38 results about "Pimelic acid" patented technology

The invention belongs to the technical field of medicines, and particularly relates to a pirfenidone eutectic crystal and a preparation method, a pharmaceutical composition and application thereof. The pirfenidone eutectic provided by the invention is prepared from pirfenidone and a eutectic ligand, and the eutectic ligand is selected from one of pimelic acid, cinnamic acid and saccharin. The pirfenidone eutectic crystal provided by the invention not only can improve the acute pancreatitis relieving effect of pirfenidone, but also can improve the safety of pirfenidone.

The invention belongs to the technical field of biochemical engineering, and particularly relates to a marine metagenome sourced meso-diaminopimelate dehydrogenase mutant and application thereof in D-tryptophan synthesis. According to the invention, a fast evolution method based on Rosetta guidance is adopted to modify meso-diaminopimelate dehydrogenase from a marine metagenome, and a mutant with high catalytic activity on 3-indolepyruvic acid is obtained through screening. The meso-diaminopimelate dehydrogenase mutant disclosed by the invention can be applied to direct catalysis of reductive amination of 3-indolepyruvic acid to generate chiral D-tryptophan, and can also be coupled with L-amino acid deaminase and coenzyme regeneration enzyme to realize configuration inversion from L-tryptophan to D-tryptophan, the substrate concentration reaches 0.1 M, and the product conversion rate is gt; the ee value is gt; therefore, the method has a relatively high practical application value.

The present invention discloses a meso-diaminopimelate dehydrogenase mutant of Proteus vulgaris and its application, belonging to the technical field of bioengineering. The present invention constructs a PvDAPDH mutant, which, compared with the wild enzyme, can catalyze the synthesis of D-amino acids from a variety of aromatic α-ketoacids, and the stereoselectivity can reach 95%. The triple mutant W121I / H227I / R181S of pvDAPDH constructed in the present invention shows good compatibility with different large-volume aromatic α-ketoacid substrates, can simultaneously catalyze the conversion of most aromatic α-ketoacid substrates into D-amino acids, shows high catalytic activity towards 2-oxo-4-phenylbutyric acid, and the yield of the product D-homophenylalanine reaches 2.1 g / L. The present invention effectively expands the toolbox for the biosynthesis of aromatic D-amino acids.

The invention relates to the technical field of polypropylene material production auxiliaries, in particular to a formula and a preparation method of a compound agent for beta-crystal polypropylene, the formula comprises a compound beta-crystal nucleating agent, a compound beta-crystal stabilizer and a compound antioxidant; the composite beta crystal nucleating agent comprises aryl dicarboxamide and calcium pimelate; the composite beta crystal stabilizer is prepared from beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylene bis-stearamide (EBS) WPP polypropylene wax. According to the invention, the first nucleating agent aryl dicarboxamide and the second nucleating agent calcium pimelate are matched for use, which is different from the existing scheme and method of independent use, so that the inductivity of the beta crystal is increased; and the beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate serving as a first stabilizer and the ethylene bis-stearamide (EBS) WPP polypropylene wax serving as a second stabilizer are matched for use, so that the beta crystal can be cured, and the produced polypropylene beta crystal is more stable.

This invention relates to the field of polymer materials technology, specifically to a modified sealing material based on polyphenylene sulfide (PPS) and its preparation method. This invention overcomes the problems of poor mechanical properties and poor thermal stability of existing sealing materials. In this application, PPS resin, nano-hexagonal boron nitride, calcium pimecronate, and a composite antioxidant are mixed to obtain a premix. This premix, PPS-grafted maleic anhydride, modified silica fume, and modified glass fiber are added stepwise through a twin-screw extruder, followed by extrusion granulation. Finally, variable mold temperature injection molding is used, with the mold temperature rising and then rapidly cooled during the filling stage to obtain the modified sealing material. This invention constructs a microscopic synergistic reinforcing network through a flexible polydopamine layer and a rigid inorganic phase, supplemented by rapid heating and cooling injection molding to eliminate residual internal stress and induce uniform and rapid crystallization of PPS, significantly improving the mechanical strength, fatigue life, and thermal stability of the molded part.

