Study on the Mechanism and Experiment of Styrene Butadiene Rubber Reinforcement by Spent Fluid Catalytic Cracking Catalyst.

Spent Fluid Catalytic Cracking (FCC) Catalyst is a major waste in the field of the petroleum processing field, with a large output and serious pollution. The treatment cost of these waste catalysts is high, and how to achieve their efficient reuse has become a key topic of research at home and abroad. To this end, this paper conducted a mechanistic and experimental study on the replacement of some carbon blacks by spent FCC catalysts for the preparation of rubber products and explored the synergistic reinforcing effect of spent catalysts and carbon blacks, in order to extend the reuse methods of spent catalysts and reduce the pollution caused by them to the environment. The experimental results demonstrated that the filler dispersion and distribution in the compound are more uniform after replacing the carbon black with modified spent FCC catalysts. The crosslinking density of rubber increases, the Payne effect is decreased, and the dynamic mechanical properties and aging resistance are improved. When the number of replacement parts reached 15, the comprehensive performance of the rubber composites remained the same as that of the control group. In this paper, the spent FCC catalysts modified by the physical method instead of the carbon-black-filled SBR can not only improve the performance of rubber products, but also can provide basic technical and theoretical support to realize the recycling of spent FCC catalysts and reduce the environmental pressure. The feasibility of preparing rubber composites by spent catalysts is also verified.

Study on synergistic pyrolysis and kinetics of mixed plastics based on spent fluid-catalytic-cracking catalyst.

At present, disposable plastic products such as plastic packaging are very common in our daily life. These products are extremely easy to cause serious damage to the soil and marine environment due to their short design and service life, difficulties in degradation, or long degradation cycles. Thermochemical method (pyrolysis or catalytic pyrolysis) is an efficient and environmentally friendly way to treat plastic waste. In order to further reduce the energy consumption of plastic pyrolysis and improve the recycling rate of spent fluid catalytic cracking (FCC) catalysts, we adopt the "waste-to-waste" approach to apply the spent FCC catalysts as catalysts in the catalytic pyrolysis of plastics, exploring the pyrolysis characteristics, kinetic parameters, and synergistic effects between different typical plastics (polypropylene, low-density polyethylene, polystyrene). The experimental results show that the spent FCC catalysts used in the catalytic pyrolysis of plastics are beneficial to reduce the overall pyrolysis temperature and activation energy, in which the maximum weight loss temperature decreases by about 12 â„ƒ and the activation energy decreases by about 13%. The activity of spent FCC catalysts is improved after modification by microwave and ultrasonic, which further improve the catalytic efficiency and reduce the energy consumption of pyrolysis. The co-pyrolysis of mixed plastics is dominated by positive synergistic effect, which is conducive to improving the thermal degradation rate and shortening the pyrolysis time. This study provides relevant theoretical support for the resource application of spent FCC catalysts and "waste-to-waste" treatment of plastic waste.

The Effect of Different Dosages of TESPT on Metal Friction and Metal Wear in the Mixing Process.

Studies show that the dispersion of silica in the mixing process is an important factor affecting the wear of the mixing chamber. As the most important mixing equipment, the long operational life of the internal mixer will cause wear in the rotor and chamber of the internal mixer. This wear increases the gap between the rotor and chamber of the internal mixer, reduces the mixing performance, weakens the dispersion of packing, and adversely affects the quality of the rubber produced. Therefore, it is important to investigate the metal wear in the mixing process. This article examines the effect of the addition of different amounts of silane coupling agents on metal friction and wear during the mixing process. The silane coupling agent has two functions. The first is to make the surface of the silica hydrophobic, enabling it to combine the inorganic matrix of the silica with the organic matrix of the rubber; the second is to inhibit the aggregation of the silica in the rubber. In the present study, we examine (1) the influence of different formulations on the friction and wear of the metal in the mixing chamber from the perspective of formulation technology, and (2) the correlation between corrosion wear and abrasive wear. It is found that a rubber compound with 6 phr of TESPT has the lowest metal wear and that adding more TESPT does not affect the degree of metal wear. As the amount of TESPT increases, the proportion of abrasive wear decreases, while the proportion of corrosive wear increases, reaching a maximum of 20.7%. In our study we found that abrasive wear is the predominant wear mechanism of a rubber compound on metal. In contrast, the corrosive wear caused by high-temperature water vapor still occupies a large proportion of the total wear. Therefore, improving silica dispersion and reducing abrasive wear are extremely important methods to protect the mixing chamber. However, the corrosion of metals by high-temperature water vapor should also be considered when preparing for the mixing process.

