General Information:
Inhibited glycol or propylene glycol is an organic double alcohol with a chemical formula of C3H8O2 and a CAS number of 57-55-6. Its official IUPAC name is propane-1,2-diol. It is a thick, clear, and nearly odorless substance with a faintly sweet taste. Propylene glycol shares similarities with glycerin - hygroscopic, soluble with water, acetone, and chloroform.
Physical Properties:
Inhibited glycol or propylene glycol is an organic double alcohol with a chemical formula of C3H8O2 and a CAS number of 57-55-6. Its official IUPAC name is propane-1,2-diol. It is a thick, clear, and nearly odorless substance with a faintly sweet taste. Propylene glycol shares similarities with glycerin - hygroscopic, soluble with water, acetone, and chloroform.
Physical Properties:
Molecular mass: 76.10 g/mol
Melting point: -59° C
Boiling point: 187.6° C
Vapor pressure: 0.2 (23° C)
Vapor density: 2.62 (air=1)
Viscosity: 91.41 cp (10.45° C)
Surface tension: 40.1 g/s2 (25° C)
Refractive index: 1.4324 (20° C)
Heat of vaporization: 66.27 kJ/mol
Heat of combustion: -1828 kJ/mol
Manufacturing Process:
Propylene glycol is usually sourced from propylene oxide or glycerol. Manufacturing is done by either catalytic (150°-180°C) or non-catalytic high-temperature process (200°-220°C), with an ion exchange resin or a small amount of sulfuric acid or alkali. Final products include 20% propylene glycol, 1.5% dipropylene glycol, and other polypropylene glycols. Then, resulting glycols are further distilled to be purified prior to storage and distribution. To assure high quality and compliance with the FDA standards, a track-and-trace system is used to monitor the start of the process up to the delivery point.
References:
Wikipedia - http://en.wikipedia.org/wiki/Propylene_glycol
University of Akron Chemical Database - http://ull.chemistry.uakron.edu/erd/Chemicals/8000/
7709.html
Cefic - http://www.propylene-glycol.com/production.html
Melting point: -59° C
Boiling point: 187.6° C
Vapor pressure: 0.2 (23° C)
Vapor density: 2.62 (air=1)
Viscosity: 91.41 cp (10.45° C)
Surface tension: 40.1 g/s2 (25° C)
Refractive index: 1.4324 (20° C)
Heat of vaporization: 66.27 kJ/mol
Heat of combustion: -1828 kJ/mol
Manufacturing Process:
Propylene glycol is usually sourced from propylene oxide or glycerol. Manufacturing is done by either catalytic (150°-180°C) or non-catalytic high-temperature process (200°-220°C), with an ion exchange resin or a small amount of sulfuric acid or alkali. Final products include 20% propylene glycol, 1.5% dipropylene glycol, and other polypropylene glycols. Then, resulting glycols are further distilled to be purified prior to storage and distribution. To assure high quality and compliance with the FDA standards, a track-and-trace system is used to monitor the start of the process up to the delivery point.
References:
Wikipedia - http://en.wikipedia.org/wiki/Propylene_glycol
University of Akron Chemical Database - http://ull.chemistry.uakron.edu/erd/Chemicals/8000/
7709.html
Cefic - http://www.propylene-glycol.com/production.html