The invention discloses a wound repair material and a preparation method thereof, and relates to the technical field of medical materials. The wound repair material is prepared from the following raw materials in parts by weight: 50 to 60 parts of bioactive glass, 15 to 30 parts of chitosan, 10 to 20 parts of functional materials and 300 to 450 parts of deionized water. The preparation method comprises the following steps: reacting oleamide propyl dimethylamine with 4-chlorobutanol to generate an intermediate 1, reacting the intermediate 1 with 5, 10, 15, 20-tetra (4-carboxyl phenyl) porphyrin to generate an intermediate 2, and reacting the intermediate 2 with 4, 4 '-{[6-((1-carboxyl-2-mercaptoethyl) amino)-1, 3, 5-triazine-2, 4-diyl] bis (nitrounit)} bis [4-(2-carboxyethyl) pimelic acid] under the action of a photoinitiator to generate the functional material. The wound repair material prepared by the invention has excellent antibacterial property and hemostatic property.

The invention discloses a display protective film and a preparation method thereof, and relates to the technical field of film materials. When the display protective film is prepared, nano silicon dioxide is sequentially reacted with 2-(p-aminophenyl) ethyltriethoxysilane, 1-pyrazole methanol and zinc chloride to prepare modified nano silicon dioxide; the preparation method comprises the following steps: polymerizing ethylene glycol, dimethyl terephthalate, dimethyl phosphonite and dimethyl 4-pyridyl-4-pimelate to prepare polyester; the preparation method comprises the following steps: reacting polyester with 1-bromohexane to prepare modified polyester; and mixing the modified polyester, the modified nano silicon dioxide and a reversible cross-linking agent, and carrying out melt extrusion, sheet casting and two-way stretching to obtain the display protection film. The prepared display protective film has excellent antibacterial, self-repairing and mechanical properties.

A diaminopimelate dehydrogenase mutant and a use in D-amino acid synthesis. A diaminopimelate dehydrogenase mutant obtained by performing molecular modification on a Bacillus thermozeamaize diaminopimelate dehydrogenase, a nucleic acid encoding the diaminopimelate dehydrogenase mutant, a recombinant expression vector containing the nucleic acid, a recombinant expression transformant containing the recombinant expression vector, and a use of the diaminopimelate dehydrogenase mutant in the synthesis of a D-amino acid by means of the asymmetric reductive amination of a 2-keto acid. Compared with other D-biphenylalanine synthesis methods, the present invention has a simple route, a high theoretical yield, good atom economy, and a product optical purity of more than 99%. Therefore, the present invention relates to an environmentally-friendly, highly-stereoselective and green biological synthesis method, and has good prospects for application in actual production of D-biphenylalanine and other D-amino acids.

The application relates to the field of polypropylene materials, in particular to a high-rigidity low-warp polypropylene material for automobile structural parts and a preparation method thereof. The polypropylene material comprises the following components calculated in parts by mass: 50-65 parts of polypropylene resin, 10-15 parts of talcum powder, 2-5 parts of a compatilizer, 0.2-0.6 parts of an antioxidant, 0.5-1.5 parts of a lubricant, and 15-30 parts of modified glass fiber. The modified glass fiber is alkali-free chopped glass fiber grafted with a beta nucleating agent, and the beta nucleating agent comprises one or more of metal glutarate, metal pimelate, metal adipate, metal terephthalate and metal phthalate. By adding the modified glass fiber grafted with the beta nucleating agent, the warp deformation of the polypropylene material caused by the anisotropic distribution of the glass fiber is improved, the assembly precision of the automobile structural parts is met, and excellent rigidity is simultaneously achieved.

