62results about How to "High degree of deacetylation" patented technology

The invention discloses an absorbable operating suture line and a preparation method thereof, and mainly relates to a chitosan operating suture line. The preparation process comprises the following steps of: preparing a chitosan spinning solution, spinning, solidifying, performing subsequent treatment, and the like. By the process, chitosan is subjected to wet spinning, so that the roundness of the cross section of the chitosan operating suture line is increased, and the operability of the suture line is improved; and the suture line prepared by the process has high tensile strength and elasticity and meets the clinical requirement.

The invention provides an O-2`-Hydroxypropyltrimethyl ammonium chloride chitosan preparation method, which comprises the following steps: firstly, Beta-Chitin is reacted with modifying agent to synthesize O-2`-Hydroxypropyltrimethyl ammonium chloride Chitin; secondly, acetyl of C2 digit on O-2`-HTACCt sugar ring is divested through reaction to obtain O-2`-HTACCts. Quaternary ammonium salt derivatives displacement reaction positioning in the invention occurs on hydroxyl of Beta-Chitin sugar ring, Chitin and chitosan quaternary ammonium salt derivatives of the hydroxyl positioning displacement are obtained, thus the method is simple and reliable. The degree of substitution (DS) of the intermediate product O-2`-HTACCt is more easily adjusted. The deacetylating reaction conditions are mild, the chitosan trunk chain degradation reaction degree is reduced, therefore O-2`-HTACCts with the high deacetylation degree (DD) and the high degree of substitution (DS) are obtained.

The invention discloses a method for making crust element which comprises the following steps that: a crab shell which is cleaned and soaked for the first time is put into a sodium hydrate solution for heat preservation; the crab shell which is washed by tap water to the neutral is soaked for the second time, the acid liquor is scoured off by the tap water; the curst element soaked by hydrochloric acid is put into the sodium hydrate solution for heat preservation and then is fished out as well as is washed by the tap water to the neutral, and the crust element is obtained. The method for making chitosan by the crust element comprises the following steps that: the crust element is put into the sodium hydrate solution and is sealed, after temperature preservation and the reaction, the mixture is soaked by the tap water and is washed by the tap water; the processed chitosan is taken out to be dried and put into the sodium hydrate solution as well as be sealed while preserving the temperature, after the reaction, the chitosan is taken out and is soaked in the tap water as well as is taken out and dried, thereby obtaining the chitosan. By processing by the method, the reaction speed is increased by 30 times, the alkali liquor dosage is reduced by 50 percent; the made crust element has white color, the crust element is washed by water and soaked to produce the chitosan, the molecular weight is great, the deacetylation is more than or equal to 95 percent, and the viscosity coefficient is more than or equal to 2000MPa.S.

The present invention provides a absorptive medical chitosan suture and its production process. The chitosan material is produced into the absorptive medical chitosan suture through a wet spinning process including the steps of compounding the chitosan into spun slurry in certain concentration, filtering, defoaming, metering, solidification, stretching, washing, oiling, twisting and sterilizing. The production process uses safe and cheap solvent system comprising acetic acid and acetate with pH greater than 3, and the chitosan slurry has high viscosity, high deacetylation degree and high stability. The absorptive medical chitosan suture has high tension strength and can meet the requirement of clinical use.

The invention provides a new preparation method of housefly larva chitosan, which comprises the following steps: 1) performing brine housefly larvae pretreatment to remove impurities; 2) stirring and soaking housefly larva shells with a hydrochloric acid solution, washing; 3) soaking the housefly larva shells washed in step 2) with a sodium hydroxide solution to remove wastes; 4) decoloring the housefly larva shells obtained in step 3) to obtain crude housefly larva chitin; 5) performing deacetylation of the crude housefly larva chitin by a microwave heating method to obtain chitosan. Chitosan is extracted from housefly larva shells by the method of the invention, and the method has the following advantages: 1) the deacetylation degree of the chitosan is increased to 94.4%; when compared with related national standards, the chitosan has a high deacetylation degree, and the product quality is improved by one grade; 2) the recovery rate of the chitosan is increased; 3) the deacetylationprocess is short in time, and low in energy consumption.

The invention discloses a preparation method of chitosan. The preparation method comprises the following steps of: chitin raw material crushing, ultrasonic pretreatment and eacetylation carried out by using an alkaline solution heating method. Compared with the chitosan prepared by the prior art, the chitosan prepared by using the process disclosed by the invention is high in deacetylation degree, low in alkaline solution concentration, low in equipment corrosivity, short in reaction time, reduced in production cost, environment-friendly, energy-saving, stable in process and suitable for large-scale industrial production.

