有机胺热稳剂对环丁砜热稳定性的影响

芳烃生产中,抽提剂环丁砜在较高温度会发生劣化导致pH的下降,产生酸性物质,并影响抽提效果,随着劣化程度的加深对抽提设备的腐蚀也越加严重,也会影响芳烃产品的生产效率和质量。为解决这一问题,一般采用加入热稳剂的方法减缓环丁砜的劣化情况,增加芳烃抽提剂环丁砜的使用寿命。本文对环丁砜受热劣化的情况进行了考查,选用了三种不同有机胺化合物及其复配物作为减缓环丁砜劣化程度的热稳剂,利用检测热分解产生的SO_(2)量来衡量劣化程度和热稳效果。实验结果发现复配热稳剂效果最佳,其中以乙醇胺与不饱和多元胺A的复配比例在2:1,添加量在400mg/L时的热稳效果最好,热稳率超过最好单一热稳剂10%以上。

河北研制出新型PVC热稳剂

河北衡水桃城化工助剂有限责任公司会同有关科研院校联合攻关，近日成功开发出含铅量极低的新型PVC热稳定剂。

Development of a Thermal Fogger-specific Sedimentation Stabilizer

In order to solve the drifting away of thermal fog droplets during thermal spraying and the incompatibility between fog droplet carrier and conventional com- mercial agro-chemicals, the fog droplet carrier, surfactant, condensation nucleus ma- terial and antifreeze, dispersant, thickener and defoamer were screened and assem- bled to develop a thermal fog sedimentation stabilizer in this study, thereby provid- ing technical support for application and promotion of thermal spraying technology in pest and disease control in crops.

Synthesis and characterization of colored layered double hydroxides for thermal stabilizer

Colored layered double hydroxides （LDHs） can be synthesized by introducing colored cations such as Fe^3＋ and Cr^3 ＋, which call be used as thermal stabilizers for polyvinyl chloride （PVC）. The yellowish Mg/Fe and bluish Mg/Cr LDHs are prepared by the co-precipitation method. The results show that the MgsCr_ CO3 and Mg3Fe_ CO3 colored layered double hydroxides can stabilize PVC for more than 30 min under the thermal aging temperature of 180 ℃. The preparation can use cheap Mg（OH） 2 instead of MgCl2, which produces a much smaller amount of the by-product NH4Cl. It is known that NH4Cl is a cheap fertilizer that is difficult to sell; therefore, the preparation is much greener and more economic than the one using magnesium salt.

The origin of the extraordinary stability of mercury catalysts on the carbon support: the synergy effects between oxygen groups and defects revealed from a combined experimental and DFT study

Thermal stability of HgCl2 has a pivotal importance for the hydrochlorination reaction as the loss of mercuric compounds is toxic and detrimental to environment.Here we report a low-mercury catalyst which has durability over 10000 h for acetylene hydrochlorination under the industrial condition.The stability of the catalyst is carefully analyzed from a combined experimental and density functional theory study.The analysis shows that the extraordinary stability of mercury catalyst is resulted from the synergy effects between surface oxygen groups and defective edge sites.The binding energy of HgCl2 is increased to be higher than 130 kJ/mol when adsorption is at the edge site with a nearby oxygen group.Therefore,the present study revealed that the thermal stability problem of mercury-based catalyst can be solved by simply adjusting the surface chemistry of activated carbon.Furthermore,the reported catalyst has already been successfully applied in the commercialized production of vinyl chloride.

Synthesis and application of antimony pent(isooctyl thioglycollate)

A new type of thermal stabilizer, antimony pent（isooctyl thioglycollate）(Sb(SCH2COOC8H17)5), was synthesized by using antimony trioxide, isooctanol and thioglycolic acid in 2 steps. Firstly, antimony trioxide was oxidized into colloidal antimony peroxide. Then antimony peroxide and isooctyl thioglycollate reacted stoichiometrically for 2 h with the yield of 87%. This compound was used as thermal stabilizer for polyvinyl chloride（PVC）. The results show that the thermal stability time is 52min at 200℃ by heat-ageing oven test when adding 2.5% thermal stabilizer to PVC resin. Compared with antimony tris（isooctyl thiolycollate）, the initial thermal stability of antimony pent（isooctyl thioglycollate） is better than that of antimony tris（isooctyl thioglycollate）, while the long-term thermal stability time is shorter than that of antimony tris（isooctyl thioglycollate）. Meanwhile, the synergism of antimony pent（isooctyl thioglycollate） with calcium stearate was studied, indicating that when the mass ratio of antimony pent（isooctyl thioglycollate） to calcium stearate is （2∶1,） the thermal stability time of PVC is 58min.