The invention relates to a biodegradable hollow plate master batch and a preparation process thereof. The biodegradable hollow plate master batch is prepared from the following raw materials in parts by weight: 30-50 parts of a first monomer; 5-30 parts of a second monomer; 3-20 parts of a third monomer; 2 to 12 parts of biomass filler; the first monomer is one of a cyclohexane dibasic alcohol compound, a polyester copolymer, organic acid esters, aromatic polyester and the like, and the second monomer is one of a dicarboxylic acid compound, succinic acid and the like; the dicarboxylic acid compound comprises adipic acid and pimelic acid. According to the invention, a first monomer is a cyclohexanediyl alcohol compound, the cyclohexanediyl alcohol compound is 1, 4-cyclohexanedimethanol, and a second monomer is succinic acid; the third monomer is polyethylene glycol terephthalate and has the characteristics of transparency, toughness, chemical corrosion resistance and the like, the mechanical property, the degradation property and the environmental friendliness of the material are practically balanced, and a material-level solution is provided for sustainable development.

The application belongs to the technical field of medicines, and particularly relates to a pirfenidone co-crystal, a preparation method thereof, a pharmaceutical composition and application. The pirfenidone co-crystal is prepared from pirfenidone and a co-crystal ligand, and the co-crystal ligand is selected from one of heptanedioic acid, cinnamic acid and saccharin. The pirfenidone co-crystal can not only improve the effect of pirfenidone in relieving acute pancreatitis, but also improve the safety of pirfenidone.

The application discloses a wound repairing material and a preparation method thereof, and relates to the technical field of medical materials. The wound repairing material comprises the following raw materials in parts by weight: 50-60 parts of bioactive glass, 15-30 parts of chitosan, 10-20 parts of functional material, and 300-450 parts of deionized water. The intermediate 1 is generated by the reaction of oleamide propyl dimethylamine and 4-chlorobutanol, the intermediate 2 is generated by the reaction of the intermediate 1 and 5,10,15,20-tetra(4-carboxyphenyl)porphyrin, and the functional material is generated by the reaction of the intermediate 2 and 4,4'-{[6-((1-carboxyl-2-mercaptoethyl)amino)-1,3,5-triazine-2,4-diyl]bis(nitrene)}bis[4-(2-carboxyethyl)heptanedioic acid] under the action of a photoinitiator. The wound repairing material prepared by the application has excellent antibacterial performance and hemostatic performance.

The invention discloses a metal ion complex for inhibiting urease and / or nitration and a preparation method thereof, the general molecular formula of the structure is M (DEP) (phen), M is a metal ion, DEP is diethyl pimelate, and phen is phenanthroline. Diethyl pimelate and phenanthroline are selected as ligands, preparation work is carried out through a multidentate coordination method, the technology is simple, the preparation difficulty is low, urease performance is remarkably inhibited, the degradation speed of urea can be effectively slowed down, the loss amount of nitrogen in soil is reduced, then the utilization rate of the nitrogen is increased, and favorable conditions are created for crop growth; the fertilizer can effectively reduce the conversion process from ammonium nitrogen to nitrate nitrogen in soil, reduces the nitrogen discharge amount in the fertilizer release process, is environment-friendly, and can improve the absorption efficiency of fertilizer nutrients.

The invention relates to escherichia coli engineering bacteria co-utilizing glucose and ethylene glycol and a method for producing L-lysine through fermentation of the escherichia coli engineering bacteria, a genetic engineering method is adopted to obtain a genetic engineering strain, and the genetic engineering strain substantially expresses ethylene glycol metabolism genes including ethylene glycol dehydrogenase, acetaldehyde dehydrogenase and glycollic acid dehydrogenase; and aspartic acid aminotransferase, aspartic acid kinase, aspartic acid semialdehyde dehydrogenase, 4-hydroxytetrahydrobipicolinate synthase, meso-diaminopimelate dehydrogenase, 4-hydroxytetrahydropicolinic acid reductase, pimelate decarboxylase, phosphoenolpyruvate carboxylase, tetrahydropicolinate acetyltransferase, N-acetyl-L, L-dihydroxypicolinate, N-acetyl-L, L-dihydroxypicolinate, N-acetyl-L, L-dihydroxypicolinate, N-acetyl-L, L-dihydroxypicolinate and N-acetyl-L-dihydroxypicolinate. L-diamino pimelic acid amino transaminase and N-acetyl diamino pimelic acid deacetylase are added into the reaction system; the gene engineering strain is an E.coli BW25113 strain of which the genes of ldhA, pta, poxB, adhE, pflB, mgsA, frdA, cadA, ldcC, yqhD and ycdW are substantially inactivated. The genetic engineering strain is subjected to fermentation culture by taking glucose and ethylene glycol as carbon sources, and L-lysine is separated from a culture after the culture is finished.

