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Polyester especially polyethylene terephthalate PET is widely used in the textile and apparel industries due to its excellent thermal mechanical and chemical stability. However with increasing consumption the environmental impact of waste polyester fibers has become increasingly pronounced. The problem in biodegrading PET poses technical challenges for the recycling and reuse of waste polyester particularly in terms of efficient depolymerization and the recovery of valuable chemical monomers. Traditional methods for dealing with waste polyester are plagued by low efficiency high costs cumbersome processes and significant environmental pollution. Therefore developing efficient economical and energy-conserving recycling technology for waste polyester is significant for alleviating environmental pressure and achieving resource recycling. This study aims to explore a novel water-solvent thermal technology for the efficient depolymerization of waste polyester and the recovery of terephthalic acid TPA providing a new approach for the highvalue recycling of waste polyester. To efficiently depolymerize waste polyester and recover TPA this study employed water-solvent thermal technology. Waste polyester pellets were treated with an alkaline water-methanol solution under high temperature and pressure followed by the precipitation of TPA using sulfuric acid. The process conditions for the depolymerization of polyester in the alkaline water-methanol solution were optimized. Various analytical techniques including Fourier transform infrared spectroscopy FTIR nuclear magnetic resonance NMR spectroscopy and high-performance liquid chromatography HPLC were used to characterize the chemical properties and purity of the obtained TPA. Additionally the VeriVide DigiEye Roachelab system was used to evaluate the color characteristics of the product. The use of hydro-solvent thermal technology in this study achieved efficient depolymerization of waste polyester and the use of sulfuric acid facilitated the efficient precipitation of TPA. The systematic optimization of depolymerization process parameters provided a basis for further improving the recovery rate and reducing costs. The experimental results showed that when waste polyester granules were treated in a mixture containing 50 g / L of sodium hydroxide and 100 mL/ L methanol at 160 ℃ for 2. 5 hours with a bath ratio of 1︰20 the recovery rate of TPA was calculated to be 94. 9% . The chemical properties of the separated product as indicated by FTIR NMR and HPLC analysis were highly consistent with the TPA standard showing a purity of 90. 53% . However the color difference between commercial TPA and the obtained TPA was 16. 02 according to the VeriVide DigiEye Roachelab system indicating the presence of a small amount of light yellow impurities. This study has significant value in practical application and environmental protection. The optimization of depolymerization conditions provides key reference information for the industrial-scale recycling of waste polyester which can help improve production efficiency and effectively reduce economic costs. Moreover this study proposes a new method for the efficient recovery of TPA from waste polyester which not only reduces the potential environmental impact of waste polyester fibers but also promotes the further development of the circular economy. However there are some limitations in the research process that point the way for future work. For example the TPA product obtained in the experiment shows a significant color difference compared to the standard one indicating that the product contains a certain amount of impurities. This necessitates the exploration of more effective purification technologies in future research to improve the purity and quality of the product. Additionally during the experimental process ethylene glycol EG was observed in the hydrolysate but due to its low content it is difficult to achieve effective separation. This issue also needs to be resolved in future research to fully recover and utilize all valuable components in waste polyester. In summary although this study has made positive progress in the depolymerization of waste polyester and the recovery of TPA further research and improvement are still needed to overcome current challenges and achieve a more efficient and environmentally friendly recycling process. [ABSTRACT FROM AUTHOR]

In view of the recovery and utilization of vanadium from vanadium extraction tailings, the alkaline pressure leaching technology was proposed to realize the leaching and extraction of vanadium from vanadium extraction tailings. The raw material was analyzed and the effects of temperature, sodium hydroxide concentration, reaction time, liquid-solid ratio and stirring speed on the leaching rate of vanadium, chromium and silicon in the tailings were investigated. The results indicate that the leaching rate of vanadium can be controlled at 50% when the temperature is 120 °C, the dosage of sodium hydroxide is 10%, the liquid-solid ratio is 4-6 mL/g, the time is one hour, and the stirring speed is 400 r/min. At the same time, the leaching of chromium and silicon is reduced as much as possible. The purification degree of the solution is maintained, and good solution conditions are provided for the subsequent extraction of vanadium. [ABSTRACT FROM AUTHOR]

