50results about How to "Low degree of substitution" patented technology

A stretched cellulose acylate laminate film having a skin layer containing a cellulose acylate with a total degree of acyl substitution of more than 2.7 and a core layer containing a cellulose acylate with a total degree of acyl substitution of 2.0-2.7 wherein the core layer is thicker than the skin B layer and at least one of these layers contains a retardation-controlling agent, is excellent in high expressibility, little optical unevenness and good releasability from a support.

A reinforced wallboard core is prepared from a slurry comprising a mixture of β-calcium sulfate hemihydrate, a cellulose ether additive other than CMC and an amount of water that is sufficient to form a slurry and resulting in a wallboard density of less than 0.8 g/cc. The β-calcium sulfate hemihydrate is hydrated by the water forming a wallboard core reinforced by the cellulose ether additive. The cellulose ether, having a molecular weight of at least about 20,000 and a viscosity grade of at least about 100 cps, is selected to give the reinforced wallboard core improved nail pull resistance and greater flexural strength than unreinforced wallboard of the same density. The reinforced wallboard core may be used for reduced-paper wallboard and/or for lightweight wallboard, for example.

Process for the preparation of a starch ester, in particular a starch acetate, wherein a starch-based feedstock is reacted with an organic carboxylic acid anhydride in the presence of a catalyst. The reaction of the starch-based feedstock and the anhydride is performed at an excess pressure of about 0.1 to 50 bar in an essentially anhydrous medium containing 10% by weight of water at the most. As catalyst, sodium acetate, sodium hydroxide or sulphuric acid is used, and as the reaction medium, acetic acid or excess acetanhydride is used. By means of the invention, the duration of the esterification reaction can be significantly shortened, the separation of the product can be facilitated, and the recirculation of the waste solutions can be rendered more efficient.

The present invention relates to synthesis process of water soluble sulfoalkyl ether-beta-cyclodextrin. The process includes dissolving certain amount of beta-cyclodextrin in anhydrous dioxane solvent, adding certain amount of metal sodium for complete reaction, dropping certain amount of sulfo butyrolactone or sulfo propiolactone slowly into the reaction system, refluxing at certain temperature for etherification reaction, separating out amorphous solid after finishing the reaction, washing with methanol for several times, drying, dissolving the dried solid in deionized water, neutralization with acid to pH 8, desalting purification, concentrating the filtrate, and freeze drying to obtain white or yellowish water soluble sulfobutyl ether-beta-cyclodextrin or sulfopropyl ether-beta-cyclodextrin.

A rinse-off hair treatment composition for improved delivery of amino-acid to the hair and/or scalp comprising:(a) a particulate metal-amino acid complex;(b) at least one surfactant; and(c) a deposition aid.

The invention discloses an emulsified starch with high degree of substitution and a preparation method thereof. The preparation method of the invention comprises the following steps: firstly, adding starch into water for emulsifying, then preheating for 3-8 hours at the temperature of 50-80 DEG C, modifying with alkenyl succinic anhydrides, neutralizing, filtering, and washing the filter cake; then, degrading and filtering the obtained modified starch, regulating the pH value of the filtered solution to 7.0-8.0, and stirring for 10-60min; enabling the obtained product to flow into anion exchange resin for carrying out component separation, and eluting with 5-10% of neutral salt after separation; and finally, desalting the obtained eluent by a membrane filtration method, concentrating and drying to obtain the emulsified starch with high degree of substitution, wherein the degree of substitution is 0.02-0.1. The emulsified starch obtained by the preparation method of the invention has the characteristics of high degree of substitution, easy control, uniform substitution, good surface activity and the like, can be dissolved in cold water, and has wide application in the field of high added-value food chemical industry.

The invention discloses a production method for preparing low-substituted cellulose acetate, comprising the main steps of (1) pretreating raw materials; (2) esterifying; (3) hydrolyzing; (4), neutralizing; (5) precipitating filtrate; (6) washing and drying. By modifying existing cellulose acetate production technology and optimizing based on heterogeneous process, the method for preparing high-viscosity low-substituted cellulose acetate is implemented; the low-substituted cellulose acetate prepared by the method has well lyophilic, is soluble in dilute acid solution, acetone and water mixture, is good in degradability and biocompatibility, and may serve as a good drug coating material, a drug auxiliary material and a drug taste covering material to the field of medicine.

The invention provides a preparation method for sucrose fatty acid ester. The preparation method comprises the following steps: A) subjecting sucrose and alkyl stearate to a reflux reaction in a solvent mixture in the presence of potassium carbonate and potassium stearate so as to obtain a product mixture, wherein the solvent mixture is composed of dimethyl sulfoxide and dichloromethane in a volume ratio of 1: (3-8); B) adding a saturated sodium chloride solution into the product mixture, adjusting a pH value to 6.6 to 7.2, adding an extractant for extraction, carrying out liquid separation and taking an organic phase; and C) subjecting the organic phase to pressure-reduced concentration and carrying out drying by distillation so as to obtain sucrose fatty acid ester. The preparation method belongs to the technical field of chemical engineering, is simple in operation steps, optimizes a reaction system and reaction conditions, reduces the usage amount of dimethyl sulfoxide, decreases production of by-products, and improves product yield and purity; and the prepared sucrose fatty acid ester has low degree of substitution and excellent performance.