To provide methods and systems to decompose contaminated plastic waste and transform it into value-added products.SOLUTION: A method for decomposing contaminated plastic waste comprises the steps of: (a) adding contaminated plastic waste to a reaction vessel; (b) adding aqueous nitric acid (HNO3) to the reaction vessel to give a mixture, wherein the weight ratio of plastic waste to aqueous nitric acid is greater than 1:3; and (c) subjecting the mixture obtained in (b) to conditions effective to decompose the plastic waste to produce decomposition products, wherein the decomposition products comprise: (i) succinic acid, glutaric acid, adipic acid, pimelic acid, and azelaic acid, and (ii) at least one of C8 to C20 dicarboxylic acid substituted with a single nitro group, or the salts or esters thereof.SELECTED DRAWING: None

The invention provides an anti-ultraviolet toughness-enhanced injection molding storage box and a preparation process thereof, and relates to the technical field of daily plastic products, the injection molding storage box comprises the following raw materials: a polypropylene copolymer, a styrene-ethylene-butadiene-styrene copolymer, an anti-UV complexing agent, pimelic acid modified nano calcium carbonate and the like. The preparation process of the injection molding storage box comprises the following steps: respectively modifying the nano titanium dioxide and the nano calcium carbonate; all the components are mixed and then extruded and granulated; and carrying out injection molding to obtain the injection molding storage box. According to the injection molding storage box, the blend of PP and SEBS is selected as a blending system, and meanwhile, the pimelic acid modified nano calcium carbonate and the anti-UV complexing agent are added, so that the injection molding storage box has good mechanical properties, ultraviolet resistance and toughness.

The invention relates to the field of polypropylene materials, in particular to a high-rigidity low-warpage polypropylene material for automobile structural parts and a preparation method of the high-rigidity low-warpage polypropylene material. The polypropylene material comprises the following components in parts by mass: 50-65 parts of polypropylene resin; 10 to 15 parts of talcum powder; 2 to 5 parts of compatilizer; 0.2 part to 0.6 part of an antioxidant; 0.5 to 1.5 parts of a lubricant; 15 to 30 parts of modified glass fiber; wherein the modified glass fiber is alkali-free chopped glass fiber grafted with a beta nucleating agent, and the beta nucleating agent comprises one or more of glutaric acid metal salt, pimelic acid metal salt, adipic acid metal salt, terephthalic acid metal salt and phthalic acid metal salt. By adding the modified glass fiber with the surface grafted with the beta nucleating agent, buckling deformation, caused by anisotropic distribution of the glass fiber, of the polypropylene material is improved, the assembly precision of automobile structural parts is met, and meanwhile the excellent rigidity is achieved.

A gold-based alloy solder paste with good dispensing performance, comprising, in mass percentage, 87-93% of gold-based alloy powder, the gold-based alloy powder containing 75-90% of gold; and 7-13% of flux, the flux mainly comprising modified rosin, organic solvent, active agent and thixotropic agent; the modified rosin being hydrogenated rosin and polymerized rosin; the organic solvent being two or more of ethylene glycol, glycerol, isopropyl alcohol, diethylene glycol ethyl ether, propylene glycol methyl ether or dipropylene glycol butyl ether; the active agent being one or more of acetic acid, glutaric acid, o-hydroxybenzoic acid, pimelic acid and heptanedioic acid; and the thixotropic agent being ethylene bis-stearamide and modified fatty acid amide resin; the gold-based alloy solder paste prepared by the application is free of halogen, easy to clean, low in oxygen content, has bright solder joints and high expansion rate, can realize continuous dispensing, and is applied to the field of high-reliability electronic packaging.