To monitor radioactivity and its emissions in retired nuclear facilities, this study established an analytical method for 63 Ni and 55 Fe in mixed soil samples from a decommissioning reactor. After ashing at 400 °C for 4 hours, the sample was dissolved in a mixture of concentrated hydrochloric acid, nitric acid, and hydrofluoric acid, and then heated to dryness and dissolved in 9 mol/L hydrochloric acid. Subsequently, 63Ni and 63Fe were separated and purified using sodium hydroxide precipitation, anon exchange chromatography, and nickel specific rein extraction, and then measured by the liquid scintillation method. The results showed that the final stable recovery rates of Ni and Fe were 98.8% and 95.8%, respectively. The minimum detection limit and minimum detectable activity for 63Ni and 55Fe were 208 (counting) and 0.041 Bq,208 (counting) and 0.144 Bq, respectively. The actual activity concentrations of 63Ni and 55Fe in the samples were 76.9 Bq/g and 30.4 Bq/g, respectively. The recovery simulation experiment was conducted using standard soil substances, achieving a recovery of over 95%. Experiments were conducted on the separation of Ni and Fe from various elements using alkali precipitation and anon exchange chromatography, respectively. Among them, the sodium hydroxide precipitation method effectively coprecipitated Ni and Fe, and removed most of Re,Sr, and all Cs at pH value between 8.7 and 11.1. The decontamination factors for Co,Fe, and Zn in the nickel fraction of anion exchange chromatography were all above 660, wide the decontamination factors for Co,Eu,Mn,Ni, Sr,Zn, and Zr in the iron fraction were all above 2 000. This work also investigated the purification effects of DMG precipitation method and nickel specific resin method on Ni, respectively. The recovery of Ni by DMG precipitation method was 87.14%, and the recovery of Ni by nickel resin method was close to 100% when the nickel interference element ratio was above 10:1. Moreover, the purification effect of interference elements such as Ba, Eu, Fe, Mn, and Sr was the best. Therefore, before using nickel resin, other methods such as alkali precipitation and ion exchange resin should be used for preliminary separation. This method is simple to operate and has a high recovery, which can meet the needs of monitoring 63Ni and 55Fe in retired nuclear facilities. [ABSTRACT FROM AUTHOR]

A spodumene from the Democratic Republic of Congo (DRC) has a Li2O grade of 0.86%, classifying it as a low-grade and refractory lithium ore. To achieve efficient and comprehensive utilization of this spodumene, a joint flotation - magnetic separation test was conducted. The results indicate that under the conditions of grinding fineness of -0.074 mm accounting for 75.0%, the addition of 500 g/t sodium carbonate, 140 g/t calcium chloride, 700 g/t sodium hydroxide in the ball mill, and 200 g/t sodium hydroxide in the flotation cell, along with 1 650 g/t of reagent combination A (a mixture of oxidized paraffin soap and oleic acid in a mass ratio of 1:3), a closed-circuit test with roughing once, scavenging twice, cleaning three times, and magnetic separation once produced a non-magnetic product with a Li2O grade of 5.67% and a Li2O recovery rate of 77.71%. Additionally, a magnetic product with a Li2O grade of 4.51% and a Li2O recovery rate of 10.51% was obtained. The test results are favorable, providing a valuable reference for the comprehensive utilization of spodumene resources. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of the study was to improve the cell wall-breaking rate of industrial Saccharomyces cerevisiae and its application value. The effects of heat, alkali and ultrasonic synergistic treatment on the cell wall-breaking rate of industrial Saccharomyces cerevisiae ScY01 strain were explored. The results showed that the wall-breaking rate of ScY01 strain with a concentration of 6 g/L was 91.78% when treated with heat (boiling water bath 12.5 min), alkali (sodium hydroxide 0.6 g) and ultrasonic crushing (ultrasonic power 450 W, radiation time 11 s, radiation interval 15 s, ultrasonic time 20 min). The amount of protein released after cell fragmentation was used for preliminary application characterization, the total protein release by synergistic treatment was 11.54 times higher than that of alkali alone, 10.26 times higher than that by boiling alone, and 4.01 times higher than that by ultrasonic alone. The study indicates that the synergistic treatment is suitable for model Saccharomyces cerevisiae strain CEN.PK2-1c, and the experimental results can provide a new method for efficient crushing of industrial Saccharomyces cerevisiae cells. [ABSTRACT FROM AUTHOR]