Effect of phosphite and epoxy soybean oil on heat stability of poly （vinylchloride） composite stabilizers

The influences ofphosphite and epoxy soybean oil in combination with liquid calcium/zinc isocaprylates on the thermal stability of flexible poly （vinyl chloride） were studied. The stabilizing effect of poly （vinyl chloride） was evaluated by Congo red method, thermoaging test and Thermogravimetric-differential Scanning Calorimetry （TG-DSC）. The results showed that the addition of the phosphite or epoxy soybean oil improved the thermal stability of PVC with the calcium/zinc isocaprylates stabilizing system, especially epoxidied soybean oil exhibited a remarkable effect, and the synergism on PVC thermal stability for 3：2 phenyl dioctyl phosphite to epoxidized soybean oil weight ratio was acquired. Accordingly, the rapid mass loss in TG curve occured between 258.9 ℃ and 334.4 ℃, which corresponded to the enthalpy of the pyrogenation of 609.2 J/g. It was also found that the stabilized PVC of the best ratio gave better mechanical and processing properties.

Eco-friendly synthesis of high silica zeolite Y with choline as green and innocent structure-directing agent

Zeolite synthesis in contemporary chemical industries is predominantly conducted using organic structure‐directing agents(OSDAs),which are chronically hazardous to humans and the environment.It is a growing trend to develop an eco‐friendly and nuisanceless OSDA for zeolite synthesis.Herein,choline is employed as a non‐toxic and green OSDA to synthesize high silica Y zeolite with SiO2/Al2O3 ratios of 6.5–6.8.The prepared Y zeolite samples exhibited outstanding(hydro)thermal stability at ultrahigh temperature owing to the higher SiO2/Al2O3 ratio.The XRF,SEM,29Si‐NMR and 13Na+results suggested that choline plays a structure‐directing role in the synthesis of Y zeolite,while the feed molar fraction of Na+is a crucial determinant for the framework SiO2/Al2O3 ratio and the crystal morphology.

Stability of [BMIM]HSO_4 for using as additive during zinc electrowinning from acidic sulfate solution

The stability of ionic liquid additive 1-butyl-3-methylimidazolium hydrogen sulfate （[BMIM]HSO4） during zinc electrowinning from acidic sulfate solution was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. Compared with the traditional industrial additives, gelatine and gum arabic, [BMIM]HSO4 has more excellent chemical and thermal stabilities. The inhibition effects of gelatine and gum arabic on the zinc electrocrystallization are observed to markedly weaken due to their part degradation after 12 h longtime successive electrolysis and high temperature （90 ℃） treatments. In contrast, the activity of [BMIM]HSO4 is practically unaffected after 24 h longtime successive electrolysis and high temperature treatments. These results are corroborated with the corresponding morphological analysis of the cathodic deposits.

Rational construction of thermally stable single atom catalysts:From atomic structure to practical applications

As a new frontier in catalysis field,single-atom catalysts(SACs)hold unique electronic structure and high atom utilization,which have displayed unprecedented activity and selectivity toward a wide range of catalytic reactions.However,many reported SACs are susceptible to Ostwald ripening process in high temperature environment or long-term catalytic application,which will cause sintering and deactivation.This is due to the weak interaction between the metal atom and supports.The regeneration and recycling of deactivated catalysts will greatly increase the time and economic cost of industrial production.Therefore,it is necessary to develop SACs with excellent thermal stability to meet the industrial demands.Here,we discuss the fundamental comprehension of the stability of thermally stable SACs obtained from different synthesis methods.The influences of the speciation of metal centers and coordination environments on thermal stability are summarized.The importance of using novel in situ and operando characterizations to reveal dynamic structural evolution under synthesis and reaction conditions and to identify active sites of thermally stable SACs is highlighted.The mechanistic understanding of the unique role of thermally stable SACs in thermocatalytic application is also discussed.At last,a brief perspective on the remaining challenges and future directions of thermally stable SACs is presented.

