343 results about "Dibasic acid" patented technology

The invention discloses an efficient wet desulfurization synergist and a preparation method thereof, and relates to the technical field of flue gas desulfurization. The efficient wet desulphurization synergist comprises the following raw materials in parts by weight: 10-20 parts of sodium formate, 5-10 parts of citric acid, 20-30 parts of binary acid, 5-6 parts of a surfactant, 15-20 parts of magnesium salt, 12-18 parts of sodium salt and 2-5 parts of a pH buffer agent. The preparation method comprises the following steps: reacting cyanuric chloride with lauryl amine to generate a monosubstituted compound; then reacting with L-asparaginic acid to generate a disubstituted compound; reacting with diethylenetriamine to generate a bis-triazine ring compound; and finally, reacting with sodium 2-chloroethanesulfonate to generate the surfactant. The high-efficiency wet desulphurization synergist prepared by the invention has a desulphurization effect.

The invention relates to the field of high polymer materials, and discloses a preparation method and application of high-temperature-resistant transparent modified polyester. The preparation method comprises the following steps: 1) blending 9, 9-di-[(4-phenylphenoxy) dibenzoic acid] fluorene with diacid and dihydric alcohol, and carrying out esterification reaction; and 2) carrying out condensation polymerization on the esterification product to obtain the high-temperature-resistant transparent modified polyester with the glass transition temperature of more than 70 DEG C. According to the invention, 9, 9-di-[(4-phenylphenoxy) dibenzoic acid] fluorene is used as a modification monomer, and is copolymerized with other dibasic acids and dihydric alcohols to synthesize the modified polyester, and the modified polyester has high transparency and still has good mechanical properties and dimensional stability at high temperature. Therefore, the high-temperature-resistant transparent modified polyester is applicable to the application fields of optical films, optical lenses, reflective protective films, optical fibers or liquid crystal displays and the like.

Disclosed in the present invention are a branched-chain-containing long-carbon-chain polyester elastomer based on biomass-based 2,5-furandicarboxylic acid, and a preparation method therefor. Monomers for preparing the polyester elastomer comprise 2,5-furandicarboxylic acid or 2,5-furandicarboxylic acid ester, a dihydric alcohol and a branched-chain-containing long-carbon-chain dibasic acid. The preparation method comprises: (1) performing a melting reaction on furandicarboxylic acid or an ester thereof, a branched-chain-containing long-carbon-chain dibasic acid and a dihydric alcohol to prepare an oligomer; and (2) performing melt polycondensation on the oligomer to synthesize a furandicarboxylic acid-based branched-chain-containing long-carbon-chain polyester elastomer. By means of the branched-chain-containing long-carbon-chain polyester elastomer of the present invention, the molecular structure can be effectively designed, and the molecular weight can be regulated, thereby optimizing mechanical properties, thermal properties, barrier properties, etc. The preparation process thereof is simple, convenient and safe, and the equipment requirements and catalysis cost are relatively low. The raw material 2,5-furandicarboxylic acid used in the present invention is a potential substitute for terephthalic acid, is derived from biomass, has a wide range of sources and is environmentally friendly.

The invention relates to the technical field of polymer dye synthesis, in particular to a polymer coloring agent based on a binary acid chromophoric monomer, a color master batch, a fiber and a preparation method of the polymer coloring agent. The structural formula of the diacid chromophoric monomer is as follows: # imgabs0. The chromophoric monomer has extremely high thermal stability, and can maintain the chemical structural integrity and chromophoric performance in a high-temperature environment (250 DEG C). The heat-resistant characteristic is mainly derived from a highly stable aromatic skeleton formed by a parent nucleus through an expanded conjugated system and a rigid plane structure, and heat vibration energy is effectively dispersed; in addition, a thermal stable group (an all-carbon skeleton) is introduced through side chain modification to form a steric hindrance effect, and molecular movement at high temperature is inhibited. Due to the unique heat resistance of the monomer, the monomer can be completely matched with a high-temperature processing window (240-300 DEG C) of a polyester melt polymerization process, and a polymer-dye composite system with a stable structure is constructed through covalent bonding in ester exchange and polycondensation processes.