The aim of this study is to explore new ways of resource utilization of lithium pyroxene tailings and refining slag. The effects of sodium hydroxide addition, water glass addition and the doping ratio of lithium pyroxene tailings and refining slag on the mechanical properties of geopolymers were analyzed through one-way and orthogonal experiments. On this basis, we focused on the influence of the change of sodium hydroxide addition on the preparation of lithium pyroxene tailings-refining slag based geopolymer and its mechanical properties, and analyzed the influence of sodium hydroxide on the microstructure of geopolymer by using the characterization means such as XRD, SEM, FT-IR and so on. The results showed that the 28 d compressive strength of the geopolymer was up to 26.78 MPa when the ratio of lithium pyroxene tailings to refinery slag was 73, the addition of water glass was 15 mL, and the addition of sodium hydroxide was 2 g. The addition of sodium hydroxide had the most significant effect on the preparation of geopolymer among the three influencing factors. When the alkalinity of lithium pyroxene tailings was too high, the dissolution of silica-oxygen tetrahedra and aluminium-oxygen tetrahedra was slowed down or inhibited, thus affecting the synthesis of C-S-H gels and N-A-S-H gels. XRD and SEM analyses showed that, with the increase of the content of sodium hydroxide, the generated gels firstly increased and then decreased, and at the same time, they combined with the substances such as bluestone, which increased the degree of densification of the geopolymer. In addition, the loss of compressive strength of the lithium pyroxene tailings-refinery slag-based geopolymer was small at 800 indicating its good high temperature resistance. [ABSTRACT FROM AUTHOR]

A method for determining thiocyanate in cyanide residue has been developed. Through experiment on test conditions, it was determined that a 0.8% sodium hydroxide solution should be used as the leaching agent, with the leaching process involving ultrasonic extraction for 5 min followed by heating on a hot plate at 180 °C for 1 h. Thiocyanate was then measured using the ferric salt colorimetric method. The relative standard deviation of this method ranged from 0.12% to 0.93%, with spiked sample recovery rates between 95.46% and 100.50%. This method has been widely applied for the determination of thiocyanate in cyanide residue within the gold industry. [ABSTRACT FROM AUTHOR]

