m-Xylene
Solvent Versatility: This compound demonstrates complete miscibility with numerous organic solvents, supporting its application across diverse chemical processing operations.
Industrial Intermediate Function: It serves as a critical precursor in the synthesis of key industrial chemicals including phthalic anhydride, isophthalic acid, and terephthalic acid.
Thermal and Flammability Properties: Characterized by a low melting point of -48°C and flash point of 25°C, the material maintains functionality in cryogenic applications while requiring strict flammability controls.
Stability and Safety Metrics: With an autoignition temperature of 528°C and established exposure thresholds, the compound can be safely managed in industrial settings when proper handling protocols are implemented.
Xylene exists as a colorless flammable liquid comprising three structural isomers: ortho-, meta-, and para-xylene. These isomers exhibit distinct melting points at -25.2°C, -47.9°C, and 13.3°C respectively, with corresponding boiling points at 144.4°C, 139.1°C, and 138.3°C. Their relative densities measure 0.8802, 0.8642, and 0.8611 respectively. While demonstrating negligible aqueous solubility, xylene achieves complete miscibility with diverse organic solvents. Through successive catalytic oxidation processes, it undergoes conversion to phthalic anhydride, isophthalic acid, and terephthalic acid.
Parameters
Melting point | -48 °C (lit.) |
Boiling point | 138-139 °C (lit.) |
density | 0.868 g/mL at 25 °C (lit.) |
vapor density | 3.7 (vs air) |
vapor pressure | 16 mm Hg ( 37.7 °C) |
refractive index | n20/D 1.497(lit.) |
Fp | 77 °F |
storage temp. | 2-8°C |
solubility | Miscible with many organic solvents, including alcohol and ether |
form | Liquid |
pka | >15 (Christensen et al., 1975) |
color | Colorless |
Odor | Like benzene; characteristic aromatic. |
Odor Threshold | 0.041ppm |
explosive limit | 1.1-7%(V) |
Water Solubility | Miscible with organic solvents. Immiscible with water. |
Merck | 14,10081 |
BRN | 605441 |
Henry's Law Constant | 14.80 at 45.00 °C, 17.26.4 at 50.00 °C, 19.90 at 55.00 °C, 23.01.3 at 60.00 °C, 27.46.3 at 70.00 °C (static headspace-GC, Park et al., 2004) |
Dielectric constant | 2.3999999999999999 |
Exposure limits | NIOSH REL: 100 ppm (435 mg/m3), STEL 150 ppm (655 mg/m3), IDLH 900 ppm; OSHA PEL: TWA 100 ppm; ACGIH TLV: TWA 100 ppm, STEL 150 ppm (adopted). |
InChIKey | IVSZLXZYQVIEFR-UHFFFAOYSA-N |
LogP | 3.16 at 20℃ |
Surface tension | 28.47mN/m at 298.15K |
CAS DataBase Reference | 108-38-3(CAS DataBase Reference) |
NIST Chemistry Reference | Benzene, 1,3-dimethyl-(108-38-3) |
EPA Substance Registry System | m-Xylene (108-38-3) |
Safety Information
Hazard Codes | Xn,T,F |
Risk Statements | 10-20/21-38-39/23/24/25-23/24/25-11-36/38 |
Safety Statements | 25-45-36/37-16-7 |
RIDADR | UN 1307 3/PG 3 |
OEB | A |
OEL | TWA: 100 ppm (435 mg/m3), STEL: 150 ppm (655 mg/m3) |
WGK Germany | 2 |
RTECS | ZE2275000 |
Autoignition Temperature | 982 °F |
TSCA | Yes |
HazardClass | 3 |
PackingGroup | II |
HS Code | 29024200 |
Hazardous Substances Data | 108-38-3(Hazardous Substances Data) |
Toxicity | LD50 orally in rats: 7.71 ml/kg (Smyth) |