The invention discloses a preparation technology of fly maggot chitin and chitosan and an application of fly maggot chitin to inducing a trichoderma aureoviride T2 bacterial strain to generate chitinase, belonging to the field of biological technology. The preparation technology of fly maggot chitin has the main characteristics that the traditional hydrochloric acid calcium removal technology is changed into an EDTA (Ethylene Diamine Tetraacetic Acid) calcium removal technology, the environmental pollution caused by waste acid discharge can be reduced, the damage of concentrated acid on chitin molecular chains can be avoided, and the chitin product with the high quality is obtained; and according to the preparation technology of fly maggot chitin, the traditional technology of 4-hour high-temperature concentrated alkaline refluxing is changed into a sodium hydroxide-amyl alcohol reaction system, microwave heating treatment is carried out twice, the utilization rate of alkali liquid is increased, the reaction time is greatly shortened, the energy consumption is saved, and a white powdery chitosan product with the lower moisture content and the higher degree of deacetylation is obtained. The fly maggot chitin disclosed by the invention can be used as a carbon source for inducing the trichoderma aureoviride T2 bacterial strain to generate the chitinase and has obvious induction effect.

The invention discloses a method for preparing a high-viscosity chitosan quick hemostatic patch. The method comprises the following steps: preparing chitosan gel from high-viscosity chitosan having a deacetylation degree in the range from 80% to 90%, drying the chitosan gel and then immersing one single side of the chitosan gel into a mixed solution of chloroacetic acid and isopropanol for carboxymethylation, and then soaking the chitosan gel into a 30% glycerol solution for 30 minutes and then draining; and finally, carrying out a cross-linking reaction by using a calcium chloride solution so as to introduce calcium ions and thrombin, and then carrying out vacuum freeze-drying, thereby obtaining the high-viscosity chitosan quick hemostatic patch. Raw materials used for the process of the method are low in cost; the process is simple and convenient, and short in period; the obtained chitosan hemostatic patch is high in adhesiveness, and capable of quickly stopping bleeding of a wound under the promotion effect of the calcium ions and the thrombin.

The invention belongs to ocean chemical engineering technology and particularly relates to a method for preparing chitosan with an ultrahigh deacetylation degree under a low alkali concentration condition. The method comprises the following steps: with chitosan with deacetylation degree of 60-85% as raw material, carrying out high temperature and high pressure reaction under a low alkali concentration condition, washing the product to be neutral with deionized water after the reaction, filtering and drying to obtain chitosan with deacetylation degree higher than 95%. According to the method provided by the invention, the high temperature and high pressure reaction condition is beneficial for a deacetylation reaction to achieve continuous deacetylation on chitosan with medium and low deacetylation degree so as to prepare chitosan with ultrahigh deacetylation degree, and the application of the chitosan in fields such as medical treatment, food, chemical modification and the like is expanded.

The invention relates to the technical field of biological medicines, in particular to a preparation method of hemostatic powder. The preparation method comprises the following steps: uniformly mixing chitosan extracted from an antarctic krill shell with an antimicrobial medicine in a mass ratio of (2-4): 1, sterilizing at 120 DEG C, and packaging. The invention further provides components and contents of the hemostatic powder. The chitosan extracted from the antarctic krill shell as a raw material is used as a main component of the hemostatic powder; and compared with ordinary chitosan, the chitosan extracted from the antarctic krill shell has a better hemostatic effect because a chitosan source is small in pollution, chitosan quality is greatly optimized and a raw material with high degree of deacetylation can be extracted.

The invention relates to an antibacterial modified chitosan foaming agent and a preparation method thereof. The preparation method of the antibacterial modified chitosan foaming agent comprises the steps of preparing modified chitosan, extracting white tea, preparing a complex solution containing chitosan, preparing a corn protein complex solution and preparing an antibacterial modified chitosan foaming agent. The antibacterial modified chitosan foaming agent has antibacterial ability more than 99% on staphylococcus aureus, escherichia coli, streptococcus, candida albicans or pseudomonas aeruginosa and shows good bacteriostatic ability. The antibacterial modified chitosan foaming agent can be applied to treatment on bacterial vaginitis, colpomycosis and mixed vaginitis and can be widely applied.

