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Hydrogenated poly-1-decene

Prepared at the 49th JECFA (1997)

SYNONYMS

Hydrogenated polydec-1-ene, Hydrogenated poly-a -olefin, PAO, INS No. 907

DEFINITION

Hydrogenated poly-1-decene is a mixture of isoparaffinic molecules of known structure, prepared by hydrogenation of mixtures of tri-, tetra- penta- and hexa-1-decenes.

C.A.S. number

68037-01-4

Chemical formula

C10nH20n+2, where n = 3 - 6

Formula weight

550 (average)

Assay

Not less than 99.5 % of hydrogenated poly-1-decene, having the following oligomer distribution:

C30: 16 - 35 %
C40: 42 - 61 %
C50: 12 - 23%
C60: 1 - 9 %

DESCRIPTION

Colourless, odourless, viscous liquid

FUNCTIONAL USES

Glazing agent, releasing agent

CHARACTERISTICS


IDENTIFICATION


Solubility

Insoluble in water; slightly soluble in ethanol; soluble in toluene

Burning

The product bums with bright flame and a paraffin like characteristic smell.

Viscosity

6 cSt (100°)
See description under TESTS

PURITY


Hydrogenated decene dimer


Not more than 0.5 % (calculated as C20-oligomer)
See METHOD OF ASSAY

Readily carbonisable substances


Passes test
See description under TESTS

Nickel

Not more than 1 mg/kg

Heavy metals

Not more than 10 mg/kg


Test 2 g of sample as directed in the Limit Test (Method II)

TESTS


IDENTIFICATION TESTS

Viscosity

Use the method as described in ASTM D 445 (American Society for Testing Materials)

PURITY TESTS


Readily carbonizable substances


Place 5 g of the sample in a glass-stoppered test tube that has previously been cleaned with a chromic acid cleaning solution, rinsed with water and dried in an oven (105°, 1h). Add 5 ml of sulfuric acid TS, and place in a boiling water bath. After the test tube has been in the bath for 30 sec, remove quickly, and while holding the stopper in place, give three vigorous vertical shakes over an amplitude of about 10 cm. Repeat every 30 sec. Do not keep the test tube out of the bath longer than 3 sec for each shaking period. At the end of 10 min from the time when first placed in the water bath, remove the test tube. The sample remains unchanged in colour, and the acid does not become darker than a very slight straw colour (Matching Fluid E, see General Methods). No black material occurs at the interface between the two layers.

METHOD OF ASSAY

Hydrogenated poly-1-decene, oligomer distribution and the content of hydrogenated decene dimer: Determine by gas-liquid chromatography using the following conditions:

Column:

Capillary column, 16 m x 0.53 mm

Column film:

Nonpolar (polydimethyldisiloxane) film, thickness 0.1 m m, e.g. OV-1, DB-1

Carrier gas:

Helium

Flow rate:

10 ml/min

Injector pressure:

1.5 psi at 35°, constant flow

Detector type:

FID

Column temperature:

35° -1 min - 5°/min - 50° - 12°/min -170° - 10°/min - 310°-45 min

Injection temperature:

35°

Sample size:

2 m l

Calibration:
Calibrate the instrument using a solution with known composition containing about 1.0 % of n-tetradecane, 1.0 % of n-hexadecane and 1.0 % of squalane (2,6,10,15,19,23-hexamethyl tetracosane) in pentane. The differences between peak areas of the compounds should be less than 10.0 % and the resolution between tetradecane and n-hexadecane should be between 2 and 5. Calculate the resolution (R) from the distance between n-tetradecane and n-hexadecane peaks at the peak maxima (d) and the width of the peaks at the baseline (Y): R = [2(d1 -d2)/(Y1 - Y2)].

Sample preparation:
Take a small amount of the sample into an automatic pipette. Place a drop of the sample in 1.00 ml of pentane, and mix well. Record the chromatogram for about 45 min.

Retention times:
The retention times for C20, C30, C40, C50 and C60 are usually about 10.5, 16, 20, 23 and 26 min.

Calculation:
Calculate the level of hydrogenated decene dimer and the oligomer distribution by the method of area percentages (area normalization).

Calculate the percentage of hydrogenated poly-1-decene in the sample taken by the formula:

100 A/T

where

A = the sum of peak areas for C30, C40, C50 and C60
T = the sum of all peak areas eluting in 45 min


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