799 results about "Acetylation" patented technology

The invention discloses a degradable bamboo fiber express packaging bag and a preparation method thereof, and belongs to the technical field of express packaging. The packaging bag is prepared from, by mass, 32-42 parts of pretreated bamboo fibers, 22-28 parts of poly (butylene succinate), 9-14 parts of modified nano calcium carbonate, 12-16 parts of polycaprolactone, 6-11 parts of acetylated chitosan and the like, and the key raw materials are all treated through an exclusive pretreatment or modification process. The preparation method comprises the steps of raw material plasma activation, segmented high-speed mixing, vacuum drying, precise-parameter twin-screw extrusion granulation, secondary drying, precise film blowing, high-precision heat-sealing bag making and the like, and the technological parameters of all the steps are clear. The product disclosed by the invention can be efficiently degraded in a natural environment, has excellent tensile resistance, puncture resistance and impact resistance, is stable and controllable in processing process, and is adaptive to actual requirements of express packaging and industrial batch production.

The invention provides a method for regulating and controlling the alcoholysis degree of polyvinyl alcohol, which comprises the following steps: carrying out acetylation reaction on a polyvinyl alcohol raw material and an acetylation reagent to obtain a polyvinyl alcohol product with the alcoholysis degree different from that of the polyvinyl alcohol raw material. According to the method for regulating and controlling the alcoholysis degree of polyvinyl alcohol provided by the invention, polyvinyl alcohol is taken as a raw material, acetyl is reversely inoculated through acetylation reaction, polyvinyl alcohol products with different alcoholysis degrees can be obtained, and the method is relatively high in stability, simple and suitable for large-scale production.

The invention discloses a biological catalytic synthesis method of norambrox ether, which comprises the following steps: step 1, starting from trans-nerolidol, carrying out carroll rearrangement reaction to synthesize farnesyl acetone; 2, in the presence of a cofactor, converting farnesyl acetone into high farnesol acetate under catalysis of Bayer-Villiger monooxygenase; step 3, catalyzing the deacetylation of the high-farnesol acetate by using esterase to obtain EE-high-farnesol; and step 4, carrying out enzymatic conversion on farnesol by using the squalene hopaene cyclase mutant to obtain norambrox ether. The transformation process is safe and non-toxic, Bayer-Villiger monooxygenase which is new with a key enzyme, natural co-expressed esterase, alcohol dehydrogenase and squalene and hopaene cyclase mutants matched with the system are used for synergistic transformation, so that not only is the coenzyme for oxidation reaction promoted to be recycled, but also the conversion efficiency is improved; conversion from farnesyl acetone to norambrox ether can be efficiently and specifically catalyzed, and a final product can be directly obtained from a reaction system without separation and purification of an intermediate.

The invention provides a polyarylester nanofiber and a preparation method thereof, and the preparation method comprises the following steps: firstly, carrying out acetylation reaction on 4-hydroxybenzoic acid (HBA) and 6-hydroxy-2-naphthoic acid (HNA) to obtain acetylated HBA and acetylated HNA, and then carrying out copolymerization on acetylated HBA and acetylated HNA and 4-hydroxybutyric acid (GHB) to obtain HBA / GSB / HNA copolymerized arylester granules B; the preparation method comprises the following steps: carrying out blending spinning on granules B and HBA / HNA copolymerized aromatic ester granules A obtained by copolymerizing acetylated HBA and acetylated HNA in the prior art, putting the obtained blended polyarylate fibers into an organic solvent containing a strong base, carrying out chemical etching and deprotonation, carrying out disassembly from top to bottom to obtain a polyarylate nanofiber suspension, and finally carrying out suction filtration and drying to obtain the polyarylate nanofibers. According to the preparation method disclosed by the invention, the blended polyarylester fiber containing an aliphatic chain is subjected to etching and deprotonation treatment through strong base to disassemble the polyarylester nanofiber, and a certain amount of-CH2-structure is introduced into a main chain, so that disassembly preparation of the nanofiber is facilitated, and the polyarylester nanofiber with uniform diameter and length and controllable length-diameter ratio is obtained.

