Ethyleneamine series products refer to acyclic polymer products of ethylenediamine, such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, etc., and cyclic amines such as piperazine, ammonia ethylamine, etc. Basepiperazine, hydroxyethylpiperazine, etc.
The physical properties of several common vinylamine products are introduced below:
Product Usage
Low molecular weight polyamide resin(All high-carbon vinylamines in the vinylamine series can produce low-molecular-weight polyamide resins—low-molecular-weight polyamide resins are polycondensed from dimer acid and diamine or ethylene polyamine)
Pesticide(Ethyleneamine is mainly used in the production of dithiocarbamate fungicides in pesticides)
Medicine(Mainly used in the production of aminophylline, metronidazole, etc., mostly traditional medicines)
Surfactant(Polyethylene polyamine and fatty acid can be made into various cationic surfactants, which are used in shampoo, textile softener and other industrial fields)
Lubricant additives（Polymethacrylimide can be produced by reacting tetraethylenepentamine, triethylenetetramine and other distillation bottoms with polyisobutylene succinic anhydride, which can be used as ashless dispersive detergent additive in automobile oil)
Paper wet strength agent(Polyamide-epichlorohydrin resin PPE produced from diethylenetriamine or polyamide and epichlorohydrin is an important wet strength agent for papermaking)
Epoxy curing agent(The epoxy resin curing agent prepared by modification of vinylamine can be widely used in various adhesives, sealants, small castings, laminated materials and room temperature curing coatings, etc. The characteristics of vinylamine used in epoxy resin curing agents: Vinylamine is a low-viscosity liquid, which can be well miscible in epoxy resin; vinylamine can be cured at room temperature, and the process is convenient; the multifunctional amino group in vinylamine has no steric hindrance and has high reactivity; vinylamine reacts freely heat to speed up curing)
Spandex polymerization(Diethylenetriamine plays an important role in the spandex polymerization reaction as a metal chelating agent or cross-linking agent. EDTA contains amino functional groups, and the lone pair of electrons on the nitrogen atom has a certain ability to chelate metal ions, which can clathrate metal ions into Inside diethylenetriamine, it becomes a stable compound, thereby preventing metal ions from acting. Therefore, DETA can be used as a metal chelating agent in spandex, also known as a viscosity stabilizer. When extending the chain, use EDA, PDA and A small amount of DETA is a mixed chain extender. By adding DETA, a cross-linking agent with three functional groups, the chemical cross-linking points inside the spandex molecule are increased to make up for the use of asymmetric amines such as 1,2-propylenediamine (PDA). Causes the decline of spandex strength and heat resistance. In addition, adding DETA to diamine or diol chain extender helps to control the viscosity of the polymer, so that the purpose of increasing the spinning speed can be achieved by increasing the polymer concentration. DETA cross-links polymers to form a branched chain structure between polymers, which can prevent the formation of hydrogen bonds between polymer molecules, so it can effectively inhibit the subsequent viscosity increase of the polymerization stock solution, and can appropriately increase the concentration of the stock solution for polyurethane elastic fiber production and stability.)
Other aspects(Vinylamine can also be used in organic synthesis, synthetic rubber accelerator, soil conditioner, and in the identification and determination of metals)
Synthetic Pathway
There are mainly two synthetic routes of vinylamine, namely dichloroethane method and ethanolamine method.
The dichloroethane method is usually produced by the direct reaction of dichloroethane and ammonia liquid phase under high pressure without using a catalyst, and the single-pass yield of ethylenediamine is between 40% and 70%. The main reactions are as follows:
Ⅰ：CICH2CH2Cl +2NH3→NH2CH2CH2NH2·2HCI
Ⅱ：CICH2CH2CI + NH2CH2CH2NH2·2HCI+ 2NH3→ NH4CI+ NH2CH2CH2NHCH2CH2NH2·3HCI
Ⅲ：CICH2CH2CI +NH3→CICH=CH2+ NH4CI
The ammonification reaction of dichloroethane is a fast and exothermic reaction, and the main product ethylenediamine is an intermediate product of a series of reactions. The ethylenediamine produced by the reaction is more basic than inorganic ammonia, so it will continue to react with dichloroethane to form Diethylenetriamine (DETA), triethylenetetramine (TETA) and other polyethylene polyamines.
The advantage of the dichloroethane method is that the raw materials are easy to obtain, no catalyst is needed, and the by-products such as polyethylene polyamine and piperazine are high value-added substances, which are an important industrial production method of ethylene amine abroad. Companies such as AKZO in Sweden, Delamine in Holland and Tosoh in Japan adopt this method for production.
The ethanolamine method is divided into reductive amination process and condensation process. The corresponding catalysts are also divided into two types according to their reaction mechanism. One is reductive amination catalyst, which mainly uses metals or metal oxides of Group VIIIB and Group IB as catalyst active components. , and the other is a solid acid condensation catalyst, which mainly uses Lewis acid, protonic acid, heteropoly acid and molecular sieve as active components. The method of producing ethylenediamine by using ethanolamine and ammonia as raw materials with solid acid catalyst has the advantages of low reaction pressure, high product yield and low pollution, and is gradually becoming the trend of future development.