As a rich symbiotic mineral resource, orpiment (As2S3) and realgar (AsS/As2S2/As4S4) are common sulfide minerals of arsenic. However，due to their similar chemical properties, the chemical phase analysis method of arsenic has always taken these two minerals as the same phase analysis and determination, and cannot obtain their respective contents. In the research, the orpiment and realgar arsenic ores of Shimen in Hunan Province were taken as the object. The separation conditions of orpiment and realgar samples were studied by single-mineral selective separation technology. The single mineral of orpiment and realgar was leached with 4mol/L ammonia solution and a 35℃ water bath for 6h. The extraction rate of orpiment and realgar was 92.2% and 2.4% respectively. Realgar was leached with sodium hydroxide solution, the extraction of realgar was 75.8%. Due to the spatial structure of realgar being oxidized, the addition of iodine can oxidize it into arsenic oxide that is easily soluble in alkali, increasing the extraction rate to 92.2%. The building of the selective separation conditions lays the foundation for the development of chemical phase separation methods for arsenic ores mainly composed of orpiment and realgar. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High purity ultrafine flame retardant magnesium hydroxide powder was prepared by the liquid phase precipitation method using magnesium sulfate as raw material, sodium hydroxide as precipitant, and sodium stearate (NaSt) and polyethylene glycol (PEG2000) as surfactants. The effects of precipitation mode, reactant ratio, reaction temperature, stirring rate, reaction time, surfactant ratio, surfactant dosage, and washing method on the particle size of magnesium hydroxide powder were investigated. The product morphology, crystalline phase structure, particle size and its distribution, purity, dispersion effect, and wettability were tested. The results show that the suitable process conditions for the preparation of ultrafine magnesium hydroxide are as follows: the precipitation method is two-way precipitation, n(NaOH):n(MgSO4)= 2.5:1.0, the reaction temperature is 60 °C, the stirring rate is 400 r/min, the reaction time is 50 min, the ratio of NaSt/PEG2000 is 4:1, the addition amount is 4 g/mol MgSO4, and the washing method is pure water washing for three times. The surface of the obtained magnesium hydroxide is hydrophobic, the contact angle is up to 123.50°, the dispersion is good, the purity is as high as 99.50%, the average particle size is 3.83 μm, and the particle size distribution is uniform and hexagonal lamellar crystal. The whiteness, purity and particle size of the sample met the magnesium hydroxide index for flame retardant. [ABSTRACT FROM AUTHOR]

In this study, xylose was used as the raw material, combined with sorbitol and citric acid to prepare xylo-oligosaccharides by high-temperature polycondensation. Then, a certain amount of xylo-oligosaccharides were mixed with sodium hydroxide solution to prepare nanoxylan by heat reaction. The results showed that when the material ratio of xylose, sorbitol, and citric acid was 18 : 6 : 1, the processing temperature was 170 °C, and the processing time was 1 h, the yield of xylo-oligosaccharides was the highest. When the sodium hydroxide concentration was 3.5%, the treatment temperature was 60 °C, and the treatment time was 2 h, the obtained nanoxylan exhibited a smaller particle size. The antibacterial experiment was carried out with Staphylococcus aureus and Escherichia coli as experimental strains. The diameter of the inhibition circle in Staphylococcus aureus and Escherichia coli was 11 mm and 12 mm, respectively, which showed a good antibacterial effect. [ABSTRACT FROM AUTHOR]

High performance phenolic lignin-furfural adhesive was prepared by using highly reactive phenolic lignin. Two new peaks appeared at 756 cm-1 and 695 cm-1 after phenolization of lignin, which confirmed the substitution reaction between hydroxyl group at α position of lignin side chain and the active site of phenolic ring. Under the molar ratio of furfural and phenol of 1.4/1, the mass ratio of furfural and lignin of 0.05/1, the condensation time of 3.5 h, and the amount of sodium hydroxide of 11 %, a phenolic lignin-furfural adhesive with good performance was obtained (solid content of 56.25 %, pH of 11.2, viscosity of 1 525 mPa·s, free furfural content of 0.04 %, free phenol content of 0.05 %, adhesive strength of 1.67 MPa). After the optimization of hexamethylenetetramine, the adhesive layer was evenly distributed and closely combined with the wood surface, and there were many effective adhesive nails, proving that the adhesive strength was effectively improved. The composite putty obtained from the mixture of phenolic lignin-furfural adhesive and eucalyptus powder can be used for gap filling and flatness control of plywood surface. It had the advantages of no formaldehyde, good compatibility with plywood, fast drying speed, good water resistance, good grinding property, high bonding strength. It provides technical support for the direct finishing of plywood and improving the gloss of the finish. [ABSTRACT FROM AUTHOR]

