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Ethylene Glycols
What Are ethylene glycols?
Mono -, di- and triethylene glycols are the first three members of a homologous series of dihydroxyalcohols.
They are colourless,
essentially
odourless stable liquids with low viscosities and high boiling are due mainly
to variations in physical properties
such as viscosity, hygroscopicity and boiling point.
Most ethylene glycol (EG) is produced by the direct hydration of ethylene oxide. Smaller amounts of diethylene
glycol(DEG) and
triethylene glycol(TEG) are co - produced in this process.
Additional quantities of Deg and TEG can be produced by reacting EG with additional ethylene oxide.
How are ethylene glycols used?
Glycols are widely used in industry because of their high boiling points, hygroscopicity, non-corrosiveness,
freeze point
depression, lubricating, plasticising and solvent properties. In addition, their ease of chemical
reaction, due to their alcohol
end groups, makes them popular intermediates in the formation of numerous esters.
In each application, the specific balance
of properties required will determine the particular lycol to be used.
More specifically, this is how each of the ethylene glycols used:
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Ethylene Glycol
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Property
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Units
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Test Method
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Value
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Purity
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wt %
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ASTM D-2693
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99.8 min.
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Diethylene Glycol
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wt %
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ASTM D-2693
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0.080 max.
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Water Content
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wt %
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ASTM D-1364
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0.08 max.
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Acidity (As Acetic Acid)
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wt.ppm
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ASTM D-1613
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10 max
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Ash
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gr/100 ml
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ASTM D-1506
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0.005 max.
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Chlorides
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wt.ppm
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EO - 635
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0.01 max.
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Aldehyde (As Fomaldehyde)
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wt.ppm
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DC - 163 C
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8 max.
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Color, Pt-Co Scale
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---
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ASTM D-1209
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5 max.
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Sp.Gr.@ (20 /20 oC) |
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---
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ASTM D-891
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1.1151-1.1156
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Distillation @ 760 mmHg I.B.P |
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I.B.P |
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ASTM D-850 |
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242 min. |
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Distillation @ 760 mmHg D.P |
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I.B.P |
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ASTM D-850 |
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250 max. |
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5-95 vol% Range
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°C
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ASTM D-1078
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1 max.
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Odour
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--- |
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ASTM E-1075/D-2693
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mild
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Suspended
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--- |
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---
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None
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Iron
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°wt.ppm
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ASTM E-202
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0.1 max.
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UV Transmittance: AT
220 NM AT 275
NM AT 350 NM
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--- |
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ASTM E-1176
ASTM E-1176
ASTM E-1176
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70 min.
95 min.
99 min.
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Diethylene Glycol
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Property |
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Units |
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Test Method |
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Value |
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Purity |
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wt % |
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ASTM D-2694 |
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99.8 min. |
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Monoethylene Glycol |
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wt % |
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ASTM D-4291 |
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0.05 max. |
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Triethylene Glycol |
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wt % |
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ASTM E-202 |
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0.05 max. |
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Water Content |
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wt.ppm |
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ASTM D-1364 |
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0.05 max. |
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Acidity (As Acetic Acid) |
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wt % |
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ASTM D-1613 |
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0.005 max. |
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Ash Content |
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wt % |
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ASTM E-347 |
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0.005 max |
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Sp.Gr.@ (20 /20 oC) |
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--- |
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ASTM D-891 |
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1.1175-1.1195 |
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Distillation @ 760 mmHg I.B.P |
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I.B.P |
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ASTM D-1078 |
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242 min. |
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Distillation @ 760 mmHg D.P |
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I.B.P |
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ASTM D-1078 |
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250 max. |
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5-95 vol% Range |
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°C |
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ASTM D-1078 |
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1 max. |
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