1、Computational study on the mechanism and kinetics of Cl
Two reaction types (Cl-addition and H-abstraction) and the subsequent reactions for the primary intermediates (IM1 and IM2) have been proposed in the presence of O 2 and NO. The calculated results show that the Cl addition–elimination mechanism dominates the reaction between vinyl acetate and Cl.
2、Vinyl Acetate
Vinyl acetate is used in the production of a wide range of polymers, including polyvinyl acetate, polyvinyl alcohol, polyvinyl acetals, ethylene–vinyl acetate copolymers and polyvinyl chloride–vinyl acetate copolymers, which are widely used in the production of adhesives, paints and food packaging.
3、Introduction to the production process of vinyl acetate
Vinyl acetate monomer (VAM) is flammable and reacts rapidly with chlorine, bromine, and ozone. There are two production process routes for vinyl acetate monomer: the ethylene method and the acetylene method.
4、Chlorination of vinylacetate to form Chloroacetaldehyde
Chlorine is first added to vinylacetate at room temperature with cooling to form 1,2-dichlororethylacetate, which is then hydrolyzed at 50-60°C to form chloroacetaldehyde.
Kinetic study of the gas
Kinetic study of the gas-phase reaction of atomic chlorine with a series of acetates K. Hemavibool, T. Malkin, P. Seakins, A. Goddard, D. Glowacki, M. Pilling, and D. Heard University of Leeds, Leeds, LS2 9JT, UK. chmkhe@leeds.ac.uk
Chapter 9. Reactions of vinyl polymers
Reaction between appropriate difunctional or polyfunctional reagents with labile groups on the polymer chains Polymers containing acid chloride groups react with diamine (9.40), or diols (9.41) to yield sulfonamide and sulfonate crosslinks
10 Vinyl Acetate Monomer Process
+ 2 O (10.1) Gas - phase reaction is preferred because of better yield and less corrosion problems.
Synthetic Features and Mechanism for the Preparation of Vinyl Chloride
Without any type of surfactant or dispersing agent, precipitation polymerization has great superiorities in both polymer synthesis and applications.
Computational study on the mechanism and kinetics of Cl
Two reaction types (Cl-addition and H-abstraction) and the subsequent reactions for the primary intermediates (IM1 and IM2) have been proposed in the presence of O 2 and NO. The calculated results show that the Cl addition–elimination mechanism dominates the reaction between vinyl acetate and Cl.
Vinyl Chloride
Vinyl chloride-vinyl acetate copolymers are defined as polymers formed by the copolymerization of vinyl chloride and vinyl acetate, notable for their applications in the plastics industry.
In the field of chemistry, chemical reactions serve as the driving force behind scientific advancement. Among them, chlorination reactions in organic synthesis have garnered significant attention due to their widespread applications and complexity. Vinyl acetate (VAc), an unsaturated carboxylic acid with a double bond in its molecular structure, is an ideal candidate for studying chlorination reactions. This article explores the reaction process, products, and applications of vinyl acetate with chlorine gas.
I. Chemical Reaction Principles
Vinyl acetate is an unsaturated carboxylic acid containing a carbon-carbon double bond and a carboxyl group. When vinyl acetate reacts with chlorine gas, chlorine atoms substitute hydrogen atoms on the double bond, forming chloroethyl acetate. This reaction follows a free radical chain mechanism: a chlorine atom abstracts a hydrogen atom from the double bond, generating a free radical. These radicals collide and propagate the reaction, sustaining the chain process.
II. Experimental Methods
To investigate the reaction between vinyl acetate and chlorine gas, scientists employ various experimental approaches. A classic method involves thin-layer chromatography (TLC) to monitor reaction progress. A thin layer of vinyl acetate solution is applied to a TLC plate, and chlorine gas is introduced through a narrow gap above the plate. As chlorination proceeds, products leave distinct color spots on the plate. The size and position of these spots indicate reaction progress and product types.
In addition to TLC, modern analytical techniques such as infrared (IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy are used to study the reaction. These methods offer higher sensitivity and resolution, providing deeper insights into reaction mechanisms and product structures.
III. Product Analysis
The primary products of the reaction between vinyl acetate and chlorine gas include chloroethyl acetate and potential byproducts. Chloroethyl acetate forms via hydrogen substitution by chlorine atoms. Byproducts like hydrogen chloride (HCl), dichloroacetic acid, and trichloroacetic acid may arise due to chlorine atom disproportionation or reaction condition variations.
Analyzing these products helps elucidate reaction mechanisms and properties. Techniques like IR and NMR confirm product structures, while properties such as yield and selectivity assess reaction efficiency and chlorine gas usage.
IV. Practical Applications
The chlorination of vinyl acetate holds industrial significance. Chloroethylene, a key monomer, is widely used in plastics, rubber, coatings, and adhesives. By chlorinating vinyl acetate, its value is maximized. Chloroethylene can also react with other chemicals to produce useful compounds like chloroprene rubber and chlorohydrin rubber.
chlorination poses risks. Chlorine gas is toxic at high concentrations, necessitating protective measures for worker safety. Additionally, byproducts may pollute the environment, requiring strict environmental controls during production.
The chlorination of vinyl acetate with chlorine gas is a complex process involving free radical chain mechanisms and advanced analytical techniques. Studying this reaction enhances our understanding of vinyl acetate’s properties and guides industrial applications. Concurrently, addressing risks like toxicity and environmental impact remains critical to ensure safe and sustainable practices.
