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Plant pigments are natural organic compounds found in plant cells. They impart vibrant colors to plants and play essential roles in processes such as photosynthesis and other physiological reactions. This article provides an overview of the classification and chemical molecular structures of plant pigments, as well as an introduction to their basic coloration mechanisms. It guides individuals in understanding the colorful world at the molecular level and emphasizes the intrinsic connection between organic chemistry and plant physiological activities. [ABSTRACT FROM AUTHOR]

In response to the difficulties students face in understanding abstract structures and complex reactions in organic chemistry teaching, this study explores the combination of virtual reality (VR) technology, specifically the chemistry metaverse, with organic chemistry courses. This approach allows students to learn about the molecular structure, spatial conformation, and reaction mechanisms of organic compounds through interactive learning. The integration of VR technology not only improves the quality of organic chemistry teaching, but also enhances students' interest in learning, as well as their hands-on and innovative abilities. Additionally, this research analyzes the challenges and innovations in applying VR technology to organic chemistry teaching. By addressing the gap in the use of VR technology in organic chemistry teaching and research in domestic universities, this study demonstrates its significant potential. [ABSTRACT FROM AUTHOR]

Triazolopyrimidine compounds containing carboxyl and thioether groups were synthesized using 3-amino5-mercapto-1,2,4-triazole, benzyl bromide, and diethyl ethoxymethylenemalonate (EMME) as starting materials. The synthesis involved nucleophilic substitution, cyclization, and hydrolysis reactions. The resulting products were characterized and analyzed for their structures. The experiment included techniques such as heating reflux, TLC (thinlayer chromatography) detection, filtration, and recrystallization, which aimed to enhance students' skills in multi-step organic compound synthesis and spectral analysis. Triazolopyrimidine compounds are widely found in natural products and pharmaceuticals. The synthesis of these compounds not only provides insight into societal demands but also integrates cutting-edge research and theoretical knowledge taught in the classroom, thereby improving the quality of experimental teaching and achieving excellent educational outcomes. [ABSTRACT FROM AUTHOR]

A two-step synthetic experiment to produce paracetamol from 4-hydroxyacetophenone was designed for undergraduate organic chemistry courses. The experiment begins with the condensation of 4-hydroxyacetophenone with hydroxylamine to form 4-hydroxyacetophenone oxime. This oxime then undergoes a Beckmann rearrangement catalyzed by cyanuric chloride to yield paracetamol. The experiment incorporates several essential organic laboratory techniques, such as reflux, extraction, drying, filtration, rotary evaporation, thin-layer chromatography, and column chromatography, providing students with comprehensive training in organic synthesis. By synthesizing a compound of significant medical and economic value, the experiment demonstrates practical applications of organic synthesis, thereby enhancing student interest in organic chemistry. Additionally, the use of a small molecule organic catalyst for the Beckmann rearrangement deepens students’ understanding of the principles of organic catalysis and the mechanism of the Beckmann rearrangement. [ABSTRACT FROM AUTHOR]

This article presents a comprehensive organic chemistry experiment in which salicylaldehyde, phenylboronic acid, and aromatic amines are employed as the substrates. The selective synthesis of diarylmethyl aniline and triarylmethane could be achieved through the control of substituents. The structure of the product is characterized by ¹H NMR and 13C NMR. This experiment combines theoretical knowledge to inspire students to think about mechanisms, helps them broaden their knowledge horizons, and establishes the concept of "green chemistry" and environmental awareness. [ABSTRACT FROM AUTHOR]

In order to improve the teaching quality of Organic Chemistry courses in normal universities, this study analyzes the problems in the construction of this course based on the principles of “student-centered, outcomeoriented, and continuous improvement”. The analysis is conducted from both the perspectives of student learning and teacher instruction. Moreover, targeted solutions are proposed, and the implementation of the “128” strategy for course construction is described. As a result, a distinctive and highly effective teaching system for Organic Chemistry courses has been established, leading to significant achievements in curriculum development. [ABSTRACT FROM AUTHOR]

Chlorinated polyethylene rubber (CM)/nitrile rubber (NBR) blend vulcanizates were prepared by mechanical blending method with CM and NBR as main raw materials, the cross-linking density of CM phase in CM/NBR blend vulcanizate and the stress-strain relationship of CM/NBR blend vulcaizate were characterized by regulating the dose of vulcanization system of CM phase in CM/NBR blend combined with the means of equilibrium swelling method, testing mechanical properties and theoretical calculation, and the influence of the change of cross-linking density of CM phase on matching degree of the modulus of two phase in CM/NBR blend vulcanizate and mechanical properties of CM/NBR blend vulcanizate were studied. The results showed that the change of the modulus of CM/NBR blend vulcanizate caused by the increase in cross-linking density of CM phase was greater than that of its own; with the increase of modulus, the influence of the change of cross-linking density of CM phase on the modulus of CM/NBR blend vulcanizate increased; by comparing the stress-strain relationship of CM phase and NBR phase in CM/NBR blend vulcanizate and the change of mechanical properties of CM/NBR blend vulcanizate, it was proved that the decrease of the cross-linking density of CM phase was a process of the gradual matching of the modulus of the two phase; compared with the error of the measured stress-strain relation, that of the stress-strain relationship predicted by fitting model was relatively smaller, which indicated that fitting model had certain applicability.