Highly Active and Stable Ni_2P/SiO_2 Catalyst for Hydrogenation of C_9 Petroleum Resin

Catalytic hydrogenation is an appropriate method for the improvement of C9 petroleum resin（C9PR） quality. In this study, the Ni2P/SiO2（containing 10% of Ni） catalyst prepared by the temperature-programmed reduction（TPR） method was used for hydrogenation of C9 petroleum resins. The effect of reaction conditions on catalytic performance was studied, and the results showed that the optimum reaction temperature, pressure and liquid hourly space velocity（LHSV） was 250 ℃, 6.0 MPa, and 1.0 h-1, respectively. The bromine numbers of hydrogenated products were maintained at low values（250 mg Br/100g） within 300h, showing the high activity and stability of Ni2P/SiO2 catalyst. The fresh and spent catalysts were characterized by X-ray diffraction（XRD）, BET surface area（BET） analysis, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, Fourier transform infrared（FTIR） pyridine adsorption, and X-ray photoelectron spectroscopy（XPS）. Compared with the traditional sulfurated-Ni W catalysts, Ni2P possessed globe-like structure instead of layered structure like the active phase of Ni WS, thereof exposing more active sites, which were responsible for the high activity of Ni2P/SiO2 catalyst. The stability of Ni2P/SiO2 catalyst was probably attributed to its high sulfur tolerance, antisintering, anti-coking and carbon-resistance ability. These properties might be further ascribed to the special Ni-P-S surface phase, high thermal stability of Ni2P nanoparticles and weak surface acidity for the Ni2P/SiO2 catalyst.

Evaluation of Efficacy of Stabilizers on the Thermostability of Live Attenuated Thermo-adapted Peste des petits ruminants Vaccines

In this study, thermo-adapted （Ta） PPR vaccines were assessed for their stability at 25, 37, 40, 42 and 45℃ in lyophilized form using two extrinsic stabilizers {lactalbumin hydrolysate-sucrose （LS） and stabilizer E} and in reconstituted form with the diluents （1 mol/L MgSO4 or 0.85% NaC1）. The lyophilized vaccines showed an expiry period of 24-26 days at 25℃, 7-8 days at 37℃ and 3-4 days at 40℃. LS stabilizer was superior at 42℃ with a shelf-life of 44 h, whereas in stabilizer E, a 40 h shelf-life with a comparable half-life was observed. At 45 ℃, the half-life in stabilizer E was better than LS and lasted for 1 day. Furthermore, the reconstituted vaccine maintained the titre for 48 h both at 4℃ and 25℃ and for 24-30 h at 37℃. As both the stabilizers performed equally well with regard to shelf-life and half-life, the present study suggests LS as stabilizer as a choice for lyophilization with 0.85% NaCldiluent, because it has better performance at higher temperature. These Ta vaccines can be used as alternatives to existing vaccines for the control of the disease in tropical countries as they are effective in avoiding vaccination failure due to the breakdown in cold-chain maintenance, as this vaccine is considerably more stable at ambient temperatures.

Study of the Stability of Beef Tallow at High Temperatures and Comparison with Other Fatty Materials

Beef tallow is a byproduct of the slaughter industry. As a consequence, meat producer countries obtain a high amount of this low value-added fatty material. In Uruguay, it is generally used for food purposes or for biodiesel production. Globally, around half of the beef tallow produced worldwide is used for the manufacturing of food. To the best of our knowledge there are no published studies concerning the stability of beef tallow when exposed to high temperatures. The aim of this work was to study some Uruguayan beef tallow brands and compare its stability with that of the most frequently used frying oils in Uruguay （sunflower high oleic, rice bran and sunflower oil） to assess its suitability for frying. Stability was assessed by the oxidative stability index and thermoxidation in absence of food. Even though beef tallow＇s inherent stability indicated that it should be highly stable to oxidation, the majority of the analyzed samples exhibited a similar or lower stability than sunflower high oleic. This might be explained by a different composition in pro-oxidants and/or antioxidants between the beef tallows and the oils. According to the thermoxidation assays, which are carried out in similar conditions to those of a frying process, three of the beef tallow samples, sunflower high oleic and rice bran oil would be similarly suitable for frying, while sunflower oil and the other two samples of beef tallow evidenced a lower thermoxidative stability, thus not being recommended for this use.

Research Progress of Palladium Catalysts for Methane Combustion

Recent research progress and development of the palladium catalysts for methane combustion are described in this study.The influence of active species,precursor,solvent,preparation methodologies,support and dopant on the catalytic activity and thermal stability of the palladium catalysts was discussed.Results of deactivation and poisoning of palladium catalysts were analyzed.Furthermore,possible kinetic models and reaction mechanism were indicated for Pd catalysts.

