Ethyl cyanoacrylate
| Names | |
|---|---|
| IUPAC name
Ethyl 2-cyanoprop-2-enoate
| |
| Other names
2-Cyano-2-propenoic acid ethyl ester
ECA Ethyl 2-cyanoacrylate ethyl a-cyanoacrylate Krazy glue Super glue | |
| Properties | |
| C6H7NO2 H2C=C(CN)-C(O)O-C2H5 | |
| Molar mass | 125.127 g/mol |
| Appearance | Colorless viscous liquid |
| Odor | Sweet, irritant |
| Density | 1.06 g/cm3 (20 °C) |
| Melting point | −22 °C (−8 °F; 251 K) |
| Boiling point | 214 °C (417 °F; 487 K) 55 °C (131 °F; 328 K) (at 3 mmHg) |
| Reacts | |
| Solubility | Miscible with acetone, dichloromethane, dimethylformamide, methyl ethyl ketone, nitromethane |
| Vapor pressure | 0.31 mmHg at 20 °C |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | 83 °C (181 °F; 356 K) |
| Lethal dose or concentration (LD, LC): | |
| LD50 (Median dose)
|
5000 mg/kg (rat, oral) |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Ethyl cyanoacrylate (ECA), is an organic compound, the ethyl ester of 2-cyano-acrylic acid. It is the main component of cyanoacrylate glues and can be encountered under many trade names, like Super glue.
Contents
Properties
Chemical
Ethyl cyanoacrylate polymerizes in the presence of moisture or weakly basic compounds, property which allows it to be used in bonding. The reaction is very exothermic, and under the right circumstances it may even ignite materials with a very low flash point.
Physical
Ethyl cyanoacrylate is a colorless viscous liquid, which reacts with water, causing polymerization, but it's miscible with a variety of other solvents, like ketones and halocarbons, and the solutions are stable in the absence of moisture.
Availability
Ethyl cyanoacrylate can be bought from most hardware stored, as superglue. In general, the product contains nearly pure ethyl cyanoacrylate, though some brands may contain additional compounds or other additives. Coloring is rarely present.
Preparation
Ethyl cyanoacrylate is prepared by the condensation of formaldehyde with ethyl cyanoacetate (which in turn can be prepared from ethyl chloroacetate and sodium cyanide via Kolbe nitrile synthesis):
- NC-CH2CO2C2H5 + CH2O → H2C=C(CN)CO2C2H5 + H2O
This exothermic reaction yields the polymer (due to the presence of water), which is subsequently sintered and thermally cracked to give the monomer.
Another route involves the ethoxycarbonylation of cyanoacetylene.[1]
Projects
- Start fire
- Make superglue
- Recover fingerprints
- Liquid bandage for wounds
- Make really tough materials from paper and superglue
Handling
Safety
Ethyl cyanoacrylate has low toxicity, though its setting reaction is highly exothermic, and may even cause light burns in large amounts. It is extremely sticky, and will bond materials very tightly, even different materials. Acetone or MEK can be used to dissolve the bonds, in the event one accidentally glues themselves.
Due to its low toxicity, it may be used in liquid bondage in first aid kids, to seal wounds, though 2-octyl cyanoacrylate is usually preferred, as it's even less toxic.
Though it contains a nitrile group, ethyl cyanoacrylate produces very little hydrogen cyanide during its decomposition, thus there is no risk or cyanide poisoning in the event of accidentally ingesting this compound or its polymer. The fumes produced from the setting reaction are irritant to the lungs, eyes and nose, as they tend to contain unreacted ethyl cyanoacrylate, that deposits on the surface of the tissue and polymerizes. This property is exploited in recovering fingerprints from various items.
Storage
Must be kept in airtight containers, away from any moisture. Sometimes, polymer inhibitors may be added.
Disposal
No special disposal is required. May be dumped in trash or burned.
References
- ↑ Ohara, Takashi; Sato, Takahisa; Shimizu, Noboru; Prescher, Günter; Schwind, Helmut; Weiberg, Otto; Marten, Klaus; Greim, Helmut; Shaffer (2020). "Acrylic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. pp. 1–21