The ash content of rubber was determined by thermogravimetric analysis (TGA) and the effects of sample amount, sample representativeness, heating rate, combustion temperature and combustion atmosphere on the test results were studied and the repeatability and reproducibility of the method were determined. The results showed that the optimal conditions of TGA were sample mass between 10 mg and 20 mg, heating rate of 20 ℃/min or 30 ℃/min, combustion temperature for raw rubber and compounded rubber (or vulcanized rubber) of 550 ℃ and 650 ℃, respectively. The repeatability and reproducibility of TGA were all good. When ash mass fraction of 4 types of different rubbers were from 0.29% to 5.12%, the repeatability within laboratory was from 0.110% to 0.303%, and the reproducibility between laboratories was from 0.283% to 0.676%.

With thermoplastic polyurethane (TPU) limit spring extruder head as the research object, the relevant material parameters of the constitutive equation of raw TPU were obtained by the rheological property test. Numerical simulation of the flow process of TPU in the extrusion runner was carried out based on the software Polyflow, and in the meanwhile, a second-order regression model of standard deviation of velocity (Sd) at the exit of the forming section was established by response surface method, and the influence law of extrusion runner structure on the melt flow uniformity of TPU was explored. The results showed that after optimization the structure parameters of extrusion runner were as follows: the length of the forming section of 165 mm, the expansion angle of 25°, and the number of diverter shuttles of 6. After optimization the predicted value of Sd at the exit of the forming section of extrusion runner was 0.531 m/s and was only 0.188% different from the actual value of Sd(0.532 m/s), which indicated that the model was more accurate, and the model could be used for the prediction and optimization of the structure parameters of extrusion runner.

Screw pump stator material was prepared with hydrogenated nitrile rubber as raw material, and the chemical aging damage of the screw pump stator material in different crude oil environment temperatures was studied by simulating real oil production environment and using a microscope and attenuated total reflection Fourier transform infrared spectroscopy. In addition, the chemical damage mechanism of the screw pump stator material in crude oil environment was explored. The results showed that the temperature of the crude oil and aging time had an important influence on the chemical aging damage of the screw pump stator material, and when the aging time was same, the mass change rate of the screw pump stator material increased with the increase in crude oil temperature, while at the same aging temperature, the mass change rate of the screw pump stator material increased with the prolongation of aging time and the increase rate of of mass change rate tended to slow down. The chemical damage mechanism of the screw pump stator material in the crude oil environment of 25 ℃ was mainly the fracture of molecular chains and the oxidation cross-linking reaction of carbon chains; in the crude oil environment of 60 ℃, the chemical damage mechanism included primarily the fracture of molecular chains, the oxidation cross-linking of carbon chains and the oxidation cross-linking reaction of nitrile groups; while in the crude oil environment of 100 ℃, the chemical damage mechanism consisted mainly of the fracture of molecular chains, the oxidation cross-linking reaction of carbon chains, the oxidation cross-linking reaction of nitrile groups and the cross-linking reaction between nitrile groups resulted from high temperature.

Genetic algorithm (GA) and particle swarm optimization (PSO) were used to optimize the back propagation（BP） neural network to establish the prediction model of Mooney viscosity of ethylene-propylene-diene monomer (EPDM) compound, and the error of the prediction results was compared and analyzed. The results showed that the predicted va-lues of the BP neural network model optimized by the two algorithms all maintained a high degree of fit and correlation with the measured values. Compared with the single BP neural network, the accuracy of the GA-BP neural network prediction model increased by 58.9% and the accuracy of the PSO-BP model increased by 3.57%, which indicated that the prediction accuracy of the prediction model optimized by the two algorithms, especially the BP neural network prediction model optimized by GA, improved significantly Mooney viscosity of EPDM compound.

Isobutylene polymerization was studied with the rare-earth metal scandium cationic complexes as catalysts and molecular weight and its distribution, and glass transition temperature of polyisobutylene were investigated by screening the catalyst system, adjusting the ratio of monomer to catalyst and regulating the reaction temperature and time. The results showed that the constrained-geometry-configuration scandium dialkyl catalyst which had relatively smaller steric hindrance had the highest catalytic activity for isobutylene polymerization among 5 kinds of rare-earth metal scandium cationic catalysts. The higher mole ratio of monomer isobutylene to catalyst was, the higher number-average relative molecular weight the resulting polymer had. The lower reaction temperature was, the higher numbe-average relative molecular weight of the polymer was, however, when the reaction temperature was below -60 ℃, the number-average relative molecular weight of the polymer decreased significantly. The reaction time had little effect on the change of the number-average relative molecular weight of the polymer. In addition, the polymerization reaction temperature and time had no significant effect on the glass transition temperature of polyisobutylene.

"Molecular weight and its distribution, molecular structure composition, curing characteristics, Mooney viscosity, physical and mechanical property, thermal-oxidative aging resistance, low temperature performance and catalyst residual amount of similar brand hydrogenated nitrile rubber (HNBR) products from Zannan SciTech Co Ltd and Zeon Corporation of Japan were mainly compared. The results showed that molecular weight and its distribution, molecular structure composition, Mooney viscosity of raw rubber, scorch time of compound, thermal-oxidative aging resistance and low temperature performance of HNBR ZN 35156 from Zannan SciTech Co Ltd were generally equivalent to those of Zetpol 2010 L from Zeon Corporation, and compared with Zetpol 2010 L, ZN 35156 raw rubber had somewhat lower saturation degree, and ZN 35156 compound had a little faster curing rate and slightly poorer processing performance, while ZN 35156 vulcanizate had slightly superior physical and mechanical properties such as hardness and tensile strength; molecular weight and its distribution, molecular structure composition, Mooney viscosity of raw rubber, scorch time of compound and thermal-oxidative aging resistance of HNBR ZN 35158 from Zannan SciTech Co Ltd were basically similar to those of Zetpol 2010 from Zeon Corporation, and compared with Zetpol 2010, bound acrylonitrile content of ZN 35158 raw rubber was greater, ZN 35158 compound had a little faster curing rate and slightly poorer processing performance, and ZN 35158 vulcanizate had slightly poorer low temperature performance, while ZN 35158 vulcanizate had slightly superior physical and mechanical properties such as hardness and tensile strength; hydrogenation catalysts of Zannan SciTech Co Ltd and Zeon Corporation were ruthenium-based catalyst and palladium-based catalysts, respectively, and catalyst residual amounts in HNBR products of Zannan SciTech Co Ltd were re-latively less. "