The invention discloses a novel binuclear chiral catalyst for preparing S-epichlorohydrin with high optical purity as well as a synthesis method and an application method of the novel binuclear chiral catalyst. The molecular formula of the catalyst is [Co2L (Y) 2]. NH2O, L is a Salen tetradentate ligand formed by condensation of (R, R)-1, 2-cyclohexanediamine, 3-tert-butyl-2, 5-dihydroxybenzaldehyde and 4-oxa-1, 7-pimelic acid, and Y is a sulfonate radical or an acetate radical. The preparation method comprises the following steps: carrying out acidic hydrolysis on 2-cyanoethyl ether to obtain 4-oxa-1, 7-pimelic acid; 2-tert-butylhydroquinone is subjected to protection, formylation and deprotection, and benzaldehyde is prepared; carrying out condensation on the Salen ligand and (R, R)-1, 2-cyclohexanediamine to generate dialdehyde, and cyclizing the dialdehyde with (R, R)-1, 2-cyclohexanediamine to obtain a Salen ligand; and finally, complexing with cobalt acetate and acid under nitrogen to separate out a catalyst crystal. When the catalyst is used for epoxy chloropropane water-phase resolution and gas-phase detection, the reaction is terminated when ee is greater than or equal to 99.5%, the catalyst is directly filtered and recovered, the S-epoxy chloropropane is obtained through reduced pressure distillation, the ee is still greater than or equal to 99.0% after the catalyst is circulated for five times, and the recovery rate is greater than or equal to 92%.

The present invention relates to the field of pharmaceutical technology, and particularly, to a pirfenidone co-crystal and a method for preparing same, a pharmaceutical composition, and use thereof. The pirfenidone co-crystal provided in the present invention is prepared from pirfenidone and a co-crystal ligand selected from one of pimelic acid, cinnamic acid, and saccharin. The pirfenidone co-crystal provided in the present invention can not only improve the effect of pirfenidone in relieving acute pancreatitis, but also improve the safety of pirfenidone.

The present invention provides an L-lysine producing strain, a method for constructing the same and an application thereof. The strain uses E.coli W3110 as the starting strain, and has knocked out pflB, adhE, ldhA, ackA, frdBC, poxB, lacI, cadA, ldcC genes, up-regulated pntAB, ppc, aspC, lysC V339A , asd, dapA H56K , dapB, lysA, lysE genes, heterologously expressed the Corynebacterium glutamicum genes derived from ddh K051. The strain has knocked out some by-products and lysine degradation pathway enzymes, strengthened the diaminopimelic acid pathway and the supply of NADPH of the strain, and can efficiently synthesize L-lysine using glucose as a substrate, and has a high production level.

