BS ISO 7270-1-2020 Rubber一Analysis by pyrolytic gaschromatographic methods Part 1: Identification of polymers (single polymers and polymer blends).
7.22 Pyrolysls devce
The following types of elect ricaly heated pyrolysis device are suitablc
7.22.1 Micro-furnace, with quartz tubes in which the test portion is pymlysed.
7.2.22 Curie-point pyrulyser, with a holder (pyrolytic probel containing ferromagnetic material which surrounds the test portmn .ind is heated to the Cune-point temperature to pyrolyse the test portion.
7.22.3 Platlnum-Illansent pyrotyser, with a holder (pyrolysis probe) containing a platinum filament which surrounds the test portion .ind is htatrd to pyrolyse the test portion.
7.2.3 Gas chrornalograph
A wide variety of chrumatogr,iphs using eIther a Ilame•lomzation dctectuc (HD) or a thermal conductivity detector (TCD) are suitable for use in this documenc
Selective detectors such as electron capture detector (ECl). flame photometric detector (FPD). flame thermmmc detector (FTD). atomic emission detector (AEL)) can give useful information. For identification of pyrolysls products, a mass spectrometer detector can be utilized.
7.2.4 Chromatographfc column;
A variety of column lengths and diameters and stationary and liquid phases are suitable for use in this document, the nuin requirement being good resolution of the volatile pyrolysis products.
NOTE I Capillary cniumni with good separation c#ficicncy are imitable. but not essential
NOTE 2 CapIllary columns containing non-polar polydl.wtbyLsilosanes and partially modified (dlpiienyl.. cyannjwapylpiwnyi. or oilier) scmi.pnl.ar silicanes 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 colum.s.
The conditions chosen will depend on the column used. Typual operating conditions for the gas chromatograph with both polar and non-polar columns can be found In Tables Ito 5. Typical pyrograms obtained can hr found in Figines ito 44.
7.2.5 Data-handling equipment
A recorder, an Integrator or a computer data-analysis system may he used.
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 whicis may Interfere with the ctiromatographic separation. For oil extended materials, extraction of the extender oil is essential otherwise this oil may cause serious interference in the pyrograns- Carry out the extraction following the general pnnciples of either method A or method B In ISO 1407:2011. The chosen solvent shall not affect the polymer and shall remove as much of the additives as possible. Alter extraction, dry the test sample. is residual solvent may cause Interference with the pyrolysls prod uc’ts (lee 9_A).
8.3 Take a test portion of mass appropriate to the apparatus used Generally this will be between 0,1 mg to 5 mg. For good reproducibility, the size of the test portion should be as small as practicable.BS ISO 7270-1 pdf download.