The volatile content in nitrile rubber was measured by halogen moisture meter and compared with the results obtained by the hot-roll method. The influence of different measurement conditions on the measured results of the halogen moisture meter was investigated. The results showed that using the halogen moisture meter, the volatile content in nitrile rubber raw rubber could be measured by both the preset drying time method and preset mass loss method. Under suitable conditions such as sample mass of 3 g, drying temperature of 110 ℃, preset heating time of 8 min, or preset mass loss of 1/140 mg/s, the measured results were consistent with the hot-roll method. This method reduced measure time, was easy to operate, and could be used to guide quickly actual production.

Based on the piezoresistive effect of nano conductive rubber, conductive silicone rubber composite pressure sensor was prepared using the matrix material silicone rubber, nano superconductive carbon black, silk fiber fabric, interdigital electrode, buffer polymer material and encapsulation mold by processes such as internal mixing, open mixing, vulcanization and encapsulating, and the conductive silicone rubber composite material with the optimal piezoresistive characteristics was prepared by optimizing the content of conductive filler in the silicone rubber matrix. Finally, the application performance of encapsulated pressure sensor on bridge support model was explored. The results showed that when mass faction of nano superconductive carbon black ■ was 6.11%, the conductive silicone rubber composite material reached the penetration threshold point and had the best piezoresistive characteristics; the conductive sensing composite material obtained by implanting silk fiber fabric into conductive silicone rubber was then combined with the flexible interdigital single-layer electrode and encapsulated to generate the pressure sensor with increased range, sensitive detection, and enhanced toughness; the pressure sensor had a good linear relationship between the pressure signal and the electrical signal, and could achieve pressure detection within the range of 0 to 40 MPa. In addition, the measured value of the pressure sensor in the bridge support model test were highly consistent with the theoretical value.

Zinc oxide/melamine hypophosphate (MHS)/butyl tape premix (BTP) flame-retardant composites were prepared by mixing MHS, zinc oxide and BTP using mechanical blending method and the synergistic flame retardant effect between zinc oxide and MHS was investigated. The combustion performance and thermal stability of zinc oxide/MHS/BTP composites were studied by scanning electron microscope, limited oxygen index, cone calorimetry and thermogravimetric analysis, and the effect of zinc oxide on the adhesive performance of zinc oxide/MHS/BTP composites was studied by persistent adhesion and peel strength test. The results showed that the addition of zinc oxide could adjust the carbon formation and foaming process of the MHS/BTP composite and result in the generation of a complete gas chamber structure. The limited oxygen index of the composite increased from 28.5% to 33.0%, the vertical combustion grade of UL-94 increased from V-1 to V-0, the peak of heat release rate of the MHS/BTP flame-retardant composite could decrease by 66.7% at most, the total heat release decreased by 22.0%, the peak of smoke release rate decreased by 67.3% and the total smoke release decreased by 58.5%. The mass fraction of carbon residue of the MHS/BTP flame retardant composite increased from 25.58% to 40.41% and the maximum thermal decomposition temperature increased from 344.96 °C to 394.91 °C. The addition of zinc oxide would lead to a slight reduction of persistent adhesion and peel strength of the MHS/BTP flame retardant composite.

The application of neodymium based cis-1,4-polybutadiene rubber (Nd-BR) BR 9101 N in the formula of support compound of run-flat tire was studied, and compared with those of foreign same type product Nd-BR CB 24. The results showed that Nd-BR BR 9101 N could meet the requirements for incoming inspection of Nd-BR raw material, and the basic compounding performance could be met. When Nd-BR BR 9101 N was used in the formula of support compound of run-flat tire to replace Nd-BR CB 24 with the same amount, Mooney viscosity, scorch time and curing characteristics of the former compound, and physical and mechanical property of Nd-BR BR 9101 N vulcanizate before and after aging were basically the same to those of the latter, and the aging performance of the former improved, whereas the compression fatigue temperature rise and compression set all reduced compared with those of the latter. The high-speed durability of finished tire made from Nd-BR BR 9101 N was good and could meet the product design requirements and exceeded the national standard regulations, which were basically equivalent to those of the existing production tire, in addition, the strength performance and zero-pressure durability of finished tire made from Nd-BR BR 9101 N improved compared with those of the existing production tire.