Experimental Study on the Characterization of Orientation of Polyester Short Fibers in Rubber Composites by an X-ray Three-Dimensional Microscope.

Polyester-short-fiber-reinforced rubber composites have been detected by an X-ray three-dimensional microscope, and then the three-dimensional reconstruction of the image has been carried out to characterize the orientation of polyester short fibers in the composites for the first time. Based on the summary of three traditional methods and mechanisms of characterizing the orientation of polyester short fibers by the numerical parameter method, the direct test method, and the indirect test method, the method and mechanism of the X-ray three-dimensional microscope applied to the orientation characterization of polyester short fibers have been studied. The combination of the center point and threshold segmentation methods has been used to distinguish which fiber section belongs to the same fiber, and the identification of the whole short fiber in different slice images has been realized for the first time. Moreover, Avizo software has been used to realize the three-dimensional reconstruction of a polyester short fiber scanning image. The obtained data have been integrated and the orientation angle and orientation degree have been quantitatively characterized for the first time. This has filled the key technical problem of quantitative characterization of the orientation angle and orientation degree of polyester fibers. The image has been verified by 3Dmed software, and furthermore, the accuracy of the three-dimensional reconstruction results has been verified.

Effect of Wet Mixing on Properties of Radial-Orientation Basalt Fiber-Reinforced Rubber Compounds.

The effects of wet mixing and traditional mixing on the properties of radial-orientation basalt fiber-reinforced rubber products were studied through experiments. The results show that compared with traditional mixing, the basalt fibers under the wet mixing conditions can more effectively enhance the physical and mechanical properties of composites. The properties of the composites, such as carbon black dispersion, filler dispersion, rolling resistance and wet-sliding resistance, were the best after the latex and carbon black were premixed and then mixed by a mixer. Through extrusion experiments with the developed short-fiber radial-orientation die, it can be found that the fluidity of composites after extrusion is enhanced. Through analysis utilizing an electron microscope, it is shown that when the BFs added with KH550 (3-Aminopropyltriethoxysilane) were modified by KH560 ((3-Glycidyloxypropyl)trimethoxysilane), the interface layers of BF (basalt fiber)-KH560-NR and BF-KH550-NR were formed, which improves the adhesion between BFs and the rubber matrix. Qualitative characterization experiments on the orientation direction of the vulcanized composites were carried out through the experiments; that is, the qualitative characterization experiments on the segmented cutting and vulcanization of the composites in the radial direction showed that the short-fiber radial-orientation die could greatly improve the radial orientation degree of the short fibers in the radial direction. After adding KH560, the performance of the composites reinforced by the short fibers was improved to a certain extent compared with those without KH560. By adding DZ (N,N-Dicyclohexyl-2-benzothiazolsulfene amide) and CTP(cytidine triphosphate disodium) into the vulcanization system, the curing process of compounds in mixing and extrusion was delayed and the scorching resistance of short-fiber-reinforced composites was enhanced. Under the same conditions, the properties of the compounds after extrusion were greatly improved compared with those without extrusion.

Numerical Optimization Simulation of Synchronous Four-Wing Rotor.