The invention relates to the technical field of high polymer materials, and discloses self-repairing bio-based polyester resin for a matte powder coating as well as a preparation method and application of the self-repairing bio-based polyester resin. The bio-based polyester resin is prepared from the following preparation raw materials in percentage by mole: 20 mol% to 40 mol% of bio-based flexible diol, 20 mol% to 35 mol% of bio-based furandicarboxylic acid, 10 mol% to 25 mol% of isosorbide, 5 mol% to 25 mol% of itaconic acid, 1 mol% to 15 mol% of long-chain bio-based aliphatic dibasic acid, 1 mol% to 10 mol% of bio-based citric acid, 0.1 mol% to 2.0 mol% of zinc acetylacetonate, 0.1 mol% to 1.0 mol% of a microcapsule corrosion inhibitor, 0.1 mol% to 1.0 mol% of an esterification catalyst and 0.1 mol% to 1.5 mol% of an antioxidant. The bio-based polyester resin does not contain petroleum-based monomers and is high in biochar content.

The invention discloses a high-barrier material based on a PET aminolysis monomer and a preparation method of the high-barrier material, and belongs to the technical field of high polymer materials. The preparation method comprises the following steps: carrying out aminolysis reaction on polyethylene glycol terephthalate (PET) to prepare a dihydric alcohol monomer containing an amido bond, and carrying out polymerization reaction on the dihydric alcohol monomer and aliphatic dibasic acid to prepare a polyesteramide (PEA) material. The prepared PEA material has excellent oxygen barrier property and toughness, the oxygen barrier property of the PEA material is obviously superior to that of a PET material, and the barrier property and mechanical property of the PEA material can be regulated and controlled by changing the length of a methylene chain segment of the aliphatic dibasic acid monomer. The aliphatic dibasic acid monomer can be derived from biomass resources, the reaction condition is mild, the process is simple, and the method is suitable for industrial large-scale production.

The invention provides a novel hindered amine light stabilizer as well as a preparation method and application thereof, and relates to the field of light stabilizers. According to the preparation method of the novel hindered amine light stabilizer, specific dibasic acid dimethyl ester and 2, 2, 6, 6-tetramethylpiperidinol are used as raw materials, an alkane solvent or a benzene solvent is used as a solvent, and a catalytic reaction solution is obtained through a heating reaction under the condition of a catalyst; and neutralizing and washing the catalytic reaction liquid to obtain the novel hindered amine light stabilizer. According to the preparation method, ideal preparation effects (such as purity, yield and the like) can be achieved, meanwhile, the chroma of the product is effectively reduced, the problem that the product is prone to yellowing due to the fact that the hindered amine light stabilizer absorbs visible light is solved, and the compatibility and stability of the hindered amine light stabilizer and a high polymer material are further improved.

The invention provides a method for extracting and purifying long-chain dicarboxylic acid from fermentation liquor, which comprises the following steps: (1) controlling the pH value of the fermentation liquor to be less than or equal to 5 and the density to be 0.9-1.16 g / cm < 3 > to obtain a first solid-liquid mixture; (2) centrifuging the first solid-liquid mixture to obtain a second solid-liquid mixture of which the content of long-chain dibasic acid is greater than that of other solid substances and a third solid-liquid mixture of which the content of long-chain dibasic acid is smaller than that of long-chain dibasic acid in the second solid-liquid mixture; and (3) separating the second solid-liquid mixture to obtain the long-chain dicarboxylic acid. The method is simple to operate, low in equipment requirement and investment and high in treatment efficiency. And most thalli and impurities in the fermentation liquor are removed through centrifugal separation. And the obtained product has high purity and high product yield.

The invention relates to a method for recycling polyethylene plastic through catalytic oxidation cracking, and belongs to the technical field of plastic recycling. The method comprises the following steps: mixing a Co / Al2O3 catalyst, polyethylene plastic and water, and carrying out a catalytic reaction in an oxygen-containing atmosphere at a set temperature, so that the polyethylene plastic is converted into binary acid, thereby obtaining a reaction solution. The low-price Co / Al2O3 catalyst is applied to catalytic oxidation cracking of the polyethylene plastic, the polyethylene plastic is converted into the binary acid, the yield of the binary acid is stabilized at 70% or above and reaches 115% at most, and the Co / Al2O3 catalyst is low in price and low in cost. The low-cost and low-energy-consumption improvement of the yield of the binary acid converted from the polyethylene plastic through catalytic oxidation cracking is fully realized, and a new way is provided for the high-value conversion of the polyethylene plastic.