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Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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The gibbsite bauxite pretreated by low-temperature roasting, the effects of roasting temperature and time on the dehydration and decarbonization of gibbsite ore and the digestion performance of calcined alumina were systematically studied by means of XRF, XRD and SEM. The results show that the ore quality greatly reduces after roasting and the obvious cracks are observed on the ore surface with lamellar structures. The gibbsite phase decreases and gradually changes to the boehmite, while the goethite changes to the hematite. When the roasting temperature is 400℃ and the roasting time is 30min, the mass fraction of crystal water in the ore is 7.54%, the dehydration ratio is 62.52%, the mass fraction of carbon is down to 0.11%, and the decarbonization ratio is 85.73%. When the digestion temperature of calcined ore is 145℃, the digestion time is 30 min, the mass concentration of circulating mother liquor caustic soda is 170g/L, and the actual digestion ratio of alumina is 81.51%, which is higher than that of the raw ore. The digestion kinetics results of calcined ore show that the digestion process of alumina is mainly controlled by internal diffusion, and the apparent activation energy is 42.71kJ/mol. [ABSTRACT FROM AUTHOR]

The method of separation of chromate from high alkali medium by barium salt to get the intermediate product of barium chromate was proposed, and through the acid dissolution reduction method to get chromium hydroxide. Then, using the oxidability and acidity of hydrogen peroxide, it takes sodium hydroxide as a sodium source and accurately regulates the reaction conditions. The chromium hydroxide is directly oxidized to sodium chromate without by-products. The effects of reaction temperature, reaction time, liquid-solid ratio, stirring speed, quantity of hydrogen peroxide, and chromium alkali molar ratio have been studied, the reaction process was optimized by response surface method. The results showed that the optimal reaction alkali chromium molar ratio 2.15∶1（stoichiometric ratio）, liquid-solid ratio 3.9∶1 mL/g, theoretical multiple of hydrogen peroxide 1.86, temperature conditions were 88 ℃ and agitation speed of 300 r/min. Under this condition, the chromium oxidation rate can reach 99.56% for reaction 90 min. [ABSTRACT FROM AUTHOR]

In order to rapidly adsorb trace coexisting Pb and As ions in wastewater by modified kenaf core, the effects of acid -base modification, concentration of sodium carbonate and modification time on the adsorption performance were investigated ・ The results showed that compared w让h hydrochloric acid, citric acid and sodium hydroxide, sodium carbonate modified kenaf core had better adsorption both of Pb and As. The optimum modification conditions were: the solid-liquid ratio of kenaf core to 0. 1 mol/L sodium carbonate solution was 1: 80 g/mL, and the reaction was stirred at 400 i/min at room temperature (about 25 °C) for 30 min. The removal rate could reach 77. 7% and 21 ・ 5% respectively when 50 mL, 0. 1 mg/L Pb and As wastewater was treated by 0. 5 g sodium carbonate modified kenaf core, oscillating in the 25 °C constant temperature water bath at 200 r/min for 30 min. The adsorption process can be described by the pseudsecond order model, which indicates that it is chemical adsorption. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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The preserved egg, a well-known food in China, has become a key part of China’s egg industry after hundreds of years of development and improvement. After pickling, fresh duck eggs are subjected to thinning, solidification, color transformation, and maturation during preservation. The chemical principles of the four stages of preserved egg formation were illustrated by the following tests: duck egg white with sodium hydroxide, duck egg white with tannic acid, and L-arginine with glucose to simulate chemical changes by combining visualization and instrumental detection. The color change of magneson was used to verify that the pine flower contained magnesium hydroxide. Additionally, an interesting interactive program was designed to stimulate readers to explore chemistry and enhance their love of traditional Chinese cuisine. [ABSTRACT FROM AUTHOR]

