated in the gastrointestinal tract. Meanwhile, the material can target M cells to improve the transport efficiency of the active substance by M cells, thereby improving the bioavailability of the active substance.

A method for the synthesis of alkyl ω-carboxy(hydroxyethyl) polysaccharides is described. The method includes methylating or ethylating a polysaccharide or providing a methylated or ethylated polysaccharide, hydroxyethylating the methylated or ethylated polysaccharide, and oxidizing the hydroxyethylated polysaccharide to form the ω-carboxy(hydroxyethyl) polysaccharide. A method for the synthesis of oxidized polysaccharides is also described. The method includes hydroxypropylating a polysaccharide and oxidizing the hydroxypropylated polysaccharides. A method for the production of a solid capable of forming a hydrogel is also described. The method includes combining a first solution comprising an oxidized oligo(hydroxypropyl) polysaccharide bearing one or more ketone groups with a second solution comprising an amine substituted polysaccharide to form a third solution, and removing solvent from the third solution to form the solid, or adding an additional solvent to the third solution to precipitate the solid. Novel polysaccharides and hydrogels prepared according to these methods are also described.