The invention provides a polyamide elastomer and a preparation method thereof. The method comprises the following steps: (1) under the action of a first catalyst, carrying out condensation polymerization on a poly-diol compound and a binary acid monomer in a solvent to obtain an end-capping reagent; (2) under the action of a second catalyst, an end-capping reagent and a comonomer are subjected to a contact reaction, and a polyamide block is obtained; and (3) in the presence of a stabilizer and under the action of a third catalyst, carrying out contact reaction on the soft segment and the polyamide block to obtain the polyamide elastomer, wherein the polydihydric alcohol compound is polyalkylene ether glycol with the number-average molecular weight of 150-2000, and the stoichiometric ratio of the polydihydric alcohol compound to the binary acid monomer is 1: (2.0-2.4); the comonomer is C4-C12 lactam and / or C4-C12 amino carboxylic acid; and the soft segment is a hydroxyl-terminated diol polymer. According to the invention, the performance loss of the hard-segment-dominated material is not caused on the basis of improving the soft-segment-dominated material mechanical property of the product, and the polyamide elastomer product with excellent comprehensive performance is obtained.

The invention provides aliphatic polyester and application thereof, the aliphatic polyester comprises dibasic acid residues and dihydric alcohol residues, the dibasic acid residues comprise the following residues: a1) 65-90 mol% of succinic acid residues based on 100 mol% of the total mole percentage of a1) and a2), and a2) 10-20 mol% of dihydric alcohol residues based on 100 mol% of the total mole percentage of a1) and a2); a2), 10-35 mol% of sebacic acid residues based on 100 mol% of the total mole percentage content of a1) and a2); the dihydric alcohol residues are selected from 1, 4-butanediol residues which are at least equal to the dibasic acid residues in molar weight; the aliphatic polyester contains an oligomer of which the number-average molecular weight measured by GPC is less than 1000, and the mass percentage content of the oligomer of which the number-average molecular weight measured by GPC is less than 1000 in the aliphatic polyester is 0.08-3.5 wt%. The packaging film prepared from the aliphatic polyester has good food contact performance and uncoiling performance.

The present invention relates to a photosensitive resin composition, a solder resist ink, a dry film and a cured product, the photosensitive resin composition contains an epoxy acrylic resin having a specific structure, and the epoxy acrylic resin having the specific structure is formed by adding an alpha, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, beta, and then adding dibasic acid anhydride to the beta-unsaturated monobasic acid a1 and the monobasic acid a2 with a specific structure. According to the invention, a certain proportion of monobasic acid a2 with a special structure is introduced into epoxy acrylate, so that the dispersibility of the photosensitive resin composition to pigments and fillers can be effectively improved; and the water absorption of the cured product is reduced, so that the lead-free tin spraying resistance and the wave soldering resistance are improved.

The invention provides an innovative solution of a bio-based synergistically modified polyester material, aiming at the problems of insufficient barrier property, lack of antibacterial property and the like of the traditional polyethylene glycol terephthalate (PET) material and the industrial problem of limited application scenes of food packaging, medical protection and the like caused by the problems of insufficient barrier property, lack of antibacterial property and the like. According to the scheme, the preparation method of the bio-based high-barrier antibacterial copolyester comprises the following steps: mixing 50-70 parts of binary acid, 20-40 parts of dihydric alcohol and 1-5 parts of an antibacterial agent, and carrying out esterification reaction to synthesize a PET antibacterial agent prepolymer; according to the invention, through a dual modification strategy of FDCA modified structure (using furandicarboxylic acid to replace part or all of terephthalic acid as a polymeric monomer) and natural antibacterial agent in-situ bonding, the synergistic breakthrough of barrier property and antibacterial efficiency in the polyester material is realized for the first time.

The invention belongs to the technical field of plasticizers, and particularly relates to a preparation method of a bio-based plasticizer. The invention provides a preparation method of a bio-based plasticizer, which comprises the following steps: carrying out esterification reaction on dibasic acid, oleic acid and dihydric alcohol under the action of a catalyst to obtain dibasic acid oleic acid dihydric alcohol ester; and carrying out epoxidation reaction on the diacid oleic acid dihydric alcohol ester and hydrogen peroxide under the action of weak acid and a catalyst to obtain the bio-based plasticizer. Dibasic acid, oleic acid and dihydric alcohol are used as raw materials, the bio-based plasticizer is synthesized through esterification reaction and epoxidation reaction, the plasticizer is applied to PVC, the machinable time of a PVC product on an open mill can be remarkably prolonged to 120 min or above, and the plasticizer has excellent extraction resistance and good aging resistance in various liquids and can be used for preparing PVC products. The plasticizer is a nontoxic plastic plasticizer with excellent properties.