The invention provides a modified separator, a preparation method thereof and a lithium ion battery. The modified separator comprises a separator substrate and a polymer coating layer, wherein the polymer coating layer is arranged on a surface of the separator substrate and comprises a polymer, and a side link of the polymer is substituted by lithium sulfonate. The surface of the separator substrate in the modified separator comprises the polymer coating layer, the polymer coating layer comprises the lithium sulfonate group, the modified separator has a function of conducting lithium ions, themobility number of the lithium ions in an electrolyte can be increased when the modified separator is used in the lithium ion battery, the AC resistance value of the modified separator is reduced, the concentration polarization phenomenon is reduced, so that the growth of lithium dendrites of a battery negative electrode is reduced or prevented, the short-circuit risk of the battery is reduced, the safety and the rate performance of the lithium ion battery are effectively improved, and the cycle service lifetime of the lithium ion battery is prolonged. According to the preparation method of the modified separator, the polymer coating layer of which the side link is substituted by the lithium sulfonate is coated on the surface of the separator substrate, so that the modified separator hasrelatively low substitution degree in a polymer and also has relatively high lithium ion mobility, and the effect of reducing the lithium dendrites is achieved.

The invention discloses a fluorescent material. The fluorescent material with adjustable RGB values and/or adjustable color or even polysaccharide-based dynamic full-color fluorescent properties can be obtained by controlling the ratio of three-primary-color fluorescent modified polysaccharide and derivatives thereof and can gradually change in color under the excitation of ultraviolet light as the ultraviolet light excitation time is prolonged. Since in the fluorescent material, the substitution degree of fluorophores is low, the fluorescent material can maintain the excellent properties of polysaccharide and polysaccharide derivatives, such as mechanical properties, solubility properties and processing properties, and different types of fluorescent materials such as fluorescent coatings,fluorescent electrospun membranes, fluorescent fibers, fluorescent micelles and fluorescent ink can be processed very easily. The fluorescent ink has good film forming properties and can be printed on the surfaces of different base materials such as paper, plastic and metal. Therefore, the fluorescent material has very important practical value in the fields of safe printing, certificate counterfeiting and the like.

A liquid toner dispersion provided with marking particles comprising a pigment and a polyester based resin. The dispersion includes a nonpolar organic solvent and a hyperdispersant including a graft copolymer provided with an anchor group including an amine-functionalised polymer onto which at least one stabilising group is grafted. The stabilising group includes a hydroxylated fatty acid oligomer. The amine-functionalised polymer has a weight-average molecular weight of less than 1000 g/mol.

The invention relates to a preparation method of food-grade sodium carboxymethyl cellulose (CMC) (SG30) with high substitution degree and ultra-low viscosity, belonging to the technical field of sodium CMC production. The preparation method comprises the following steps of adding ethanol and liquid caustic soda with high concentration into a cellulose raw material, meanwhile, adding a viscosity reducer, reducing the viscosity of the cellulose raw material through primary viscosity reduction, and meanwhile alkalifying the cellulose raw material; then, adding an etherifying agent to etherify; and after the etherification reaction is ended, neutralizing, washing by using an ethanol solution with specific concentration according to a certain bath ratio (the cellulose raw material/the ethanol solution), removing the solution, drying and crushing to obtain the food-grade sodium CMC with ultra-low viscosity. The food-grade sodium CMC disclosed by the invention is relatively-high in substitution degree and ultra-low in viscosity and has the 2% Brookfield viscosity of 10-30CPS (measured by using a type-B viscometer), the substitution degree of larger than 1.20 and the purity of higher than 98%. The CMC is clear in solution and stable in viscosity. The food-grade sodium CMC is particularly suitable for being added into a refreshing beverage which is fine and smooth in taste.

The invention relates to a new hyaluronan derivative according to the general formula (I), the method of preparation thereof, a hydrogel based on the new derivative, method of preparation of the hydrogel and the use of the hydrogel in tissue engineering, cosmetics, medicine or regenerative medicine, especially in the form of scaffolds for the treatment of articular cartilage or bone tissue defects.

The invention discloses a method for preparing a corrugated-paper adhesive by using irradiation-microwave to esterify potato starch. The method comprises the following steps of: adding distilled waterinto the potato starch esterified by irradiation-microwave, adding modified nanocrystalline cellulose while stirring, then adding an oxidizing agent, after stirring and reacting in water bathing, adding aqueous sodium thiosulfate solution to end reaction, adding anhydrous sodium sulfate and a crosslinking agent, continuously carrying out constant-temperature water bathing, washing and filtering by using the distilled water in a vacuum pump, drying in a drying box, and grinding to the corrugated-paper adhesive. The method disclosed by the invention has the beneficial effects that 3-methacryloxypropyl trimethoxysilane is used as a surface treating agent of nanocrystalline cellulose particles, the modified nanocrystalline cellulose is used as reinforcing filler and is good in dispersion in starch matrix, so that the property of the adhesive can be obviously improved.