The invention discloses an environment-friendly EVA (Ethylene Vinyl Acetate) material and belongs to the technical field of polymer composite materials. The environment-friendly EVA material is prepared from the following components: EVA resin, a bio-based dynamic cross-linking agent DBX-200, a natural fiber reinforced network, a hybrid flame-retardant filler, a bio-based plasticizer, zinc oxide, zinc stearate and an antioxidant. The bio-based dynamic cross-linking agent DBX-200 is introduced to replace a traditional toxic peroxide cross-linking system, pollution-free cross-linking is achieved, and the material is endowed with a self-repairing function. The natural fiber reinforced network is composed of silane coupling agent modified bamboo fibers and carboxylated nanocellulose, a multi-stage reinforced structure is formed, and the mechanical property is remarkably improved. The hybrid flame-retardant filler coats Mg (OH) 2 / HNTs through dopamine, so that synergistic flame retardance of a gas phase and a condensed phase is realized; the bio-based plasticizer is compounded by acetylated tributyl citrate and epoxidized cashew nut oil, and the plasticizing efficiency and the migration resistance are both considered. The material has the characteristics of high mechanical property, excellent flame retardance and environmental friendliness, and is suitable for the fields of shoemaking and the like.

The invention provides a full-degradable polymer composite material for tableware and a preparation method of the full-degradable polymer composite material, and belongs to the technical field of polymer materials. According to the invention, amylose corn starch, hydrophobic modified corn starch, cassava acetylated distarch phosphate, a polylactic acid-poly (butylene succinate) interpenetrating network structure material, a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate, polycaprolactone, stearic acid modified micron titanium dioxide, chitosan quaternary ammonium salt and a composite plasticizer are adopted according to a specific ratio; the fully-degradable polymer composite material is obtained by compounding the composite heat stabilizer and stearic acid, has controllable and good biodegradability and good mechanical properties, enhances heat stability, improves processability, makes all the components easier to mix uniformly, facilitates molding processing of the material, and improves production efficiency and product quality.

The invention discloses a sodium alginate embedded iron-carbon microcapsule material for repairing cadmium and arsenic polluted soil and a preparation method of the sodium alginate embedded iron-carbon microcapsule material, and belongs to the technical field of soil heavy metal pollution repairing materials. The material comprises straw biochar, high-iron steel slag powder, a sulfydryl acetylated chitosan-iron monatomic cluster compound, a boron-doped graphitized carbon coated cobalt ferrite nanosheet, sodium alginate, calcium chloride and sodium carbonate. Wherein the sulfydryl acetylated chitosan is prepared by reacting chitosan with sulfydryl acetic anhydride, dialyzing and drying, and performing solvothermal reaction with ferric nitrate under high pressure. The preparation method comprises the following steps: pyrolyzing and drying the straw biochar, reacting the high-iron steel slag with sulfuric acid, adding the biochar, adjusting the pH value, adding sodium carbonate, mixing to obtain an iron-carbon-based passivation material, mixing with two modified compounds, mixing with a sodium alginate solution, dropwise adding a calcium chloride solution, and stirring and curing. The material can be applied to remediation of cadmium and arsenic polluted soil.

The application discloses an acyltransferase mutant with high acetylation activity and application thereof, and belongs to the technical field of enzyme engineering. The acyltransferase mutant provided by the application contains one or more mutation sites in the 62th and 64th positions on the basis of the acyltransferase mutant with the amino acid sequence shown in SEQ ID NO. 1. The acyltransferase mutant obtained by the application has higher acyltransferase activity and catalytic efficiency than the original enzyme before mutation, and can improve the yield of N-acetyl-trans-4-hydroxyproline. Therefore, the acyltransferase mutant of the application has important significance in the efficient biosynthesis of N-acetyl-trans-4-hydroxyproline, and has wide application prospects in the fields of biological materials, medicines or cosmetics.

