HC Plastics News:
Plastic products are found everywhere in our daily lives and are extremely versatile. However, as a raw material for the production of plastics, phenol, etc., its industrial production process is often high energy consumption and high pollution, and there are problems such as excessive oxidation and low yield, and many undesirable by-products. Recently, experts from Nanjing University of Technology have achieved important results in the reaction of phenolic compounds catalyzed by zeolitic molecular sieves to prepare phenolic compounds, which contributes to the efficient production of plastic products. The related papers are published in Nature Communication.
Phenolic compounds, such as phenol and cresol, are a wide range of widely used chemicals that can be used in the preparation of pesticides, pesticides, plastics, dyes, pharmaceuticals, polymers, and the like. The urgent pressure of energy and environment requires the development of green chemical processes. In the industrial production process, it is urgent to use new catalytic processes with high selectivity and high atomic utilization. This development relies mainly on the development and development of new catalytic materials.
In order to break the bottleneck of high energy consumption and high pollution in the production process, Professor Wang Jun and Associate Professor Zhou Yu of the State Key Laboratory of Materials Chemical Engineering and the School of Chemical Engineering of Nanjing University of Technology, together with Professor Yan Ning of the National University of Singapore, used clean oxygen sources such as hydrogen peroxide to pass the environment. The friendly benzene hydroxylation reaction produces phenolic compounds in a single step in a highly efficient and environmentally friendly manner, unlike conventional methods requiring cumbersome multiple reaction steps, high energy consumption, high pollution, and low yield.
"Benzene is an inert substrate, and its product phenol is more active than benzene. In the preparation of phenol in the past, in the process of producing phenol, the phenol will continue to oxidize, resulting in a series of serious side reactions." Professor Zhou Yu said that the use The utilization rate of conventional catalysts is not high, and the reaction time is often as long as ten to several tens of hours, which is difficult to meet the needs of industrial catalysis. “Our research group has used innovative methods to prepare zeolite molecular sieve catalysts containing vanadium, silicon and oxygen. By using this new catalyst, when hydrogen peroxide reacts with benzene to produce phenol, it will not cause adverse reactions with relatively active phenol. Reaction, producing bad by-products."
The new catalyst developed by the research group allows the hydrogen peroxide to be "directed" to react only with benzene, and the phenol is directly prepared in one step, and the yield of pure phenol is extremely high. In the course of the reaction, only water is produced, and no other wastes and other pollution emissions are green. Moreover, this new type of catalyst can instantaneously react and greatly improve the efficiency of obtaining phenol.
The use of this catalyst is expected to achieve industrial green production of phenolic compounds such as phenol, thereby replacing the original high energy consumption and high pollution path, achieving energy saving, sustainable development of chemical processes, and therefore has important industrial application prospects.
Interestingly, the innovative preparation method of this catalyst has a wide range of universality, and can further construct zeolite molecular sieves containing different metals, such as iron, copper, manganese and the like, to prepare a highly efficient heterogeneous catalyst. Other types of chemicals can benefit from green production. 
Editor in charge: Yao Chunlin
Alnico (AlNiCo) is the first developed a permanent magnet is made of aluminum, nickel, cobalt, iron and other trace metals composition of an alloy.According to different production process is divided into sintered Alnico (Sintered AlNiCo), and cast aluminum nickel and cobalt (Cast AlNiCo).Product shape of the round and square. Sintered products limited to the small size, their production out of rough tolerance is better than the rough cast product can be better workability.
Alnico alloys can be magnetised to produce strong magnetic fields and have a high coercivity (resistance to demagnetization), thus making strong permanent magnets. Of the more commonly available magnets, only rare-earth magnets such as neodymium and samarium-cobalt are stronger. Alnico Magnets produce magnetic field strength at their poles as high as 1500 gausses (0.15 teslas), or about 3000 times the strength of Earth's magnetic field. Some brands of alnico are isotropic and can be efficiently magnetized in any direction. Other types, such as Alnico 5 and alnico 8, are anisotropic, with each having a preferred direction of magnetization, or orientation. Anisotropic alloys generally have greater magnetic capacity in a preferred orientation than isotropic types. Alnico's remanence (Br) may exceed 12,000 G (1.2 T), its coercivity (Hc) can be up to 1000 oersteds (80 kA/m), its energy product ((BH)max) can be up to 5.5 MG·Oe (44 T·A/m). This means that alnico can produce a strong magnetic flux in closed magnetic circuits, but has relatively small resistance against demagnetization. The field strength at the poles of any permanent magnet depends very much on the shape and is usually well below the remanence strength of the material.
Alnico alloys have some of the highest Curie temperatures of any magnetic material, around 800 °C (1,470 °F), although the maximal working temperature is normally limited to around 538 °C (1,000 °F).[4] They are the only magnets that have useful magnetism even when heated red-hot.[5] This property, as well as its brittleness and high melting point, is the result of the strong tendency toward order due to intermetallic bonding between aluminium and other constituents. They are also one of the most stable magnets if they are handled properly. Alnico magnets are electrically conductive, unlike ceramic magnets.
Alnico magnets are widely used in industrial and consumer applications where strong permanent magnets are needed; examples are electric motors, electric guitar pickups, microphones, sensors, loudspeakers, magnetron tubes, and cow magnets. In many applications they are being superseded by rare-earth magnets, whose stronger fields (Br) and larger energy products (BHmax) allow smaller-size magnets to be used for a given application.
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