The invention discloses a puncture-resistant packaging film and a preparation method thereof. The packaging film comprises a polyamide layer; the polyamide layer is prepared from the following raw materials in parts by mass: 70 to 90 parts of polyamide, 20 to 30 parts of modified polyamide and 5 to 10 parts of modified filler; the modified polyamide is prepared by the method comprising the following steps: carrying out condensation polymerization on a mixed monomer containing diamine, dibasic acid and polybasic acid to obtain a polyamide prepolymer; wherein the molar weight of the polybasic acid accounts for 5-10% of the total mole number of the dibasic acid and the polybasic acid; the preparation method comprises the following steps: carrying out melt esterification reaction on a polyamide prepolymer and polyester diol in a mass ratio of (10-25): (75-90) in the presence of a catalyst, and reacting a terminal hydroxyl group of the polyester diol with a carboxyl group of the polyamide prepolymer to obtain the modified polyamide. The problems that the polyamide material is high in rigidity and poor in puncture resistance can be effectively solved.

The invention belongs to the technical field of polyamide elastomers, and particularly relates to a polyamide elastomer and a method for preparing the polyamide elastomer through a one-pot method. The method for preparing the polyamide elastomer by the one-pot method comprises the following steps: (1) adding diamine, binary acid, polyether, deionized water and an auxiliary agent into a reaction container, carrying out heating reaction for the first time, then discharging to normal pressure, carrying out heating reaction again, and removing water and volatile components; (2) pre-diluting the esterification catalyst, adding the pre-diluted esterification catalyst into the reaction container, stirring, carrying out esterification reaction, then carrying out vacuum polymerization, and discharging and granulating after the reaction end point is reached to obtain a polyamide elastomer material; the one-pot polymerization process disclosed by the invention is beneficial to reducing the phase separation degree of a polyether soft segment and a polyamide hard segment; an esterification catalyst is added in the step (2), so that the phase separation degree of soft and hard segments can be better regulated and controlled, and the product performance is improved.

The invention discloses antibacterial and antistatic nylon as well as a preparation method and application thereof, and relates to the technical field of antibacterial materials. The preparation method of the antibacterial and antistatic nylon comprises the following steps: reacting a first mixed reaction system containing hexamethylenediamine, furandicarboxylic acid, binary acid and water to prepare a carboxyl-terminated prepolymer; and reacting a second mixed reaction system containing the carboxyl-terminated prepolymer, PEG (Polyethylene Glycol) and tetrabutyl titanate in a protective atmosphere to prepare the antibacterial and antistatic nylon block copolymer. The antibacterial and antistatic nylon prepared through condensation polymerization can improve the antibacterial performance of the PA66 base material, can also improve the antistatic performance of the PA66 base material, and can be used for preparing the antibacterial and antistatic PA66 material.

The invention discloses transparent resin as well as a preparation method and application thereof, and belongs to the technical field of polyester synthesis and application and development of polyester materials. The preparation method comprises the following steps: sequentially carrying out esterification reaction and polycondensation reaction on a mixture containing dibasic acid, dihydric alcohol, a catalyst and a stabilizer to obtain transparent resin; the binary acid is selected from at least one of terephthalic acid, 2, 5-furandicarboxylic acid and 2, 5-thiophenedicarboxylic acid; the dihydric alcohol is selected from at least two of ethylene glycol, 1, 4-butanediol, 1, 4-cyclohexanedimethanol, isosorbide and 2, 2, 4, 4-tetramethyl-1, 3-cyclobutanediol, and the dihydric alcohol is selected from at least two of ethylene glycol, 1, 4-butanediol, 1, 4-cyclohexanedimethanol, isosorbide and 2, 2, 4, 4-tetramethyl-1, 3-cyclobutanediol; the catalyst is selected from defect-state nano titanium dioxide; and the stabilizer is selected from triphenyl phosphate. By using the combination of the defect-state nano titanium dioxide catalyst and the triphenyl phosphate stabilizer, the polymerization reaction can be completed with high activity and low time consumption, and meanwhile, good transparency, excellent color, low ash content and excellent thermodynamic property of the product are kept.