The present invention relates to a high-temperature starch-type wetting agent and a preparation method and application thereof, wherein the wetting agent comprises an active ingredient and water, wherein the mass ratio of the active ingredient to the water is (0.05-0.15): 1, and the active ingredient comprises the following raw materials in parts by weight: 45-65 parts of a starch-based film-forming agent, 5-10 parts of a plasticizer, 15-20 parts of a lubricant, 1-2.5 parts of an emulsifier, 4-6 parts of a coupling agent, 0.5-1.5 parts of a preservative, and 0.02-0.05 parts of a defoaming agent; wherein the plasticizer is cardanol acetate, tributyl citrate, and mannitol in a mass ratio of 1:1:(1.5-2); and the starch-based film-forming agent is at least one of acetylated distarch adipate, oxidized starch, and hydroxypropyl starch. The glass fiber yarn products produced with the wetting agent have significantly reduced scattered silk defects on the cloth surface, and the amount of powder falling during the weaving process is also greatly reduced, which meets the high standard requirements for the production of printed circuit boards.

The invention discloses a lignin-based epoxy anticorrosive paint and a preparation method thereof. The anticorrosive paint is prepared by mixing a lignin-based epoxy anticorrosive paint component, a lignin-based phenolic amine curing agent and a diluent. According to the lignin-based epoxy anticorrosive paint disclosed by the invention, on one hand, a lignin epoxy resin acetylation modification method based on lipase is introduced, and the content of hydrophilic groups is reduced, so that formation of a compact lignin cross-linked network structure is promoted, and the barrier ability, heat resistance and aging resistance of an anticorrosive coating on a chemical medium are improved on the resin level; on the other hand, lignin and furfural are respectively used for partially replacing phenol and paraformaldehyde to prepare a lignin-based phenolic aldehyde amine curing agent with high chemical inertness, so that the protection effect of a coating in an extreme corrosion environment and the adhesive force to a metal base material are improved on the curing agent level. The lignin-based epoxy anticorrosive paint prepared by the invention has good corrosion resistance, aging resistance, thixotropy and adhesive force.

The disclosure relates, in part, to the use of compositions of poly N-acetylated glucosamine (PNAG), deacetylated PNAG (dPNAG), and antibodies and antibody fragments specific to PNAG in the prevention and treatment of filariasis.

The invention discloses acyltransferase, a mutant and application in preparation of acetyl harpagide, the acyltransferase ancestor sequence capable of biologically catalyzing the acetylation of harpagide is firstly screened, then the acyltransferase is subjected to mutation modification, the enzyme activity is further improved, the harpagide is used as a substrate, and the acyltransferase and the mutant are synthesized into the acetyl harpagide. The ancestor acyltransferase and the mutant are used for acylation reaction, so that the application of the acyltransferase in the fields of medicines and the like is promoted, and certain help is provided for the aspect of drug acylation modification.

Provided is method for producing a glycoside in which a phenolic compound is bonded to an anomeric position of a sugar, the method including: a step (1) of reacting a peracetylated sugar with the phenolic compound in the presence of an acid catalyst; and a step (2) of directly adding a deacetylating agent and a deacetylating solvent selected from the group consisting of water and an alcohol to a reaction mixture obtained in the step (1) to perform a deacetylation reaction.

The invention discloses bioactive gel for accelerating wound healing. The gel is prepared from the following raw materials in percentage by weight: 0.8%-1% of bomer 980, 5%-5.5% of glycerol, 15%-20% of white vaseline, 51.7%-55% of phosphate buffer, 1.8%-2% of nano royal jelly acid, 2%-3% of recombinant III type human collagen, 0.4%-0.5% of sodium hyaluronate, 1%-3% of sodium alginate, 20%-25% of polyethylene glycol-400, 1.5%-3% of dopamine-methacrylamide copolymer, 0.5%-0.8% of nano silver and 0.3%-0.5% of phenoxyethanol. The nano royal jelly acid and the nano silver have a synergistic antibacterial effect, so that the inhibition effect on drug-resistant bacteria such as MRSA and pseudomonas aeruginosa is remarkably improved, and meanwhile, the wound epithelization can be accelerated and scar formation can be reduced through the dual effects of the recombinant III type collagen and the acetylated sodium hyaluronate. The defects that a traditional dressing is narrow in antibacterial spectrum, single in repairing effect, poor in environmental adaptability and the like are overcome, and the dressing is particularly suitable for complicated wounds such as diabetic foot ulcer and second-degree burn.