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Cyclohexanol was selected as the extractant to concentrate fluosilicic acid, and the effects of comparison, temperature and time on the concentration of fluosilicic acid were studied, and the extractant was regenerated by alkali washing and vacuum distillation. The best extraction process is: the ratio of extractant to dilute fluorosilicic acid is 12∶1,the concentration of fluorosilicic acid is the best when the temperature is 60 ℃ and the time is 50 min. The results of the extraction agent regeneration experiment found that the concentration of sodium hydroxide in the alkaline washing process is proportional to the recovery of fluorine; the removal of water in the extraction agent is proportional to the vacuum degree during vacuum distillation. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Objective The CO2 absorption process under high gravity environment is simulated so as to provide guidance for the optimization of experimental process parameters. Methods An Aspen Plus calculation model for CO2 absorption using NaOH alkaline solution under high gravity was established, and the influence factors on the CO2 removal rate were investigated. Results While the high gravity reactor was equivalent to a conventional packed tower through the equivalent conversion method, the influence of sodium hydroxide mass fraction, solution feed rate and pressure on the CO2 removal rate were similar to that of the high gravity laboratory value, but the simulated value was only about 1/2 of the experimental value. The corrected simulation results were close to the experimental values, and the average deviation was only 0. 77%. Conclusions The established CO2 absorption model under high gravity environment is accurate and reliable, which can provide some directional guidance for subsequent experiments. [ABSTRACT FROM AUTHOR]

The synthesis of N, N'-l,4-bis( 4-methylphenyl) sulfonyl-liomopiperzine was studied with N-methylpyirolidone as solvent, NaOH as acid binding agent and 1,3-dichloropropane as cyclization reagent. The effects of reaction time, the molar ratio of reactants, reaction temperature, and the amount of sodium hydroxide on the yield of N,N'-1,4-bis(4-methylphenyl) sulfonyl-homopiperzine were investigated. The result showed that the order of effects was as follows: alkali amount > temperature > molar ratio of reactants. The yield could reach 81.93% under the conditions of 5 mmol N,N-bis(toluenesulfonyl)-1,2-ethylenediamine, 7.969 mmol 1,3-dichloropropane and 0.548 g sodium hydroxide,123 °C react 40 min. The kinetic analysis of the synthesis of N,N-1,4-bis(4-methylphenyl) sulfonyl-homopiperzine was carried out at 115, 125, 135 °C according to the second-order reaction mechanism, and the activation energy of this reaction was 76. 233 kJ/mol. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Basic Sciences Journal of Textile Universities / Fangzhi Gaoxiao Jichu Kexue Xuebao is the property of Basic Sciences Journal of Textile Universities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A rapid method for the determination of free acids in chloropalladium acid solution was developed by using an automatic potentiometric titration and composite glass electrode. The results show that the automatic potentiometric titration can accurately distinguish the end points of the reaction of free acid with sodium hydroxide and chloropalladium acid with sodium hydroxide, the maximum jump point of the first step EP1 is the target end point. The recovery of hydrochloric acid is between 85% and 110%, and the relative standard deviation (RSD) is less than 2%. The method is intuitionistic, rapid and accurate. It is suitable for the determination of free acid in chloropalladium acid solution. [ABSTRACT FROM AUTHOR]

BACKGROUND: The traditional alkaline hydrolysis diffusion separation acid -base titration method is used to determine the hydrolysable nitrogen in soil samples. Usually, a glass diffusion dish is used for alkaline hydrolysis diffusion separation. However, during sample pretreatment and alkaline hydrolysis diffusion separation, the operator often faces the following three problems. First, the solution in the inner chamber of the glass diffusion dish is very easily polluted by sodium hydroxide solution and alkaline glue solution. Second, ammonia leakage occurs easily between the glass diffusion dish and the cover, and it is often not possible to remedy when it is found. Third, the glass diffusion dish is bulky and fragile, and the experimental operation is inconvenient, all of which lead to the instability of measurement results due to inexperience of the operator. OBJECTIVES: To establish a new method for the determination of hydrolysable nitrogen in soil samples by alkaline hydrolysis diffusion separation acid-base titration based on polypropylene diffusion dish. METHODS: A polypropylene diffusion dish was used instead of a glass diffusion dish in the alkaline hydrolysis of hydrolysable nitrogen. The cleaning method and the sealing of the diffusion dish were improved. The addition amount of reducing agent and the concentration of sodium hydroxide solution ( 1. 8mol / L) were unified. The addition volume of sodium hydroxide solution was appropriately increased, and the concentration of hydrochloric acid standard solution was reduced. RESULTS: The absolute deviation of reference materials GBW07416a with the measured value of hydrolysable nitrogen <50mg / kg was 0. 2 - 1. 8mg / kg. The absolute deviation of reference materials GBW07415a, NSA- 1, NSA-4, NSA-5 and NSA-6 with the measured value of hydrolysable nitrogen of 50-200mg / kg was 0-4. 0mg / kg. The recovery rate of nitrate nitrogen converted to ammonium nitrogen by reducing agent was 89. 6%-96. 4%. The measured value of soil available reference materials was consistent with the standard value. CONCLUSIONS: The stability and accuracy of hydrolysable nitrogen determination are improved. The pollution in this method is significantly reduced, ammonia leakage is avoided, and the operation is convenient. The method meets the requirements for determining the content of hydrolysable nitrogen in soil samples. [ABSTRACT FROM AUTHOR]