Rubber composition for the manufacture of a tread for a winter tire, which contains: a rubber component, (a) a zinc salt of an aliphatic C4-C 12 -carboxylic acid or (b) an aliphatic C4-C 12 -carboxylic acid and zinc oxide and an oil or a plasticizer, wherein the rubber component contains 45 mass% or more of butadiene rubber based on 100 mass% of the rubber component, wherein the amount of the zinc salt (a) and the amount of the mixture (b) are 0.2 parts by mass or more and 10 parts by mass or less, respectively, based on 100 parts by mass of the rubber component, and where in case (a), in the case of a zinc salt of an aliphatic C4-C 12 -carboxylic acid, the aliphatic C4-C 12-Carboxylic acid is a saturated fatty acid selected from the group consisting of heptanoic acid, nonanoic acid, undecanoic acid, isobutanoic acid, isopentanoic acid, pivalic acid, isohexanoic acid, isoheptic acid, isooctanoic acid, dimethyloctanoic acid, isononanoic acid, isodecanoic acid, isoundecanoic acid, isododecanoic acid, 2-ethylbutanoic acid, 2-ethylhexanoic acid, 2-butyloctanoic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and sebacic acid or an unsaturated C4-C 12 -fatty acid and where in case (b), with an aliphatic C4-C 12 -carboxylic acid and zinc oxide, the aliphatic C4-C 12-Carboxylic acid is a saturated fatty acid selected from the group consisting of butanoic acid, pentanoic acid, heptanoic acid, nonanoic acid, undecanoic acid, isobutanoic acid, isopentanoic acid, pivalic acid, isohexanoic acid, isoheptic acid, isooctanoic acid, dimethyloctanoic acid, isononanoic acid, isodecanoic acid, isoundecanoic acid, isododecanoic acid, 2-ethylbutanoic acid, 2-ethylhexanoic acid, 2-butyloctanoic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and sebacic acid or an unsaturated C4-C 12 -fatty acid.

The present invention belongs to the field of drug synthesis, and is particularly related to a novel method for preparing 6-aminocaproic acid using pimelic acid as a raw material, using pimelic acid with abundant sources as a reaction raw material, undergoing acylation and cyclization reaction with acetic anhydride, and then undergoing substitution reaction with ammonia, and finally purifying after ring opening in an alkaline system to obtain 6-aminocaproic acid pure product. The reaction process is simple and post-processing is convenient; acetic anhydride is added in excess, and during the reaction process, acetic anhydride serves as both a reaction raw material and a reaction reagent, ensuring that the reaction can proceed in a positive direction and improving the conversion rate; the 6-aminocaproic acid obtained by the present invention has a purity of more than 97%, a yield of more than 85%, and is suitable for large-scale production.

The application discloses a kind of polypropylene microcellular foaming material with high beta crystal content and a preparation method thereof.The nano calcium carbonate or partially organicized nano calcium-based montmorillonite is mixed with pimelic acid to obtain nano-particle loaded calcium pimelate, then polypropylene resin and nano-particle loaded calcium pimelate are mixed, extruded, granulated, and molded to obtain a sample to be foamed, the sample to be foamed is sealed in an autoclave, and a two-step temperature control foaming is used to obtain a polypropylene microcellular foaming material with high beta crystal content.The polypropylene microcellular foaming material prepared by the method has stable cell quality and a beta crystal content of more than 50%.

A thermoplastic molding composition comprising at least one thermoplastic polyamide, as com-ponent A; red phosphorous, as component B; at least one fibrous and / or particulate filler, as component C; and wherein component A comprises at least one polyamide of A1) units derived from 1, 5-pentanediamine as component A1; A2) units derived from at least one aliphatic dicarboxylic acid, preferably selected from the group consisting of adipic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid, as component A2; A3) units derived from at least one aromatic dicarboxylic acid, preferably selected from the group consisting of terephthalic acid, isophthalic acid, and phthalic acid, as component A3; wherein the molar ratio of component A1 to the sum of components A2 and A3 is 1-1.05 to 0.95; a process for preparing of the inventive thermoplastic molding composition; the use of the in-ventive thermoplastic molding composition for producing fibers, foils or moldings; and fibers, foils or moldings comprising the inventive thermoplastic molding composition.

The invention relates to the technical field of macromolecule toughening modification, in particular to a PPR pipe with low-temperature-resistant toughness and a preparation technology of the PPR pipe. Comprising the following steps: preparing boron-ene microspheres; and carrying out blending injection molding and graded pressure annealing on the composite PPR pipe of the polystyrene, the boron-ene microspheres and the calcium pimelate. The prepared injection-molded PPR pipe is placed in a high-pressure and high-temperature annealing furnace to be subjected to pressurized annealing treatment, the annealing and heat preservation time can be remarkably shortened, so that the production efficiency is improved, meanwhile, uniform distribution of the internal temperature of the material is facilitated through pressurized annealing, the overall mechanical property is improved, arrangement and orientation of polymer molecular chains are effectively promoted, and the service life of the injection-molded PPR pipe is prolonged. The low-temperature and normal-temperature toughness of the PPR pipe can be improved by changing the movement behavior of a polymer chain through annealing in a pressurized environment, the brittle fracture risk is reduced, internal stress can be released more quickly, regeneration of the internal stress is prevented, and the stability of the PPR pipe is improved.