The invention relates to a preparation method of triethylene glycol diacetate, and belongs to the technical field of organic synthesis. The method comprises the following steps: adding triethylene glycol, an acetylation reagent and a multifunctional catalyst into a reaction kettle provided with a stirrer, a thermometer and a reflux condensing tube, and stirring and heating for reaction under the protection of nitrogen; after the reaction is finished, cooling reaction liquid to room temperature, and filtering and recovering the catalyst; performing reduced pressure distillation and silica gel column purification on the filtered reaction liquid to obtain triethylene glycol diacetate; the multifunctional catalyst is prepared from mesoporous silicon dioxide microspheres, 3-mercaptopropyltrimethoxysilane, 4-vinyl benzo-18-crown ether, sodium ethoxide, absolute ethyl alcohol, an ethanol solution of tetrabutyl titanate and chlorosulfonic acid. The preparation method comprises the following steps: preparing the mesoporous silicon dioxide microspheres, 3-mercaptopropyltrimethoxysilane, 4-vinyl benzo-18-crown ether, sodium ethoxide, absolute ethyl alcohol, the ethanol solution of tetrabutyl titanate and chlorosulfonic acid; the triethylene glycol diacetate prepared by the method has high yield and high purity, and can meet industrial production and market requirements.

The invention discloses a peracetylated polysaccharide derivative mixing accelerator as well as a preparation method and application thereof, and relates to the technical field of polysaccharide derivatives. Alkyl polyglucoside and glycidyl ether are subjected to etherification reaction to obtain polysaccharide derivatives; and adding acetic anhydride and an organic weak base catalyst into the polysaccharide derivative, and carrying out esterification reaction to obtain the peracetylated polysaccharide derivative. The obtained peracetylated polysaccharide derivative can be used for reducing the minimum miscible pressure of CO2 in an offshore oilfield. The polysaccharide derivative provided by the invention is simple in synthesis process, and the molecular activity of the polysaccharide derivative can be regulated and controlled by changing the number of carbon dioxide-philic groups and the length of oleophylic unsaturated hydrocarbon chains, so that the polysaccharide derivative can be used in the CO2 oil displacement process of oilfield exploitation, and the minimum miscible pressure in the CO2 oil displacement process is effectively reduced.

The invention discloses multifunctional nano-enzyme composite hydrogel as well as a preparation method and application thereof. The preparation method comprises the following steps: synthesizing molybdenum disulfide MoS2 by taking hexaammonium heptamolybdate tetrahydrate and thiourea as raw materials; the preparation method comprises the following steps: carrying out stirring reaction on MoS2 and cysteine to obtain MoS2-LC; the preparation method comprises the following steps: mixing galangin with MoS2-LC, carrying out ultrasonic treatment, and carrying out a stirring reaction to obtain MoS2-LC (at) Gal; the preparation method comprises the following steps: adding acetic anhydride into a carboxymethyl chitosan aqueous solution to obtain N-acetylated carboxymethyl chitosan N-CC; the preparation method comprises the following steps: adding 1-butyl-3-methylimidazole chlorine salt into N-CC to react, and carrying out alcohol precipitation to obtain N-CC-IL; a cross-linking agent, MoS2-LC (at) Gal and N-CC-IL are subjected to a blending reaction, and SNCI (at) MLG is obtained. Pharmacodynamic results show that the multifunctional nano-enzyme composite hydrogel prepared by the preparation method disclosed by the invention can play a role in inhibiting ferroptosis while having an antibacterial effect, and a new possibility is provided for periodontal local treatment.

The invention provides application of a deacetylase inhibitor or a derivative thereof and application of a pharmaceutical composition, and belongs to the technical field of biology. The application of the deacetylase inhibitor or the pharmaceutically acceptable derivative thereof comprises the application of the deacetylase inhibitor for preparing a medicine for treating osteoporosis; wherein the deacetylase inhibitor is used for inducing histone acetylation in a cell nucleus. By inducing acetylation of histone in a cell nucleus, the differentiation direction of the bone marrow mesenchymal stem cells is accurately and efficiently controlled, and a treatment scheme for osteoporosis related diseases is developed.

