m-Xylene

m-Xylene
Names
Other names
m-Xylol
1,3-Dimethylbenzene
Identifiers
108-38-3 Yes
ChEBI CHEBI:28488 
ChEMBL ChEMBL286727 
ChemSpider 7641 Yes
Jmol-3D images Image
Image
KEGG C07208 
PubChem 7929
RTECS number ZE2275000
UNII O9XS864HTE 
Properties
C8H10
Molar mass 106.16 g/mol
Appearance Colorless liquid
Density 0.86 g/mL
Melting point −48 °C (−54 °F; 225 K)
Boiling point 139 °C (282 °F; 412 K)
insoluble
Solubility in ethanol very soluble
Solubility in diethyl ether very soluble
1.49722
Viscosity 0.8059 cP at 0 °C
0.6200 cP at 20 °C
Dipole moment 0.33-0.37 D[1]
Hazards
MSDS External MSDS
Main hazards Harmful or fatal if swallowed. Vapor harmful. Flammable liquid and vapor.
R-phrases R10 R20 R21 R38
S-phrases S25
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline) Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
3
1
0
Flash point 25 °C
Explosive limits 1.1%-7.0%[2]
US health exposure limits (NIOSH):
TWA 100 ppm (435 mg/m3)[2]
Related compounds
benzene
toluene
o-xylene
p-xylene
Supplementary data page
Refractive index (n),
Dielectric constant (εr), etc.
Thermodynamic
data
 Phase behaviour
solid–liquid–gas
UV, IR, NMR, MS
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

m-Xylene (or meta-xylene) is an aromatic hydrocarbon, based on benzene with two methyl substituents. It is an isomer of o-xylene and p-xylene. The m stands for meta, meaning the two methyl substituents are at locants 1 and 3 on the aromatic ring. m-Xylene is commonly produced in BTX processes, and separated as needed from the other aromatic hydrocarbons.

The major chemical use of meta-xylene is in the manufacture of isophthalic acid, which is used as a copolymerizing monomer to alter the properties of polyethylene terephthalate (PET), making PET more suitable for the manufacture of soft drinks bottles. To convert m-xylene on an industrial scale to isophthalic acid, the two methyl groups are both catalytically oxidized to carboxyl groups. It is also used as a raw material in the manufacture of 2,4- and 2,6-xylidine as well as a range of smaller-volume chemicals.[3]

References

  1. ↑ DeanHandb, Lange´s Handbook of chemistry, 15th edition,1999.
  2. ↑ 2.0 2.1 "NIOSH Pocket Guide to Chemical Hazards #0669". National Institute for Occupational Safety and Health (NIOSH).
  3. ↑ Ashford's Dictionary of Industrial Chemicals, third edition, page 9692.