The invention provides an antibacterial and mildew-proof paint. The antibacterial and mildew-proof paint comprises the following components in parts by weight: 400-500 parts of water, 3-5 parts of a dispersing agent, 1-3 parts of a wetting agent, 3-5 parts of a defoaming agent, 100-130 parts of titanium dioxide, 200-250 parts of acrylic emulsion, 10-20 parts of glycerinum, 5-8 parts of a preservative and 15-20 parts of an antibacterial agent, wherein the antibacterial agent is montmorillonite loaded with chitosan. The antibacterial and mildew-proof paint provided by the invention adopts the montmorillonite loaded with the chitosan, and has the advantages of safety, no toxicity and good biocompatibility.

The invention relates to the technical field of cling films, and particularly relates to a preparation method of a multi-layer composite cling film. The preparation method of the multi-layer compositecling film comprises the following steps: (1) dissolving chitosan in a 1% acetic acid solution to obtain a solution A; (2) dissolving food-grade gelatin in deionized water to obtain a solution B; (3)mixing A with B to obtain a solution C; (4) adding a water solution of a squid active peptide into the solution B to obtain a solution D; and (5) carrying out centrifugal degassing on the solution Cand the solution D, then uniformly coating an acrylic plate with the solution C, carrying out drying, uniformly coating the film formed with the solution C with the solution D, carrying out drying, then uniformly coating the film formed by the solution D with the solution C, carrying out drying to form a film, carrying out balancing at room temperature for a certain time, and then removing a filmto obtain the composite cling film. The composite cling film provided by the invention has the advantages of strong mechanical property, difficult breakage, long service life and low cost.

The invention relates to the technical field of preparation of chitosan, and discloses a new chitosan. The new chitosan includes the following raw materials: in parts by weight, 2-5 parts of shrimp shell powder, 120-150 parts of a 7% HCl solution, 120-150 parts of a 10% NaOH solution, 12-15 parts of a 95% ethanol solution, 12-15 parts of absolute ethanol and 60-100 parts of a 50% NaOH solution. According to a high-efficiency preparation method for production of the new chitosan, the shrimp shell powder is adopted, and a commonly-used one-off short-time high-temperature boiling method can be changed into a long-time medium-temperature intermittent immersion method according to the physical and chemical properties of lobster shells, so that the chitosan with high degree of deacetylation is obtained, and the quality indexes of food-grade chitosan are met; during the experiment, long-term treatment is performed at medium temperature by using strong acids and strong bases of low concentration, fracture of beta-1,4-glycosidic bonds in the chitosan is reduced, and high-viscosity chitosan can be obtained; and at the same time, decolorized ethanol is recovered through distillation, the concentrated base liquid for deacetylation is recovered and diluted for second deproteinization, and recycling is achieved, so that the production cost is reduced effectively.

The invention relates to chitosan with high deacetylation degree and high molecular weight and a preparation method thereof. The preparation method comprises the following steps: dissolving chitin ina strong alkali solution to obtain a chitin-strong alkali solution; then, increasing the strong alkali content in the chitin-strong alkali solution to 35 to 45wt% in a manner of supplementing a strongalkali solution under the condition that the temperature is 0 to 10 DEG C; wherein the strong base is KOH or NaOH, and the deacetylation reaction is specifically carried out in an oil bath heater ora microwave reactor; the deacetylation degree of the prepared chitosan is 80-95%, and the viscosity-average molecular weight of the prepared chitosan is 7.9 * 10 < 5 >-9.0 * 10 < 5 > g/mol. Accordingto the preparation method disclosed by the invention, deacetylation is carried out under homogeneous conditions, so that the concentration of strong base and the temperature of deacetylation reactionare reduced, the process is simple, the conditions are mild, and the molecular weight of chitosan is remarkably improved; the prepared chitosan is high in deacetylation degree and high in molecular weight and has a great application prospect.

The invention discloses a preparation technology of a fruit and vegetable fresh-keeping agent, and relates to the field of agricultural chemical medicaments. The preparation technology of the fruit and vegetable fresh-keeping agent comprises the following five technological processes of pretreating, pickling and decalcifying, extracting chitin, carrying out concentrated alkaline deacetylation, and acquiring chitosan. By the technological method, in the pretreatment process, the reaction can be carried out fully by strictly controlling the concentration of hydrochloric acid and soaking time; in the concentrated alkaline deacetylation process, the proper sodium hydroxide concentration is selected, so that the degree of deacetylation is improved greatly; the viscosity also increases obviously; meanwhile, the time for reaction is also shortened, and the reaction speed and the efficiency are high. According to the invention, from the point of view of environment protection and waste utilization, the shells of waste shrimps and crabs are utilized as raw materials to prepare an efficient, nontoxic and odor-free chitosan fruit and vegetable natural fresh-keeping agent, so that a great amount of raw material cost is reduced; meanwhile, the environment is protected; the fruit and vegetable fresh-keeping agent is harmless to a human body, has a good fresh-keeping effect, and is long in fresh-keeping time.