The mixer is the most widely used batch mixing equipment in the rubber industry. The rotor is a core component and has a great impact on the mixing effect of the equipment. The current rotor structure design is done empirically, being tightly dependent on practical experience. This paper proposes a method for optimizing the rotor structure by using optimization algorithms combined with numerical simulation technology. Using MATLAB software, a parametric design program for synchronous rotors and a set of optimization programs for the particle swarm optimization (PSO) algorithm were written. The global distribution index was used as the fitness function to optimize the synchronous rotor configuration. A comparative analysis of the rotors before and after optimization shows that the optimization process is feasible, and the results are reliable. This provides new ideas for the design and development of mixer rotors.

Study on the Pyrolysis Kinetics and Mechanisms of the Tread Compounds of Silica-Filled Discarded Car Tires.

The disposal of used automobile tires is a major waste concern. Simply stacking tires and allowing them to decompose will harbor breeding mosquitoes that spread viruses, whereas burning them will release acidic and toxic gases. Therefore, one viable option is pyrolysis, where elevated temperatures are used to facilitate the decomposition of a material. However, the lack of theoretical support for pyrolysis technology limits the development of the pyrolysis industry when it comes to discarded tires. The purpose of this research is to put forward a brand-new multi-kinetic research method for studying materials with complex components through the discussion of various kinetic research methods. The characteristic of this kinetic research method is that it is a relatively complete theoretical system and can accurately calculate the three kinetic factors considered during the pyrolysis of multicomponent materials. The results show that the multi-kinetic research method can obtain the kinetic equation and reaction mechanism for the pyrolysis of tires with high accuracy. The pyrolysis process of this compound was divided into two stages, Reaction I and II, where the kinetic equation of Reaction I was f ( α ) = 0.2473 α - 3.0473 , with an activation energy of 155.26 kJ/mol and a pre-exponential factor of 5.88 × 109/min. Meanwhile, the kinetic equation of Reaction II was f ( α ) = 0.4142 ( 1 - α ) [ - ln ( 1 - α ) ] - 1.4143 , while its activation energy was 315.40 kJ/mol and its pre-exponential factor was 7.86 × 1017/min. Furthermore, based on the results of the research analysis, the reaction principles corresponding to Reaction I and Reaction II in the pyrolysis process of this compound were established.

Effect of Gear Pump Extrusion Processing on the Properties of Fiber Reinforced Rubber Composites.

Short fiber reinforced rubber composites have been widely used in rubber products attributed to their excellent wear resistance. However, there are still some serious problems in the processing of short fiber reinforced rubber composites, such as Mooney viscosity increasing, temperature and extrusion pressure rising, and unstable extrusion quality. In particular, short fibers need to be extruded in a specific direction during the molding process, and the problems in this process are particularly prominent. In this manuscript, the influence of gear pump assisted extrusion on the properties of short fiber rubber composites is studied. The experimental results show that the application of a gear pump to assist extrusion could significantly increase the die pressure, reduce the extrusion temperature of the blend, and improve the extrusion efficiency and stability of the blend. Furthermore, it could improve the vulcanization efficiency, increase the tensile strength and tear strength of the compound, reduce wear, and guarantee the quality of extrusion products.

Optimization of Serial Modular Continuous Mixing Process Parameters for Natural Rubber Composites Reinforced by Silica/Carbon Black.

In the tire industry, the combination of carbon black and silica is commonly utilized to improve the comprehensive performance of natural rubber so as to realize the best performance and cost-effectiveness. The corresponding mixing is divided into three processes (initial mixing, delivery, reactive mixing) by the serial modular continuous mixing method, thus achieving more accurate control of the mixing process, higher production efficiency and better performance. Moreover, the optimization of serial modular continuous mixing process parameters can not only improve the performance of composite materials, but help people understand the physical and chemical changes and the reinforcing mechanism of fillers in the mixing process. In this paper, the relationship among the parameters of eight processes and filler network structure, tensile strength, chemical reinforcing effect and tear resistance was explored through experiments. The deep causes of performance changes caused by parameters were analyzed. Consequently, the best process condition and the ranking of the influencing factors for a certain performance was obtained. Furthermore, the best preparation process of natural rubber (NR)/carbon black/silica composite was achieved through comprehensive analysis.