Silica/solution-polymerized butadiene-styrene rubber (SSBR)/natural rubber (NR) compo-sites were prepared by mechanical mixing method with silane coupling agent, bis[3-(triethoxysilyl)propyl]tetrasulfide (Si 69) and 3-mercaptopropyl-ethyoxyl-di(tridecyl-pentamethoxy)-silane (Si 747), as modifier and the effect of types and addtion amounts of silane coupling agent on the microstructure, curing characteristics, processing performance, physical and mechanical performance, dynamic mechanical properties, tire performance, and the relationship between structure and performance of the composite. The results showed that compared with the composite just only modified by Si 69, the incorporation of Si 747 resulted in the scorch time and optimum curing time of the composite shorten signi-ficantly, and the curing rate improved gradually with the increase in the addition amount of Si 747; the synergistic modification of Si 69 and Si 747 made the physical and mechanical properties, tensile strength, resilience and modulus at 300% of the composite all reduced; when the addition amount of Si 747 increased, the apparent activation energy which was used to characterize the temperature dependence of storage modulus of the composite reduced gradually; the dispersion of silica in the composite improved significantly after the addition of Si 747; the loss factor (tan δ) of the composite modified by Si 747 alone at 0 ℃ increased significantly and tan δ at 60 ℃ decreased significantly; the rolling resistance of the tire improved gradually with the increase in the addition amount of Si 747.

Micro-nano rubber asphalt was prepared by high-temperature and high-speed shearing with micro-nano degraded rubber powder as raw material, and the micromorphology of micro-nano degraded rubber powder and miscible process of micro-nano rubber rubber and substrate asphalt were investigated by scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectrometer, and the road performance of micro-nano rubber asphalt mixture including water stability, temperature stability and cracking failure resistance were studied by the design of asphalt aggregate ratio. In addition, the application effect of micro-nano rubber asphalt mixture in practical road engineering was further evaluated. The results showed that mass fraction of sol in degraded rubber in which the size of dissociated carbon black was about 200 nm reached 65.7%, and the interaction of sulfur cross-linked bond between degraded rubber and asphalt appeared during the miscible process; the micro-nano rubber asphalt mixture showed excellent water stability, high- and low-temperature stability and cracking failure resistance; the key technical indexes of the upper layer and the lower layer in full-depth rubber asphalt pavement of test section of Jiuquan-Jiayuguan ring expressway prepared by using micro-nano rubber asphalt mixture in Gansu province all complied with the specifications and design requirements.

Perfluoropolyether(PFPE)-based elastomers were new elastomers with extremely low glass transition temperature and excellent resistance to polar solvents. The structure and molecular weight of PFPE, the main raw material for preparing PFPE-based elastomers, were briefly introduced. The structures, synthesis methods and properties of three typical elastomers, including PFPE elastomer containing triazine ring, PFPE silicone elastomer and PFPE polyurethane elastomer, were summarized with 26 references. Finally, the development direction and market prospect of PFPE-based elastomers were prospected.

Using Na2EDTA solution as titrant, copper ion-selective electrode as indicator electrode, Ag/AgCl electrode as reference electrode, zinc ion content in zinc-containing curing activator was determined by potentiometric titration. The results showed that the addition of copper sulfate solution could increase the titration-jump of zinc ion titration curve and copper ion-selective electrode was sensitive in buffer system with pH value 10. The contents and recovery rates of zinc ions in two kinds of zinc-containing curing activators were determined by potentiometric titration and compared with atomic emission spectrometry. The results showed that the recovery rates of zinc ions in the two kinds of curing activators were 100.13% and 99.32% respectively, and there was no significant difference in accuracy and precision between the two methods. Content of zinc ion in standard solution was determined by potentiometric titration method and verified statistically. The results showed that there was no significant difference between the test value and standard value, indicating that using potentiometric titration method to determine the zinc content in the zinc-containing curing activator was feasible and effective. At the same time, the contents of zinc ion in mixed rubbers were determined, which were similar to the theoretical calculation value. Therefore, the method was also suitable for the determination of zinc ion content in mixed rubber.

The sequence structure, microstructure, molecular weight, processing performance, as well as low temperature resistance and compression permanent set of nitrile rubber (NBR) 1906 produced by Lanzhou Petrochemical Company were investiga-ted, and comparative analysized with similar products such as NBR 1965 produced by Zhenjiang Nandi Chemical Co Ltd (referred to as Nandi) and Nanjing Jinpu Insa Synthetic Rubber Co Ltd (referred to as Insa). The results showed that the acrylonitrile structural units of the three products were all randomly distributed, with NBR 1906 having a slightly lower BBB sequence structure content and slightly poorer flexibility. Molecular weight and its distribution of NBR 1906 were basically equivalent to the compared products, with a mass fraction of trans-1,4-unit about 4% higher and a mass fraction of cis-1,4-unit about 33% lower, but slightly better processing performance. The flat vulcanization period of NBR 1906 was comparable to that of Nandi NBR 1965, superior to that of Insa products, and there was no vulcanization reversion phenomenon. Tensile strength of NBR 1906 was about 9% higher than that of Insa NBR 1965, but about 5% lower than that of Nandi pro-duct. The crosslinking density and compression permanent set were at the same level as the comparison products, but the compression cold resistance coefficient below -40 ℃ was slightly inferior to that of the comparison products.

Three types of metal oxide, magnesium oxide(MgO), zinc oxide(ZnO) and aluminium oxide(Al2O3), were added into carboxylated nitrile rubber (XNBR) to prepared XNBR/metal oxide composites, the properties of which, such as interactions between metal ions and carboxyl groups, curing characteristics of the compounds, dynamic mechanical properties of the valcanizates, micromorphology, mechanical pro-perties and the modulus-temperature relationship of the composites, were investigated thoroughly. The results showed the formation of ionic bonds between XNBR and metal oxide was close to the alkalinity of metal oxide. The metal ion with high charge number, small ionic radius and high electronegativity was benefit to the improvement in mechanical properties of composites under high temperature.