The invention discloses a preparation method of a high-adhesion aqueous deepening agent, and belongs to the technical field of textile auxiliary preparation. Glycidyl is grafted onto the amino group of chitosan under an acidic condition to obtain a cationic adsorbent, an obvious adhesion buffering effect is achieved, the friction coefficient between fabric fibers can be effectively reduced, and ahigh-adhesion anti-corrosion film layer is formed. The anionic surfactant sodium lignin sulfonate used in the preparation method has a relatively large spatial structure, a relatively large steric hindrance can be generated in the high-adhesion aqueous deepening agent, the water-based dispersion performance of a dye can be improved, the deposition density of inorganic particles can be improved inthe later stage of curing by an adhesion promoting auxiliary agent, and the adhesion of the deepening agent film layer can be improved; and by virtue of added fel bovis and wetting agent, the wettingdegree and liquidity of the dye can be improved, the surface tension of water can be improved, the water can be prevented from forming water beads, an essential oil can accelerate the volatilization of a solvent, the curing of the deepening agent can be accelerated, and the moisture absorption performance of the fabric can be improved.

The invention relates to a chitosan compound with a function of enhancing immunity. The chitosan compound comprises chitosan, Chinese wolfberry fruit extract, ganoderma lucidum extract and ginkgo leaf extract, wherein the weight ratio of the chitosan, Chinese wolfberry fruit extract, ganoderma lucidum extract and ginkgo leaf extract is 40-60:30-50:10-20:5-8. The chitosan compound has the advantages that the high-purity chitosan is prepared by a microwave method, and the high-purity chitosan is combined with the extracts of traditional Chinese medicine Chinese wolfberry fruit, ganoderma lucidum and ginkgo leaf to jointly increase body immunity, comprehensively adjust human body function balance in a bidirectional manner, mobilize body internal vitality and adjust the body metabolism function; the active components of the chitosan compound are allowed to enter five internal organs and tonify the whole body so as to achieve healthcare effects of strengthening and consolidating body resistance and strengthening physical health, and accordingly the body immunity is enhanced fundamentally.

The invention relates to a preparation method of low-molecular chitosan, which comprises the following steps: ultrasonically treating crab shells with diluted hydrochloric acid, adding deionized water to dilute the diluted hydrochloric acid, adding benzoic acid for continuous ultrasonic treatment, deproteinizing with low-concentration sodium hydroxide, washing, and thermally treating deacetylated wet chitosan with high-concentration sodium hydroxide, dissolving the wet chitosan in a diluted hydrochloric acid aqueous solution, adding into a three-electrode system which takes a graphite plate as an anode, foam titanium as a cathode and a silver/silver chloride electrode as a reference electrode, keeping a certain distance of 3-5cm between the anode and the cathode, keeping a constant point potential of-1.2 to-1.5 V, and electrolyzing for 0.5-1 hour. According to the method, the repeated deacetylation process of sodium hydroxide in the deacetylation process is simplified, the usage amount of sodium hydroxide is reduced, the deacetylation degree of the low-molecular chitosan prepared by combining one-step sodium hydroxide deacetylation with electrolysis is as high as 94.8%, the molecular weight is low and reaches about 2500, the molecular weight distribution is narrow, the molecular weight distribution coefficient is 1.13, and the content of protein impurities in the low-molecular chitosan is as low as 0.072%.

The present invention provides konjak and kapok fiber moisturizing wet tissue and a preparation method thereof; wherein low-temperature plasma pretreatment is conducted on kapok fibers, non-polymeric gas such as plasma of nitrogen and oxygen is used for conducting surface bombardment on the kapok fibers, etching is conducted on the surfaces of the kapok fibers to form pits, and the wax on the surface of the kapok fiber is effectively removed, so that the internal structure of the kapok fiber is opened, the space of the internal structure is enlarged, the surface area of the kapok fiber is increased, and konjac glucomannan can enter the kapok fiber to act and be fully combined; meanwhile, the internal structure of the kapok fiber is opened, so that groups hidden in the kapok fiber are exposed; not only are the adhesiveness and wettability of the kapok fiber improved, but also under the action of weak base, specific functional groups and a large number of carboxyl groups, hydroxyl groups and other groups in konjac glucomannan molecules form a polymer in modes of adsorption, chemical crosslinking, graft copolymerization and the like; therefore, the binding force between the kapok fiber and the konjac glucomannan is greatly enhanced.