The invention belongs to the technical field of biomass materials and environment-friendly adhesives, and relates to a biomass adhesive, in particular to a preparation method of a biomass environment-friendly adhesive based on longan shells, which comprises the following steps: firstly, cleaning, drying, crushing and screening the longan shells for pretreatment, and then carrying out alkalization and acetylation chemical modification to obtain the biomass environment-friendly adhesive based on the longan shells. And finally, compounding with gelatinized starch, a chitosan acetic acid solution and citric acid, and adjusting the viscosity to obtain the adhesive. The waste longan shells are used as raw materials, agricultural waste recycling is achieved, the product is free of formaldehyde release and biodegradable, and the viscosity of the prepared adhesive is 1000-2000 mPa.s at the temperature of 25 DEG C and is measured through a rotary viscometer; the wood-wood bonding strength is larger than or equal to 2.5 MPa, the 24-hour water absorption rate is smaller than or equal to 25%, the problems that a traditional biomass adhesive is short in performance and low in cost, special equipment is not needed for preparation are solved, the adhesive is suitable for the industrial fields of artificial board manufacturing, furniture manufacturing and the like, and environment-friendly transformation of the adhesive industry is promoted.

The invention relates to the technical field of fibers, in particular to a controlled-release anti-aging polypropylene fiber and a preparation method thereof. The fiber is prepared from polypropylene homopolymer resin, a reaction type interface layer master batch and a controlled release anti-aging master batch, the reactive interface layer master batch is formed by reacting and extruding maleic anhydride modified polypropylene and 3-aminopropyl terminated polydimethylsiloxane, so that the interface compatibility is enhanced; the controlled-release anti-aging master batch contains hydroxyl and peracetylated cyclodextrin grafted siloxane carriers, and an ultraviolet absorbent, a light stabilizer and an antioxidant are included, so that the controlled release of an anti-aging agent is realized. The preparation method comprises the steps of master batch preparation, final mixing granulation, melt spinning and drafting setting. The fiber strength is remarkably improved, the boiling water shrinkage rate is reduced, the strength retention rate after ultraviolet aging reaches 93% or above, the yellow index change is small, and the outdoor service life is prolonged.

The invention belongs to the technical field of chemical pharmacy, and particularly relates to a preparation method and application of an impurity of a beta2 adrenal receptor stimulant and M receptor antagonist bifunctional active compound. According to the impurity preparation method of the beta2 adrenal receptor stimulant and M receptor antagonist bifunctional active compound, acetylation of amino is successfully realized by using acetylation reagents such as acetyl chloride and alkali accelerators such as N, N-diisopropylethylamine, then debenzylation is performed through hydrogenation reaction, and the compound shown in the formula I is successfully prepared. Then, through liquid chromatography purification, a high-purity compound as shown in the formula I is obtained, and the raw material medicine as shown in JKN2304 can meet the requirements of reference substances in the research and development process; the technical problem that in the prior art, an impurity synthesis process of a beta 2 adrenal gland receptor agonist and M receptor antagonist bifunctional active compound is lacked is solved.

The invention discloses a modified bamboo fiber reinforced polypropylene composite material and a preparation method thereof, and belongs to the field of polypropylene composite materials, the modified bamboo fiber reinforced polypropylene composite material is characterized by comprising the following raw materials by mass: 1-10 parts of modified bamboo fiber, 80-90 parts of polypropylene, and 1-5 parts of a compatilizer. The modified bamboo fiber is prepared by modifying the surface of bamboo fiber by using acetic anhydride as an acetylation reagent and concentrated sulfuric acid and glacial acetic acid as a solvent system. Through acetylation modification of the bamboo fiber, the surface hydrophobic effect of the bamboo fiber is greatly improved, the bamboo fiber adapts to a polypropylene polymer non-polar material, and the interfacial compatibility between the bamboo fiber and polypropylene is improved. Fine fibers can be separated from the modified bamboo fibers through two screw extrusion processes under the shearing action of the screws and are uniformly dispersed in a polypropylene matrix, the fine fibers have the effect of a heterogeneous nucleating agent on polypropylene, the reinforcing effect of the bamboo fibers on the polypropylene is improved, and the composite material is endowed with more excellent mechanical performance and thermal stability.