In view of the problem that a large number of high salt and high COD wastewater are produced in the production of thiosemicarbazone, a new process for the production of thiosemicarbazone by ammonia discharge method is designed・ A large number of by-product ammonia gas produced in the preparation of thiosemicarbazone is discharged from the reaction system, ammonia water is prepared by ammonia absorption tower, and is applied to the neutralization process of the preparation of 2・amino-1,3,4・thiadiazole instead of sodium hydroxide solution, so as to realize the efficient recovery and utilization of by-product ammonia gas in the production process・ Amount of hydrochloric acid used is reduced by 84%, the content of NH4CI in wastewater is reduced by 86%, and the output of wastewater is reduced by 63% ・ The output of high salt and high COD wastewater is greatly reduced, the production cost is reduced, and cleaner production is achieved・ The optimum process conditions for preparing thiosemicarbazone were obtained through the contrast experiments of feed ratio, ammonia removal time, reflux time, the amount of isomerizing agent acetone and the recycling of reaction mother liquor. The molar ratio of ammonium thiocyanate to hydrazine hydrate is 1 ： 0.7, the ammonia removal time is 4 h, the reflux reaction time is 3 h, the amount of isomerization agent acetone is 7 kg, and the proportion of reaction mother liquor to water is 2 ： 1 ・ Through the optimization of the preparation process conditions such as the feed ratio, the amount of hydrochloric acid, the reaction time, and the type of alkali used in the neutralization reaction, the optimal process conditions for the preparation of 2-amino-l, 3,4-thiadiazole were obtained・ Thiosemicarbazone - formic acid is 1： 1.1, the amount of hydrochloric acid added is 80 L, and the reaction time is 5 h・ The pH of reaction solution was adjusted with ammonia water or ammonia gas instead of sodium hydroxide solution. Through green preparation process research, the yield and purity of thiosemicarbazone and 2-amino-1,3,4-thiadiazole were improved. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the problem of cotton fiber lacking UV resistance, a water-soluble UV absorber was prepared from o-nitroaniline and 2-naphthol-6 sodium sulfonate hydrate and acted on cotton fabric to endow cotton fabric with UV resistance. O-nitroaniline was diazotized and coupled with 2-naphthol-6 sodium sulfonate hydrate to form 2-naphthol-7 sulfoazo-o-nitrobenzene intermediate. Then intermediate was reduced by a certain amount of basic sodium hydrosulfite to form a water-soluble benzotriazole ultraviolet absorber. As azo reaction is a classical reaction, the best reduction conditions of intermediates were studied by single factor experiments. The results show that the optimal reduction conditions are as follows; the molar ratio of sodium hydroxide to intermediates is 0.4:1, the molar ratio of sodium hydroxide to intermediates is 1.1:1, the reaction temperature was 30 °C, the reaction time was 1 h. The molar ratio of hydrochloric acid to intermediate is 2:1. The results show that the UV protection factor of the finished cotton fabric can reach 58.77, the wrinkle recovery angle can reach 92°, the breaking strength can reach 226 N, and the air permeability can reach 2 567 L / (m² s). The UV absorber prepared in this study is water-soluble and improves the absorption performance of benzotriazole ultraviolet absorber, which has good application value. [ABSTRACT FROM AUTHOR]