The present invention discloses a furandicarboxylate bio-based crosslinkable elastomer and a preparation method thereof. The preparation method comprises: uniformly mixing furandicarboxylate or furandicarboxylate, a linear saturated dibasic acid or linear saturated dibasic acid ester, a linear unsaturated dibasic acid or linear unsaturated dibasic acid ester, and a diol; adding a catalyst and an antioxidant; heating the mixture to above 150°C; gradually heating the mixture under an inert atmosphere; and reacting the mixture at 150-190°C for 3-7 hours to obtain an intermediate product; stirring the intermediate product for a polycondensation reaction at a vacuum degree of 30-400 Pa and a temperature of 200-260°C for 3-8 hours to obtain a crude product; and dissolving, washing, and drying the crude product to obtain a finished product. The polyfurandicarboxylate bio-based elastomer prepared by the present invention has good mechanical properties and processing properties; and the composite material after crosslinking and filler reinforcement can greatly improve tensile strength, good resilience, low permanent deformation, and high tensile strength.

The invention provides a repairing method suitable for an engine case connecting bolt. The method comprises the following steps that S1, chemical stripping and fine treatment are conducted on the connecting bolt, an old plating layer on the surface of the connecting bolt is removed, and the surface of the connecting bolt is evenly coarsened; s2, a nitric acid-phosphoric acid binary acid system is adopted to conduct soaking treatment on the connecting bolt treated in the step S1 at the normal temperature, and a passive film on the surface of the connecting bolt is removed; s3, the connecting bolt treated in the step S2 is subjected to chemical nickel plating; and S4, the connecting bolt treated in the step S3 is subjected to hot water stabilization and dehydrogenation treatment, and the repaired connecting bolt is obtained. The invention provides a set of process from old plating layer removal, passive film removal and chemical nickel plating to hydrogen brittleness avoidance, so that the whole repair process is highly controllable, the product quality is stable and repeatable, and the problem of batch scrapping caused by batch difference and process uncontrollability in the prior art is solved.

The electrodialysis device comprises a membrane stack, electrode plates, fixing plates, a sealing assembly, a transparent baffle and a collecting assembly, the electrode plates are arranged on the two sides of the membrane stack, the fixing plates are arranged on the outer sides of the electrode plates, supports are arranged on the outer sides of the fixing plates, and the sealing assembly is arranged on the outer sides of the fixing plates. The sealing assembly comprises a fixing pipe arranged on the outer side of the fixing plate and an iron cover hinged to the fixing pipe, the transparent baffle is inserted into the fixing plate in a penetrating mode, and the collecting assembly comprises a collecting box arranged at the bottom of the transparent baffle, a discharging pipe arranged at the front end of the collecting box, a valve arranged on the discharging pipe and a liquid level sensor arranged on the inner side of the collecting box. By arranging the transparent baffle and the collecting assembly, under the condition that use of the electrodialysis device is not affected, the effect of conveniently collecting leaked liquid is achieved, whether leakage occurs or not can be monitored, meanwhile, the clamping assembly can be sealed through the sealing assembly, and the situation that the corrosion speed is increased due to the fact that dust and liquid make contact with the clamping assembly is avoided.

The invention belongs to the technical field of high polymer material additives, and particularly relates to a multifunctional additive, a synthesis method thereof and application of the multifunctional additive in PVC (polyvinyl chloride) processing. Modified mannitol and binary acid are used as raw materials for esterification reaction to obtain a product A, the product A and yttrium salt are mixed for reaction to obtain a product B, and the product B and cinnamyl ethyl methacrylate are mixed for free radical reaction to obtain the multifunctional additive. The multifunctional auxiliary agent can be used as a heat stabilizer to improve the thermal decomposition temperature of PVC, can also be used as a light stabilizer to reduce the influence of illumination on PVC, and can be well applied to PVC processing.

The application relates to a renewable and recyclable tourniquet and a preparation method thereof, and belongs to the technical field of tourniquet preparation. The tourniquet comprises the following raw materials in parts by weight: 70-95 parts of PBAT, 15-35 parts of a bio-based toughening agent, 10-20 parts of polyethylene, 5-10 parts of a modified inorganic filler, 1-3 parts of an antioxidant and 1-3 parts of a lubricant; the bio-based toughening agent is made from bio-based dibasic acid and bio-based trihydric alcohol through hyperbranched reaction. The bio-based toughening base, polyethylene and modified inorganic filler are introduced, the toughness of the PBAT base material is improved, the elastic performance of the obtained composite material is improved, and the obtained tourniquet meets the use requirements during hemostasis.