The disclosure provides methods for synthesis of peracetylgalactosamine-1-pentanoic acid, also called peracetylated D-galactosamine C5 linker or GalNAc C5 linker, using a vegetal source as a starting material, such as vegetal-sourced D-glucosamine or D-glucosamine hydrochloride. Also provided are methods for purifying the peracetylgalactosamine-1-pentanoic acid, or GalNAc C5 linker, thus produced so that the end product comprises fewer impurities.

Belongs to the technical field of pine wood nematode disease prevention and control, and particularly relates to a preparation method and application of a pyrazole-chitosan oligosaccharide derivative. Chloroacetyl chloride serves as an acylating agent, chitosan oligosaccharide is acetylated, and chloroacetyl chitosan oligosaccharide is generated; then, a pyrazole molecule with nematicidal activity is connected to the Cl site of the chloracetyl chitosan oligosaccharide through ammonolysis reaction, and the novel pyrazole-chitosan oligosaccharide derivative is obtained. The derivative has relatively high contact activity on pine wood nematodes, and LC50 of 24 hours and LC50 of 48 hours are 4.814 mM and 4.061 mM respectively; the chitosan oligosaccharide can remarkably inhibit multiple physiological indexes such as movement, feeding and service life of the pine wood nematodes, and is good in stability, low in molecular weight of the chitosan oligosaccharide, good in water solubility, green and environment-friendly, and the plant toxicity is remarkably reduced. The derivative has a good application prospect in the aspect of controlling the pine wood nematode disease and can be applied to prevention and control of the pine wood nematode disease.

The present invention provides a paroxysmal hemoglobinuria indication drug ipropam key intermediate synthesis method, and relates to the technical field of ipropam, the method comprises: taking p-bromobenzaldehyde as an initial raw material, adopting an S-configuration catalyst to obtain an intermediate 03, carrying out protection group removal on the intermediate 03, carrying out automatic ring closing to obtain an intermediate 04, and carrying out post-treatment to obtain the paroxysmal hemoglobinuria indication drug ipropam key intermediate. Reducing the intermediate 04 with sodium borohydride to obtain a single cis-configuration intermediate 05, then carrying out a chiral flip reaction and hydrolysis to remove p-nitrobenzoic acid, then carrying out an etherification reaction with diethyl sulfate to obtain an intermediate 08, reducing amide of the intermediate 08 with sodium borohydride and boron trifluoride diethyl etherate to obtain an intermediate 09, then carrying out an acetylation reaction to protect amino, and finally carrying out a reaction to obtain the chiral cis-configuration intermediate 03. Cuprous cyanide is subjected to a cyanation reaction and a hydrolytic esterification reaction to obtain the ipropam key intermediate TM. The method is low in raw material price, high in chiral control selectivity, easy in reaction condition control and low in equipment requirement, avoids column chromatography and other operations, and is more suitable for industrial production.

The invention discloses a synthesis method of helicid, and relates to the technical field of compound synthesis, glucose is taken as an initial raw material, allose is obtained through a series of reactions, pentaacetyl allose is prepared from allose through acetylation reaction, tetraacetyl alloside is prepared through selective deacetylation reaction, substitution reaction and nucleophilic substitution reaction, and the helicid is synthesized through a one-step method. And finally, carrying out a deacetylation reaction on the tetraacetyl alloside to prepare helicid. Helicid has the effects of calming, sleeping, easing pain and resisting inflammation, and can be applied to preparation of medicaments with corresponding effects. The preparation method of the helicid provided by the invention is simple to operate, can be used for large-scale industrial production, and overcomes the defect of insufficient yield of naturally extracted helicid.