The invention relates to a medical hydrophilic fiber dressing. Specifically, the invention discloses a cellulose fiber carboxymethylation treatment liquid which can effectively improve the performanceof the obtained sodium carboxymethyl cellulose fiber by adding a specific assistant to the treatment liquid, thereby facilitating preparation of dressing with excellent strength and liquid absorption.

The invention relates to a preparation method of acetylated sodium hyaluronate, which belongs to the field of organic chemical synthesis, and is characterized by comprising the following steps of: under the protection of inert gas, adding a catalyst into hyaluronate and acetic anhydride in an organic solvent to catalyze a reaction, adding a water absorbent in the reaction process, and carrying out post-treatment, separation, purification and drying on the reaction liquid to obtain the product. According to the method, the condition that the substitution degree is too high or too low can be effectively avoided, so that a product with the acetyl substitution degree of 2.7-3.2 is obtained, reaction raw materials and conditions are mild, and separation and purification steps are simple.

The invention discloses a preparing process of high-substitution-degree carboxymethyl modified starch through a dissolving and gelatinating method. The process includes the steps that starch is heated in a solvent water solution until the temperature is higher than gelatinization point to carry out gelatinization or semi-gelatinization activating treatment on starch particles; a solvent method of the semi-gelatinated starch is used for carboxymethylation. The process of starch semi-gelatinization mainly includes the operation steps of primary emulsion blending, heating semi-gelatinization, middle washing, drying and smashing, and the carboxymethylation process mainly includes the operation steps of secondary emulsion blending, starch alkalization, chloroacetic acid etherification and follow-up treatment. The preparing process has the main creative advantages that starch gelatination activating method and the solvent method are combined to achieve semi-gelatinization of the starch particles. The characteristics of original starch are retained, chemical reactivity of the starch is improved, reaction efficiency and product substitution degree of solvent method carboxymethylation are improved, and product performance is improved.

The invention belongs to the pharmaceutical field, which relates to sodium carboxy methyl starch and a preparation method thereof. Products prepared by the existing preparation method of the sodium carboxy methyl starch are poor in clarification, have a plurality of white blocks, are extremely low in degree of substitution and are not in accordance with pharmaceutical standards; the technical problem solved by the invention is the improvement to the existing method, and the obtained products are colorless, transparent, uniform, exquisite and are in accordance with the pharmaceutical standards. The preparation method comprises the following steps: A. starch is hydrolyzed and gelatinized in a water solution with alcohol; B. carboxymethylation is carried out; and C pulpous products are settled, still stood overnight, filtered, alcohol precipitated, disssolved repeatedly, settled so as to obtain the sodium carboxy methyl starch; and the improvement lies in that a method of gradient heating is adopted to heat room temperature to 85 DEG C for carring out heating during the hydrolysis and gelatinization in the step A. The sodium carboxy methyl starch prepared by the preparation method is completely in accordance with requirements of the sodium carboxy methyl starch in ministry standards, which can satisfy the demands of the sodium carboxy methyl starch to be applied as immunity regulation medicines and is used for treating diseases, such as child repetitive respiratory infections and the induced bronchial asthma and the llike.

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 invention discloses sodium carboxymethylcellulose containing pentose structure unit and relates to sodium carboxymethylcellulose having excellent spinning, printing and dyeing performance which includes color yield and hand feeling. With equal and even slightly lower degree of substitution, the sodium carboxymethylcellulose has better paste printing and dyeing performance than high-DS CMC. An adopted method includes: selecting polysaccharides with the pentose structure unit exceeding 8% for carboxymethylation of cellulose. A carboxymethylated product of the pentose structure unit is carboxymethylcellulose of an Arabian polysaccharide carboxymethylated product or an xylan carboxymethylated product; when the sodium carboxymethylcellulose is used as printing paste of active pigment, color yield is high, and fabric is soft in hand feeling.

The invention relates to application of a solid acid catalyst in acetylation reaction of cellulose acetate. The solid acid catalyst comprises solid acid and a modified group, the modifying group at least has a C1-C20 carbon chain, and the contact angle of the solid acid catalyst to water is 120 degree lt; theta < lt >; by adopting the scheme of the invention, the problems of low cellulose acetylation conversion rate and low reaction yield caused by poor interface bonding force of solid acid and cellulose in the prior art are solved.

The invention provides a method for preparing (5-oxo-D-Proline)-leuprolide acetate. The method comprises the following steps: (1) solid phase peptide connection: preparing a raw material, connecting adipeptide, connecting a tripeptide, connecting a tetrapeptide, connecting a pentapeptide, connecting a hexapeptide, connecting a heptapeptide, connecting an octapeptide and connecting a nonapeptide to obtain leuprolide nonapeptide resin, wherein the steps of connecting the dipeptide to connecting the nonapeptide comprise protecting group removal; and then washing, neutralizing, washing again, connecting peptides and detecting free ammonia; (2) aminolysis: dissociating a crude product from the leuprolide nonapeptide resin through ethylamine; (3) HPLC purification: purifying by an HPLC preparation column to obtain leuprolide acetate intermediate purified product; (4) concentrating; and (5) filtering and freeze-drying.