Synthesis of texture-excellent mesoporous alumina using PEG1000 as structure-directing agent

By varying concentration of PEG1000 as a structure-directing agent,mesoporous alumina with excellent textural properties was synthesized.The prepared mesoporous alumina displays high thermal stability,as shown by its textural properties at different calcination temperatures of 600-850 °C.Characterization by SEM and TEM revealed that the added PEG surfactant induced the formation of petal-like alumina.XRD results clarified that all samples were amorphous and their peaks were around the peaks of γ-alumina.N_2 adsorption-desorption analysis showed that the prepared mesoporous alumina,if with PEG1000 in hydrolysis of aluminum isopropoxide,had excellent textural properties with large specific surface area,high pore volume and suitable pore size.The petal-like structure existing in the alumina samples improved their textural parameters,and the role and influential mechanism of PEG1000 were analyzed.

Getting and X-Ray Diffraction Analysis of the Microsphere Magnetic Catalyst of the Thorium-Uranium Catalyst for Fischer-Tropsch Synthesis

We first obtained by impregnating of the microsphere magnetic catalyst with salts of Thorium and of Uranium and examined the X-ray thorium-uranium catalyst for Fischer-Tropsch synthesis. Introduction in catalyst additive thorium and uranium ions and manganese improves the thermal stability of the magnetic microsphere catalyst.

Synthesis and Application of a Zeolite-containing Composite Material Made from Spent FCC Catalyst

Novel composite material with a wide pore distribution was synthesized by an in situ technique using spent FCC catalyst as raw material. The characterization results indicated that the composite material contained 56.7% of zeolite Y and exhibited a much larger specific surface area and pore volume as well as strong hydrothermal stability. Fluid catalytic cracking(FCC) catalyst was prepared based on the composite material. The results indicated that the as-prepared catalyst possessed a unique pore structure that was advantageous to the diffusion-controlled reactions. In addition, the attrition resistance, activity and hydrothermal stability of the studied catalyst were superior to those of the reference catalyst. The catalyst also exhibited excellent nickel and vanadium passivation performance, strong bottoms upgrading selectivity, and better gasoline and coke selectivity. In comparison to the reference catalyst, the yields of the gasoline and light oil increased by 1.61 and 1.31 percentage points, respectively, and the coke yield decreased by 0.22 percentage points, and the olefin content in the produced gasoline reduced by 2.51 percentage points, with the research octane number increased by 0.7 unit.

Evaluation on the Thermal Stability and Hazards Behaviors of ADVN Using Green Thermal Analysis Approach

ADVN （2,2＇-Azobis （2,4-dimethyl） valeronitrile）, a free radical initiator, is widely applied for the polymerization reaction of polymers in the chemical industries. When ADVN releases free radical during the decomposition process, it can accompany abundant heat and huge pressure to increase the possibility of thermal runaway and hazard, causing unacceptable thermal explosion or fire accidents. To develop an inherently safer process for ADVN, the thermal stability parameters of ADVN were obtained to investigate thermal decomposition characteristics using a DSC （differential scanning calorimetry） and TG （thermogravimetry）. We used various kinetic models to completely depict the kinetic behavior and determine the thermal safety parameters for ADVN. The green thermal analysis approach could be used to substitute for complicated procedures and large-scale experiments of traditional thermal analysis methods, avoiding environmental pollution and energy depletion.

Solvothermal Route to Prepare the Metastable Phase 3c-Fe_7S_8 with Hexagonal Platelet Morphology

The metastable phase 3c-Fe7S8 with the hexagonal platelet morphology has been prepared by using solvothermal route. The product was characterized by means of X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS). The experiment results show that the as-prepared Fe7S8 is a metastable phase with the hexagonal platelet morphology.

Highly active CeO_2 hollow-shell spheres with Al doping

Metal oxide hollow structures are of great inter- est in many current and emerging areas of technology. This paper presents a facile and controlled protocol for the syn- thesis of Al-doped CeO2 hollow-shell spheres （CHS）, where the dopant confers enhanced stability and activity to the ma- terial. These Al-doped CeO2 hollow-shell spheres （ACHS） possess a controllable shell number of up to three, where the sizes of the exterior, middle, and interior spheres were about 250-100 nm,150-50 nm, and 40-10 nm, respectively, and the average shell thickness was -15 nm. The thermal stability of the ACHS structure was enhanced by the homogeneous in- corporation of AI atoms, and more active oxygen species were present compared with those in the non-doped congener. Au NPs supported on ACHS （Au/ACHS） showed superior cat- alytic performance for the reduction of p-nitrophenol. For the same Au NP content, the reaction rate constant （k） of the Au/ACHS was nearly twice that of the non-doped Au/CHS, indicating that AI doping is promising for improving the per- formance of inert or unstable oxides as catalyst supports.