The invention discloses a production method of a BOPP capacitor film. The capacitor film comprises an upper surface layer, a base layer and a lower surface layer, the upper surface layer is composed of PP, boron nitride, a cycloolefin polymer, calcium pimelate, paraffin and an antioxidant; the base layer is prepared from PP, low-molecular-weight polybutylene, chopped glass fibers, pimelic acid modified oyster shell powder and a coupling agent; the lower surface layer is composed of PP, magnesium salt whiskers, liquid ethylene propylene diene monomer and kaolin. The capacitor film prepared by the invention has relatively good mechanical properties and heat resistance.

The invention relates to the technical field of essence, and particularly discloses an ester compound with fresh fruit fragrance and a preparation method thereof. The chemical name of the prepared compound is 4-methoxycarbonyl-4-carbobenzoxycarbonyl-1, 7-dimethyl pimelate, and the compound provided by the invention has a fresh citrus fruity fragrance and a little fresh flower sweet fragrance, is elegant in fragrance and long in fragrance holding time, and has important application in the field of daily chemical flavoring.

The invention relates to a novel tizanidine salt and a preparation method thereof, and belongs to the technical field of pharmaceutical chemicals. The novel tizanidine salt is obtained by selecting low-corrosivity and weak-acidity organic carboxylic acid as a ligand through a cooling crystallization or solvent evaporation crystallization mode. Wherein the organic carboxylic acid is selected from salicylic acid, p-hydroxybenzoic acid, maleic acid and pimelic acid. The formed tizanidine salicylate is in a P21 / n space group of a monoclinic system; the tizanidine p-hydroxybenzoate is an orthorhombic crystal system and has a Pbcn space group; the alpha crystal form of the tizanidine maleate is a P21 / c space group of a monoclinic system; the beta crystal form of the tizanidine maleate is a P21 / c space group of a monoclinic system; the tizanidine pimelate is an orthorhombic crystal system and has a Pna21 space group. The dissolution rate and the inherent dissolution rate of the tizanidine are improved in a mode of forming salt through crystal engineering, the obtained novel tizanidine salt has good stability, the bioavailability of the tizanidine is improved so that the tizanidine salt can give full play to the curative effect, the preparation condition is mild, the reproducibility is good, and large-scale production is easy to realize.

The application belongs to the technical field of polymer materials, and particularly relates to a PP-R cold and hot water pipe and a preparation method thereof. The PP-R cold and hot water pipe provided by the application comprises PP-R resin, composite nucleating agent, impact agent, filler, gamma-aminopropyl triethoxysilane, polyvinyl alcohol, antioxidant and color masterbatch. The reaction product of benzoic anhydride and p-phenylenediamine is reacted with cerium nitrate to generate a diamide carboxylate, which is compounded with calcium pimelate to form a beta nucleating agent, so that the low-temperature plasticity of the PP-R cold and hot water pipe is improved. The low-impact polypropylene is used to wrap modified nano zeolite powder as the impact agent, so that the impact resistance and high-temperature performance of the PP-R cold and hot water pipe are improved. The cooling rate of the PP-R cold and hot water pipe after extrusion molding is controlled, and heat preservation treatment is performed, so that the internal stress of the PP-R cold and hot water pipe is effectively eliminated, and the beta crystal content and crystallization ability are improved. The carbon nanofiber and nano silicon dioxide are selected to jointly form the filler, so that the mechanical properties of the PP-R cold and hot water pipe are improved.