The invention discloses a comprehensively degradable mulching film and a preparation method thereof, and relates to the field of agricultural biodegradable materials. The mulching film is prepared from polylactic acid, poly (butylene succinate), polycaprolactone, acetylated starch, nano cellulose whiskers and auxiliaries through vacuum drying, high-speed premixing, twin-screw extrusion granulation, film blowing forming and aging treatment. In the preparation process, by regulating and controlling the proportion of the polylactic acid base material, the substitution degree of the acetylated starch and the addition amount of the nanocellulose whiskers, a polymer-bio-based additive-nano reinforcement synergistic effect system is constructed, and optimal balance of the mechanical property and the biodegradation efficiency of the mulching film is achieved. The mulching film capable of being comprehensively degraded is suitable for the field of agricultural covering, can be completely degraded through the synergistic effect of microbial degradation and photooxidative degradation in the natural environment, solves the problem of residual pollution of a traditional mulching film, and meanwhile meets the mechanical supporting requirement in the crop growth period.

The invention provides a degradable plastic bag material and a preparation method thereof, and belongs to the field of plastic bag materials. The degradable plastic bag material is prepared from the following chemical components: 40 to 50 parts of polylactic acid, 15 to 25 parts of 3-hydroxybutyrate-co-4-hydroxybutyric acid copolymer, 5 to 15 parts of silane coupling agent modified starch, 3 to 8 parts of acetylated bamboo source nano cellulose, 5 to 15 parts of furan-terminated polylactic acid copolymer, 3 to 8 parts of bismaleimide dodecanedioate, 2 to 6 parts of coffee residue loaded WO3 and TiO2 and 1 to 5 parts of epoxidized soybean oil, the composition comprises the following components in parts by weight: 1-3 parts of sodium alginate microencapsulated lipase, 1-3 parts of quaternary ammonium salt modified hydrophilic kaolin, 0.1-1 part of zinc phenylphosphate and 0.1-0.8 part of polycarbodiimide. According to the application, the balance between the mechanical property and the degradation rate of the plastic bag material is realized through light-enzyme synergistic trigger degradation and dynamic covalent network regulation and control.

The invention relates to a buffer solution supporting multiple fluorescent quantitative PCR and a preparation method thereof, and relates to the technical field of biochemical reagents, the buffer solution comprises Tris-HCl, (NH4) 2SO4, KCl, a temperature control type magnesium ion nanocapsule and an additive; the additive is prepared from polyethylene glycol, betaine, trehalose, tetramethylammonium chloride and acetylated BSA (Bovine Serum Albumin); the temperature control type magnesium ion nanocapsule is of a core-shell structure, the core comprises MgCl2 accounting for 1-5 mM of the concentration of the buffer solution, pyrophosphatase accounting for 0.1-0.5 U / mu L, phospholipid accounting for 10-30 mg / mL, cholesterol accounting for 5-15 mg / mL and an inorganic solution, and the shell comprises a temperature-sensitive polymer accounting for 20-45 wt% of the concentration of the buffer solution. The buffer solution can dynamically adjust the concentration of Mg < 2 + >, and the situation that the amplification efficiency is affected due to the fact that the concentration of Mg < 2 + > is difficult to adjust is avoided.

Disclosed in the present invention is a method for preparing cationic acetylated glutinous rice starch having high freeze-thaw stability. The method comprises: measuring glutinous rice starch and sodium chloride, then adding same to distilled water, transferring same into a closed container, adding 3-chloro-2-hydroxypropyltrimethylammonium chloride and an alkali reagent thereto, sealing the container, mixing same until uniform, then performing an etherification reaction at a set temperature, finally adjusting the pH, and performing centrifugal washing, drying and grinding, so as to obtain cationic glutinous rice starch; and then adding the cationic glutinous rice starch, an acetic anhydride reagent and an alkali reagent to a closed container at 26°C, adjusting the pH at the same time, stirring same for a certain period of time, then reacting same at 25-30°C for 60-65 min, and centrifugally washing, drying and crushing a product obtained from the reaction, so as to obtain cationic acetylated glutinous rice starch having high freeze-thaw stability. The properties of the product of the present invention, such as a water-swelling property, solubility, freeze-thaw stability and paste transparency, are all improved, especially, the freeze-thaw stability is improved; and improvements in these properties broaden the application range of the product in food products and other fields.