Molecular weight and its distribution, gel content, nitrogen and phosphorus content, wet strength, Mooney viscosity, mechanical properties and aging resistance of three kinds of domestic raw natural rubber were compared with those of imported ribbed smoked sheet. The results showed that among the four kinds of natural rubber, the imported ribbed smoked sheet had the highest molecular weight with a narrower distribution, the highest nitrogen content, moderate phosphorus content and gel content, the best wet strength, the highest Mooney viscosity, and better tensile properties, but the highest compression fatigue heat generation; The product of Chinese Academy of Tropical Agricultural Sciences had moderate molecular weight and its distribution, the highest gel content, better wet strength, the lowest Mooney viscosity, the largest elongation at break and tear strength, and the best aging resistance; The product of Hainan Natural Rubber Industry Group Co Ltd had the lowest molecular weight with a narrower distribution, lower nitrogen content, the highest phosphorus content, poor wet strength, and good aging resistance, but the shortest scorch time. The product of Yunnan Natural Rubber Industry Group Co Ltd had higher molecular weight with the widest distribution, the lowest gel content and nitrogen and phosphorus content, poor wet strength, and the worst aging resistance, but the longest scorch time and the lowest compression fatigue heat generation.

A temperature-sensitive trans-1,4-polyisoprene (TPI)/natural rubber (NR) blending vulcanizate was prepared by controlling the ratio of TPI to NR. The results showed that the addition of NR reduced the X-ray diffraction peak intensity, crystallization enthalpy, and crystallinity of the blends. As the amount of NR increased, tensile strength of the TPI/NR vulcanizate decreased, while elongation at break increased, and the overall trend of particle dispersion on the fracture surface showed an increasing tendency. NR and TPI exhibited good compatibility, resulting in uniform dispersion of filler networks in the blends, with both storage modulus and loss factor varying with the amount of NR used. Blends of different ratios exhibited low-temperature setting and high-temperature rebound effects under stress. The addition of NR had a greater inhibitory effect on the β-crystalline phase in the blends. When its amount reached 30 phr (by mass), the X-ray diffraction peaks disappeared in the blends, with the smallest amount of particles on the fracture surface, and the highest crosslinking density.

In order to improve the adhesion between high-viscosity modified asphalt and aggregates, high-viscosity modified asphalt (HVAM-2) based on C9 petroleum resin, styrene-butadiene-styrene block copolymer and waste rubber powder was prepared, and the contact angle between it and aggregates was determined and the adhesion work was calculated by titration method. The adhesion of the HVAM-2 mixture was further verified by freeze-thaw splitting test, soak-and-fly test and Hamburg rutting test. The results showed that the lattice structure formed by C9 petroleum resin, styrene-butadiene-styrene block copolymer and waste rubber powder in asphalt could greatly improve the adhesion of asphalt and the bonding ability between asphalt and aggregates. Compared with the base asphalt, the adhesion work of HVAM-2 was increased by 72.9%, and HVAM-2 asphalt mixtures had good water stability.

The flame retardancy and smoke suppression performance of silicone rubber foam (SiFs) greatly affected its promotion and application in the field of high performance materials. Improving the flame retardancy and smoke suppression performance of SiFs had became a hot and difficult topic in recent years. The current research status of flame retardancy and smoke suppression of SiFs in flame retardant systems such as metal hydroxide flame retardants, boron- based flame retardants, phosphorus-and nitrogen-based flame retardants, platinum catalysts, microcapsule flame retardants, and ceramic-based flame retardants had been summarized with 67 references. Besides, the corresponding flame retardancy mechanisms had been expounded. Finally, the future research direction of flame retardancy and smoke suppression of SiFs was presented.

The research progress in thermal aging resistant silicone rubber based heat-proof materials in recent years was reviewed with 46 references. The inorganic modification effects of nano-carbon materials, graphite powder, talc powder, transition metal oxides and fiber fillers on the thermal aging resistance and mechanical properties of silicone rubber based heat-proof materials were emphatically introduced, and the main research directions of thermal aging resistant silicone rubber based heat-proof materials in the future were pointed out.

The current application status of insulators and characteristics of composite insulators were introduced, the high temperature vulcanized silicone rubber and its reinforcing fillers, flame retardants, colorants and other additives used in composite insulator umbrella skirt materials were summarized, as well as the research progress of umbrella skirt processing technology and defect detection technology. Suggestions were put forward for research of umbrella skirt materials.

The combination method of numerical simulation and experimental verification was used to optimize the current evaluation method of tear strength of rubber unnicked angle test piece. Firstly, the tear energy at angle position of rubber test piece with different clamp distances was simulated by the simulation software, and then advanced video extensometer-digital image correlation analysis software was used to obtain the strain distribution cloud nephograms and the multi-location strain curves of the test piece with time. A new method was proposed to evaluate comprehensively the unnicked angle tear property by combining strain distribution cloud nephogram and corrected tear strength, and the method applicability was verified by the tear strength test of pure natural rubber and natural rubber/synthetic rubber blends. The results showed that the tensile degree of the non-effective test region and the tear energy at angle position were all different with the different clamp distances, when the other para-meters of the test piece were the same, which increased the volatility of the test results. Compared with the standard currently in effect, the variation coefficient of parallel test results could be reduced by using the corrected tear strength, and the test results was positively correlated with the carbon black dispersion in the vulcanizates.