The present disclosure relates to a polyester formed by the reaction of a plurality of monomers, and the monomers include: 7 to 20 mole parts of (a) an aliphatic triol monomer; 40 to 80 mole parts of (b) a first diol monomer; 12 to 40 mole parts of (c) a second diol monomer; and 100 mole parts of (d) an aliphatic dicarboxylic acid monomer or an aliphatic acid anhydride monomer. The chemical structure of (b) the first diol monomer is as follows: or wherein each R 1 is the same. The chemical structure of (c) the second diol monomer is as follows: wherein R 6 is different from R 7 ​

This invention discloses a method for preparing low-density, high-filler SPC flooring. The method is characterized by a raw material formulation comprising the following components in the indicated weight proportions: 100 parts graft-modified PVC resin, 300-350 parts filler, 9-12 parts heat stabilizer, 3-5 parts melt processing modifier, 3-5 parts reinforcing and toughening modifier, 1-2 parts external lubricant, 1-2 parts internal lubricant, 2-5 parts chemical foaming agent, and 2-5 parts foaming aid. The graft-modified PVC resin is prepared by replacing the chlorine atoms in PVC with p-aminothiophenol, followed by an amidation reaction between a diacid or polyacid and an amino group. Its advantages are: 1) It improves the melt strength and expandability of the PVC resin, ensuring foaming performance under high filler content. Compared with ordinary SPC flooring, the flooring product has lower density and lighter weight, higher hardness, and lower overall formulation cost compared to ordinary low-density SPC flooring. 2) The process is simple, and the product has high controllability.

The invention provides a method for preparing alpha, omega-binary acid by decommissioning polyolefin cracking based on stage oxidation, which comprises the following steps: in the absence of a catalyst or in the presence of a catalyst, mixing decommissioning polyolefin with water to form a dispersion system, and reacting at the temperature of 100-200 DEG C and the partial pressure of oxidant gas of 0.1-5.0 MPa to prepare alpha, omega-binary acid. The method comprises the following steps: introducing oxidant gas into a high-pressure closed reactor, carrying out a stirring reaction to obtain small-molecular carboxylic acid, carrying out oxidation treatment on the small-molecular carboxylic acid by using nitric acid to obtain alpha, omega-dibasic acid with a carbon atom number of 4-10, and efficiently preparing high-purity alpha, omega-dibasic acid with a carbon atom number of 4-10. And [omega]-binary acid.

The invention discloses an optical encryption film material as well as a preparation method and application thereof, and the preparation method of the optical encryption film material comprises the following steps: uniformly mixing terephthalic acid, aliphatic dibasic acid and water to obtain a mixed aqueous solution; under the stirring action, 1, 5-pentamethylene diamine is slowly and dropwise added into the mixed aqueous solution, and a transparent salt solution is obtained; carrying out condensation polymerization reaction on the transparent salt solution to obtain nylon synthetic resin; preparing the nylon synthetic resin into a film; and carrying out two-way stretching on the film to obtain the optical encryption film material. The preparation method of the optical encryption thin film material is simple and low in cost, and the optical encryption material with higher cost performance can be prepared.

The application discloses a heterocyclic dibasic acid containing basic groups and a preparation method and application thereof. The heterocyclic dibasic acid containing basic groups has a structure shown in formula I: wherein Y comprises a substituted or unsubstituted heterocyclic group, and R1 and R2 are independently selected from a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. The heterocyclic dibasic acid containing basic groups can be used as an important chemical intermediate, and especially can be used as a chain extender for preparing polyurethane and the like.

A ceramic scintillator array 1 according to an embodiment of the present invention is provided with a plurality of scintillator segments 2 and a reflective layer. The reflective layer contains a resin composition. The resin composition contains a transparent resin and an additive. Dibasic acid esters serve as the additive.

The application discloses a diamine containing a DDSQ base element and a preparation method thereof, and belongs to the technical field of gas separation and purification. The preparation method of the diamine containing the DDSQ base element is suitable for synthesizing DSDQ functional molecules with different molecular structures and reaction activities, and meets the polymerization requirements. The preparation method of the polyimide gas separation membrane is as follows: firstly, a nitro aryl amine functional molecule is synthesized; then, the nitro aryl amine functional molecule is reacted with a DSDQ binary anhydride synthesized by using a disclosed technical solution to obtain a double-nitro compound containing the DSDQ; finally, the double-nitro compound is hydrogenated and reduced to obtain a target molecule, namely, a DSDQ diamine. The DSDQ diamine is condensed with a binary anhydride to obtain a polyamide acid precursor, and the polyamide acid precursor is cyclized and dehydrated to obtain a polyimide. Finally, the polyimide gas separation membrane containing the DSDQ base element is obtained by using a dissolving-tape casting method. The separation membrane still has stable gas permeability and relatively constant selectivity after physical aging for 300 days at room temperature, and has outstanding anti-aging performance.