ISO 7270-1-2020 pdf download.Rubber一Analysis by pyrolytic gas- chromatographic methods一 Part 1: Identification of polymers (single polymers and polymer blends).
7.2.2 Pyrolysls device
The following types of electrically heated pyrolysis device are suitable:
7.2.2.1 Micro-furnace, with quartz tubes in which the test portion is pyrolysed.
7.2.2.2 Curie-point pyrolyser, with a holder (pyrolysis probe) containing ferromagnetic material which surrounds the test portion and is heated to the Curie-point temperature to pyrolyse the test portion.
7.2.2.3 Platinum-filament pyrolyser, with a holder (pyrolysis probe) containing a platinum filament which surrounds the test portion and is heated to pyrolyse the test portion.
7.2.3 Gas chromatograph
A wide variety of chromatographs using either a flame-ionization detector (FID) or a thermal conductivity detector (TCD) are suitable for use in this document.
Selective detectors such as electron capture detector (ECD), flame photometric detector (FPD), flame thermionic detector (FTD), atomic emission detector (AED) can give useful information. For identification of pyrolysis products, a mass spectrometer detector can be utilized.
7.2.4 Chromatographic columns
A variety of column lengths and diameters and stationary and liquid phases are suitable for use in this
document, the main requirement being good resolution of the volatile pyrolysis products. NOTE 1 Capillary columns with good separation efficiency are suitable, but not essential.
NOTE 2 Capillary columns containing non-polar polydimethylsiloxanes and partially modified (diphenyl-, cyanopropylphenyl- or other) semi-polar silicones are suitable.
NOTE 3 Usually, capillary columns require little evaluation, while it often is necessary to evaluate many conditions for polar and non-polar packed columns.
The conditions chosen will depend on the column used. 1’pical operating conditions for the gas chromatograph with both polar and non-polar columns can be found in Tahk.U. to £ Typical pyrograms obtained can be found in Figures 1 to 44.
7.2.5 Data-handling equipment
A recorder, an integrator or a computer data-analysis system may be used.
8 Procedure
8.1 Accurate comparison of the pyrogram of an unknown polymer with the reference is only possible under the same conditions.
8.2 Extraction of test samples is recommended to remove additives which may interfere with the chromatographic separation. For oil-extended materials, extraction of the extender oil is essential otherwise this oil may cause serious interference in the pyrogram. Carry out the extraction following the general principles of either method A or method B in ISO 1407:201 1. The chosen solvent shall not affect the polymer and shall remove as much of the additives as possible. After extraction, dry the test sample, as residual solvent may cause interference with the pyrolysis products (see 9A).
8.3 Take a test portion of mass appropriate to the apparatus used. Generally, this will be between 0.1 mg to S mg. For good reproducibility, the size of the test portion should be as small as practicable.ISO 7270-1 pdf download.