"High trans-1,4-selective coordination chain transfer polymerization of butadiene was achieved through the catalysis of isopropoxyl neodymium/n-butyl magnesium catalyst system, the non-polar-polar diblock copolymer of trans-1,4-polybutadiene and polymethyl methacrylate （TPB-b-PMMA) was prepared after the addition of polar monomer methyl methacrylate（MMA）, and molecular weight and its distribution, microstructure, and surface morphology and micromorphology of the block copolymer thin film were characterized by gel permeation chromatography（GPC）, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, atomic force microscope, and transmission electron microscope. The results indicated that GPC curve of the obtained block copolymer showed single peak and the molecular weight distribution were relatively narrow （polydispersity index less than 2.5); the mole fraction of trans-1,4- unit of trans-1,4-polybutadiene segment in block copolymers was 95.8% and the mole fraction of MMA unit could be controlled within the range of 10.9% to 39.7%; the semicrystalline block copolymer thin film had a phase separation morphology with a cylindrical micro domain size of 25 nm. "

High- content rubber asphalt （HCRA) was prepared by using highly devulcanized rubber （DR), the effects of maleic anhydride （MAH) pre-grafted devulcanized rubber （DR) modification and direct blending modification of MAH and DR on the structure and properties of HCRA were comparatively studied by attenuated total reflection Fourier transform infrared spectrometer, gel permeation chromatography, dynamic shear rheometer and dynamic mechanical analyzer, and the modification mechanisms of two modification methods were explored. The results showed that during the pre-grafting of MAH onto DR, the free radical substitution reaction with active sites provided by olefin double bonds and allyl hydrocarbon atoms occurred, while when MAH and DR were directly blended with asphalt, there were two reactions: free radical substitution reaction and esterification, the latter being the main one. The sol components of MAH-modified HCRA were mainly composed of low and medium molecular weight components. The MAH improved significantly the high- and low-temperature rheological properties of HCRA. In addition, both the modification methods had an impact on the structure and properties of HCRA, and there were significant differences with the change of addition amount of MAH.

"With BE type rubber isolator as the research object, the hyperelastic and viscoelastic constitutive parameters of rubber materials were inverted through ABAQUS and ISIGHT joint simulation, based on the rated parameters of the isolator, and the prediction model of the rubber isolator was established using the inversion parameters. The results showed that the errors of the vertical, direction, and transverse static stiffness and three-dimensional dynamic stiffness were all less than 7%. When the prediction model was used to explore the effects of frequency, amplitude, and preload of rubber isolator on dynamic stiffness, the simulation results were basically consistent with the experimental results of similar rubber devices. When the prediction model was applied in the system level vibration simulation, the simulation results could match the vibration test results well. "

"First, a layer of inorganic self-assembled microencapsulated ammonium polyphosphate （APP) （SiO2@APP) was formed on the surface of APP using alkaline silica sol, and then grafting modified APP （KH 580-SiO2@APP) flame retardant was prepared via grafting modification of the silane coupling agent 3-mercaptopropyltriethoxysilane （KH 580) onto the surface of SiO2@APP by sol-gel method. Meanwhile, natural rubber （NR) composites were prepared by the application of KH 580-SiO2@APP to NR, and the effects of APP surface modification on the hydrophobicity, thermal stability, flame retardancy, and physical and mechanical properties of NR composite materials were studied. The results indicated that the surface modification of APP was successful. Compared with APP, the water contact angle of the resulting SiO2@APP increased by 205.7% and the thermal stability increased by about 25.7% after the modification with alkaline silica sol, and in the meantime, compared with APP/NR composite material, the tensile strength of SiO2@APP/NR composite increased by 43.7%, but the limited oxygen index （LOI) decreased. After the modification of SiO2@APP with the silane coupling agent KH 580, the water contact angle of the resul-ting KH 580-SiO2@APP increased by 9.1% and the increase in thermal stability was nearly 11.6%. In additon, the tensile strength of KH 580-SiO2@APP/NR composite was improved to 16.2 MPa, and the elongation at break increased by 539%, while the LOI decreased slightly to 24.3%. "

The reclamation law of natural rubber reinforced with silica （SNR) swollen by a small amount of soybean oil at different temperatures and in different time was studied, and the chemical composition and micromorphology of the reclaimed pro-ducts were determined. The results showed that within the temperature range of 160 and 240 ℃, the sol content of SNR increased continuously with the increasing temperature after swollen by soybean oil of 20 phr （mass), and when reclaimed at 220 ℃ for 15 min, the mass fraction of sol in the reclaimed product increased to 50.5%, and the mass fraction of sol in the reclaimed product was only 28.7% at 200 ℃, which indicated that 220 ℃ was an important turning point temperature in the reclamation process of SNR. The increase in oxygen content in the reclaimed product was due to the violent oxidation reaction of SNR during the reclamation process. In addition, as the degree of reclamation increased, the thickness of bound rubber of loose strata on the surface of silica decreased from 25 nm to 8 nm, indicating that thermal-oxidative reclamation could achieve a high degree of detachment between nano silica and its surface bound rubber.

The effects of common vulcanization （CV) system, semi-effective vulcanization （SEV) system, effective vulcanization （EV) system, and dicumene peroxide （DCP) vulcanization system on the mechanical properties and electromagnetic shielding effectiveness of Eucommia ulmoides gum （EUG) composites were studied. The results showed that the difference in vulcanization rates of CV system, SEV system and EV system was not significant, and the DCP vulcanization system had the lowest vulcanization rate and crosslinking degree, and exhibited the highest crystallinity degree. The elongation at break of EUG composites of the sulfur vulcanization systems were all higher than that of EUG composite of the peroxide vulcanization system, but the tensile strength was lower, and when DCP was used as the vulcanization agent, the tensile strength of EUG composite could increase by up to 10.6% compared with that of EUG composites of the sulfur vulcanization systems. EUG composites of sulfur vulcanization system exhibited good conductivity and the higher crosslinking density, which was conducive to the formation of conductive network, and the electromagnetic shielding effectiveness of EUG compo-sites of the EV system was 22% higher than that of EUG composites of the unvulcanized system.

