Application background and overview of 2,6-di-tert-butylpyridine
2,6-Di-tert-butylpyridine is a special electron donor. Due to the steric hindrance effect, it can quantitatively react with small protons. It is also called a proton capture agent. In the study of 5-tert-butylpyridine, When using the -1,3-dicumyl chloride/TiCl4/2,6-di-tert-butylpyridine system, it is believed that 2,6-di-tert-butylpyridine can only capture protons. Some studies have pointed out that while 2,6-di-tert-butylpyridine captures protons, it also interacts or reacts with Lewis acid polycarbonate and carbocation electrophiles to a certain extent, thereby achieving living polymerization.
Applications of 2,6-di-tert-butylpyridine
2,6-di-tert-butylpyridine was used to prepare polymeric barium carbonate with n-type nitrogen oxide pendant groups. In the study of reactive/controlled cationic polymerization of isobutylene, an initiating system composed of initiator/co-initiator/electron donor is usually used: The initiator is an organic tertiary ester, tertiary ether, tertiary chlorine and other compounds, such as cumyl acetate. , cumyl methyl ether, p-dicumyl chloride, 3-chloro-2,6,6-trimethylpentane, etc.; the co-initiator is titanium tetrachloride, boron trifluoride, aluminum trichloride, dichloride, etc. Lewis acids such as ethyl aluminum chloride; electron donors are dimethylacetamide, dimethyl sulfoxide, triethylamine,
Pyridine, etc., by adding these electron donors, good living polymerization characteristics can be obtained. However, there has always been controversy about the mechanism of the role of electron donors in cationic polymerization. Currently, there are three representative views: 1) Carbocation stabilization, that is, electron donor reagents or their complexes with Lewis acid Combined with the end of the growing chain to reduce the “cationicity” of the active center cation, inhibit side reactions, and make the polymerization reaction exhibit the characteristics of living polymerization; 2) proton capture, inhibiting the uncontrollable initiation of protons and chain transfer reactions; 3 ) Inhibits the growth of free ions, that is, the electron donor reacts with the proton source and Lewis acid to generate homonegative ions, resulting in the homoion effect, which inhibits the growth of the free ion active center. Studies have been conducted at -80 ℃ with methyl chloride. Using hexane as solvent, 2,6-di-tert-butylpyridine (DtBP) reacts with 2-chloro-2,4,4-trimethylpentane (TMPCl)/titanium tetrachloride (TiCl4) system to induce isobutylene (IB) The influence of the relative molecular weight, molecular weight distribution, and conversion rate of the cationic polymerization reaction was investigated, and the functional relationship between the conversion rate and the reaction time was investigated when the concentration of DtBP in the system changed, and a kinetic study was conducted. The results show that DtBP plays the following roles in the process of initiating IB cationic polymerization using TMPCl/TiCl4/DtBP as the initiating system: 1) Proton capture, intercepting protons generated by impurities and water during the initiating stage and the β-end of the growing chain H removes the protons produced; 2) The stabilizing effect of carbocation reduces the apparent rate of polymerization reaction, improves the initiating efficiency of the initiator, and converts the inactive polymerization process into an active polymerization process.
In addition, 2,6-di-tert-butylpyridine can also be used in organic radical batteries. Microbial fuel cells (MFC), as a new method of using microbial metabolism to generate electrical energy, have attracted more attention in recent years. It is a device that uses microorganisms as catalysts to convert chemical energy into electrical energy. Microorganisms can metabolize organic substances and generate electrical energy at the same time. However, existing microbial fuel cells generally have the disadvantage of low power production; at the same time, the anode surface area in the existing technology is generally small, which is not conducive to the attachment of a large number of microorganisms, and the catalytic efficiency is narrowly applicable; in the existing technology, platinum is mostly used as the Although the cathode catalyst has good catalytic effect, it is too expensive. There is research to develop a microbial fuel cell based on 2,6-di-tert-butylpyridine medium, including a reactor arranged in a shell and a battery positive electrode and a battery negative electrode arranged outside the shell. The bottom of the battery positive electrode is connected to the reaction One end of the reactor; the bottom of the negative electrode of the battery is connected to the other end of the reactor. The microbial fuel cell based on 2,6-di-tert-butylpyridine medium of the present invention has a large electrode surface activation area, increases the electrostatic interaction between microorganisms and the electrode surface, increases microbial adsorption, and has good catalytic performance, thereby improving power output and reduce production costs.
2,6-di-tert-butylpyridine can also be used to prepare a ceramic mobile phone case with micro-arc oxidation of the metal surface, including a metal alloy case and a ceramic film layer applied to the outer surface of the case through micro-arc oxidation. The raw materials for preparing the ceramic film layer include, in parts by weight: 5-10 parts of dimethyl sulfoxide, 1-2 parts of potassium hydroxide, 0.5-1 part of ammonium chloride, and 0.1-1 part of citric acid. , 0.5-1 part of barium carbonate, 1-2 parts of zirconia powder, 5-10 parts of 2-hydroxy-2-methylphenylpropan-1-one, 0.5-1 part of 2,6-di-tert. Butylpyridine and 5-10 parts of sulfonated polyphosphazene-polyvinyl alcohol-nano-hydroxyapatite composite and 100 parts by weight of water. The obtained ceramic mobile phone case with micro-arc oxidation on the metal surface has good mechanical strength and durability, and overcomes the shortcomings of the existing technology.