A bio-based shape memory composite was prepared with chitosan as filler and deproteinized epoxidized natural rubber （ENR) as matrix, and the microstructure, mechanical properties, and shape memory performance of the shape memory composite materials were investigated by Fourier transform infrared spectroscopy, atomic force microscope, electronic universal testing machine, etc. The results showed that the addition of chitosan dispersed the ordered crystalline phases of ENR into smaller and more uniformly sized particles throughout the system. Due to the strengthening and toughening effect of chitosan, the abrasion resistance of the shape memory composite material was enhanced and its mechanical properties improved gradually. Furthermore, the addition of chitosan further improved the shape memory performance of ENR.

The effects of conventional vulcanization （CV) system, semi-effective vulcanization （SEV) system, effective vulcanization （EV) system, peroxide 1,3-bis（tert-butylperoxyisopropyl) benzene （BIBP)/triallyl isocyanurate （TAIC) vulcanization system, and phenolic resin SP 1045 vulcanization system on properties of poly（di-n-butyl itaconate-co-butadiene) rubber were studied. The results showed that the vulcanization rate of BIBP/TAIC vulcanization system was the fastest, while the vulcanization rate of SP 1045 vulcanization system was the slowest, and the vulcanization rate of CV system, SEV system, and EV system increased gradually in sequence. The crosslinking densities of the vulcanizates of the sulfur vulcanization systems in descending order were CV system, SEV system and EV system. Tensile strength of all the vulcanizates in descending order were SEV system, SP 1045 vulcanization system, CV system, EV system and BIBP/TAIC vulcanization system, in which elongation at break and tear strength of the vulcanizate of EV system were the largest, and the wear resistance of the vulcanizate of CV system was the best. The vulcanizate of BIBP/TAIC vulcanization system had the best thermal-oxydative aging property. Compared with the sulfur vulcanization systems, the glass transition temperatures of the vulcanizates of BIBP/TAIC and SP 1045 vulcanization systems shifted significantly towards to the high-temperature direction. The loss factor at 60 ℃ and rolling resistance of the vulcanizate of CV system were both the smallest. The effective damping temperature range of the vulcanizate of EV system was the widest.

Trial production and performance evaluation of finished tires were conducted with domestically produced double-end functional solutionpolymerized styrene-butadiene rubber SSBR 2060-N and single-end functional product ■from Zeon Corporation of Japan. The results showed that the finished tires produced from SSBR 2060-N conformed to the technical standards in terms of external dimensions, and the wet-skid resistance and rolling resistance met the double B-class tire specified by the tire labeling regulations EU 2020/740, jointly enacted by the European Parliament and the Council of the European Union. The strength performance, high-speed performance, and durability of the tires were comparable to those of the finished tire prepared with ■ and met the requirements of national standards.

Chlorinated polyethylene （CPE) flame retardant composites were prepared with CPE as the matrix material and sepiolite as flame retardant, and the effects of the addition amount of sepiolite on cu-ring characteristics, physical and mechanical properties, and flame retardance were studied. The results showed that with the increase in the addition amount of sepiolite, tensile strength, tear strength, modulus at 100%, modulus at 300%, and Shore A hardness of the composites increased significantly; the addition of sepiolite improved limiting oxygen index of the CPE flame retardant composites, reduced the maximum heat release rate and total heat release during combustion of the composites, prolonged the ignition time of the composites, reduced the absolute content of carbon monoxide and carbon dioxode, and decreased the smoke emission.

Silica was co-modified by silane coupling agent γ-aminopropyl triethoxysilane （APTES) and lauric acid （LA), the co-modified silica/solution-polymerized styrene-butadiene rubber （SSBR) composite was prepared, and the effects of co-modified silica by APTES and LA on curing characteristics, mechanical properties, wet skid resistance, and rolling resistance of SSBR composites were studied. The results showed that the mass loss of silica between 30 ℃ and 200 ℃ decreased by 54%, and the agglomeration was significantly improved after the co-modification. The optimum curing time of co-modified silica/SSBR composite was 20.45 min, tensile strength reached 18.8 MPa, and loss factors at 0 ℃ and 60 ℃ were 0.678 8 and 0.100 3, respectively.

Ethylene-butadiene-（5-ethylidene-2-norbornene) terpolymer （EBT)/nitrile rubber （NBR) blends were prepared by blending method, and the effects of different blending ratios on curing characteristics, physical and mechanical properties, compression set, aging resistance, low temperature resistance, glass transition temperature and oil resistance of EBT/NBR blends were studied. The results indicated that with the increase of EBT content, tensile strength, tear strength and elongation at break of the blends decreased gradually, while hardness and modulus increased gradually, and compression set got larger gradually. With the increase of EBT content, the hot-air aging resistance of the blends showed a trend of first decreasing and then increa-sing with improved ozone aging resistance and better low temperature resistance, but the oil resistance decreased. When m（EBT)/m（NBR) was 30/70, the comprehensive mechanical properties and oil resistance of the blend decreased slightly, but the low temperature resistance and ozone aging resistance improved significantly.

The causes and adverse effects of thermal problems in the polymer rubber extrusion process were analyzed, the current research status of thermal management in rubber extrusion at home and abroad in recent years were summarized from the aspects of screw structure optimization, external coo-ling improvement, internal heat transfer enhancement and application of field synergy principle on heat transfer enhancement with 48 references, and prospects were made for the development direction of thermal management in rubber extrusion.

The transfer mechanism and process characteristics of polymer devolatilization were briefly described， and the mechanism and process intensification of devolatilization mass transfer were introduced. The methods of polymer devolatilization process intensification were summarized from the devolatilization equipment and devolatilization process， and it was pointed out that the new devolatilization equipment and process were the key to realize the high-efficiency devolatilization of polymer. The research status and development trend of new technologies of polymer devolatilization， such as supercritical fluid， ultrasonic cavitation and high gravity were emphatically expounded with 62 refe-rences.

The change characteristics of production capacity, output, import and export quantity, apparent consumption of main synthetic rubber pro-ducts of China in 2023 were retrospected, the status of supply and demand of butadiene as well as price changes of main rubber varieties were introduced, and the developing trend of China′ synthetic rubber industry in 2024 was prospected.

Based on cations of diazo group, imino group and nitrogen-rich azole, the synthetic strategies and properties of az-ole, bis-azoles and fused heterocycle-based zwitterionic energetic materials were reviewed in recent ten years, and the influence of molecular structures on their energetic performance and stability was clarified. Meanwhile, the future directions on the zwitterionic energetic materials based on nitrogen-rich azoles were pointed out: (1) Diazonium zwitterionic energetic materials outperform DDNP in detonation performance, warranting deeper research into heat-resistant explosives, harnessing alkyl-bridged, fused-ring nitrogen-rich azoles. (2) The imino-gem-dinitromethyl zwitterionic energetic materials can alleviate the sensitivity of diazonium salts, but their thermal stability still requires further optimization. (3) The modifiable structure of nitrogen-rich azole cation energetic salts and explosive groups, and synergies with ionic salts, cocrystals should be fully explored, which could effectively expand their applications in high-energy insensitive explosives, high-energy propellants, green gas generators, and heat-resistant energetic materials. [ABSTRACT FROM AUTHOR]

By using amino sulfonic acid salts, formaldehyde, and glyoxal as starting materials, an optimized synthesis process for 2,4,6, 8-tetrachitro-2,4,6, 8-tetraazabicyclic [3.3.0] octane(BCHMX) without purification of the intermediate (2,4, 6,8-tetraazabicyclo[3. 3.0]octane sulfonate) was developed. The molecular structure, crystal structure, and thermal stability of the target product were analyzed and characterized using Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H NMR), carbon-13 nuclear magnetic resonance spectroscopy (13C NMR), and thermo-gravimetric analysis combined with differential scanning calorimetry (TC-DSC). Results show that, the optimal process conditions are as follows: 1. 07 mole of potassium amino sulfonate per mole of formaldehyde, 1. 77 mole of glyoxal, 8.4 mole of water as the solvent, and 0. 023 mole of formic acid as the acid catalyst. The condensation reaction is carried out for 12 hours. The nitration reaction is performed using fuming nitric acid and acetic anhydride in a molar ratio of 1. 3 ' 1 as nitrating agent at 40°C . By the condensation and nitration reactions, BCHMX with a purity of 97.8% is obtained with a total yield of 65. 29% . BCHMX belongs to the monoclinic crystal system with space group of P2(1)/c, and the theraml decomposition temperature is 223 °C . [ABSTRACT FROM AUTHOR]

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Nitrile rubber （NBR） 2980 M was prepared by mechanical blending of liquid nitrile rubber （YN 25） into NBR 2980. The effect of YN 25 addition ratio on the Mooney viscosity, hardness, vulcanization characteristics of NBR 2980 M compound, and tensile properties of NBR 2980 M vulcanizate were studied. The results showed that with the increase of YN 25, Mooney viscosity, modulus at 300% at 50 min, tensile strength, maximum and minimum torque of NBR 2980 M all decreased li-nearly, while the elongation at break and three torque differences vulcanization times of 25 min, 50 min, and 90 min all increased linearly. However, the change in hardness of the compound was not significant. For increase in mass fraction of YN 25 in NBR 2980 M by 1%, Mooney viscosity of the compound decreases by 0.78, and the modulus at 300%, tensile strength, maximum and minimum torque of the vulcanizate decrease by 0.25 MPa, 0.17 MPa, 0.12 dN·m, and 0.02 dN·m, respectively. The elongation at break and three vulcanization times of 25 min, 50 min, and 90 min increase by 4.1%, 0.05 min, 0.08 min, and 0.18 min, respectively.

Flame retardant ceramic silicone rubber was prepared by dehydrogenation condensation using α,ω-hydroxy-terminated polysiloxane as matrix, and composite ceramic powder and fumed silica as fillers. The effects of the amount of composite ceramic powder, type of raw rubber side groups and ablation temperatures on the properties of the flame retardant ceramic silicone rubber were investigated. The results showed that the physical and mechanical properties of 107 silicone rubber containing side methyl group were almost the best when the amount of composite ceramic powder was 120 phr (mass), the tensile strength was 4.69 MPa, elongation at break was 686%, Shore A hardness was 48 and flexural strength was 12.29 MPa. Compared with 107 silicone rubber and 108 silicone rubber containing pendant phenyl group, the ceramic silicone rubber prepared from 109 silicone rubber containing pendant methyl vinyl group had better thermal stability, and the residual carbon mass fraction of composite up to 86% at 1 000 ℃. The ceramic silicone rubber from 109 silicone rubber had better flame retardancy, the limiting oxygen index was 49.5%, and the vertical combustion grade was V-0. In addition, it had a lower ceramization temperature and a good ceramization effect at 600 ℃.