BS ISO 7270‑1:2020 pdf download.Rubber — Analysis by pyrolytic gas- chromatographic methods.
WARNING 1 — Persons using this document should be familiar with normal laboratory practice. This document does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to determine the applicability of any other restrictions.
WARNING 2 — Certain procedures specified in this document might involve the use or generation of substances, or the generation of waste, that could constitute a local environmental hazard. Reference should be made to appropriate documentation on safe handling and disposal after use.
1 Scope
This document specifies a method for the identification of polymers, or blends of polymers, in raw rubbers and in vulcanized or unvulcanized compounds from pyrograms (pyrolysis-gas chromatographic patterns) obtained under the same conditions. This allows qualitative identification of single rubbers or blends, with exceptions discussed below. This document is not intended for quantitative analysis.
The method applies first and foremost to single polymers. When the pyrogram indicates a characteristic hydrocarbon, the method is also applicable to blends. For details, see Clause 5. The method can be also applicable to other types of polymer when verified by the analyst in each particular case.
NOTE The use of this document pre-supposes sufficient working knowledge of the principles and techniques of gas chromatography to enable the analyst to carry out the operations described and to interpret the results correctly.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments applies.
ISO 1407:2011, Rubber — Determination of solvent extract
ISO 1629:2013. Rubber and latices — Nomenclature
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and TEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:/fwww.iso.orgjobp
— IEC Electropedia: available at http://www.electropedia.org/
4 Principle
4.1 Raw or vulcanized rubbers and/or their blends are pyrolysed and the pyrolysis products are subjected to gas-chromatographic analysis under predefined conditions. The chromatograms produced are referred to as pyrograms.
4.2 Pyrograms are interpreted by comparison with reference pyrograms produced from the same rubbers and/or blends, prepared and analysed under the same conditions.
5 Single polymers and blends
5.1 General
The rubbers in the following listing are grouped in accordance with ISO 1629:2013.
5.2 GroupM
a) Chlorinated polyethylene (CM) and chiorosulfonated polyethylene (CSM).
NOTE I The pyrogram will not differentiate between these chlorinated polyethylenes.
b) Ethylene-propylene copolymers (EPMs) and ethylene-propylenc-dienc terpolymers (EPDMs).
NOTE 2 The pyrogram can differentiate terpolymers from copolymers when the pyrogram indicates characteristic clicne” monomer pyrolysis products.
c) Acrylic rubbers (ACMs).
5.3 Group 0
Epichlorohydrin rubbers [homopolymer (CO), copolymer (CO) and rerpolymersj.
NOTE The pyrogram will not differentiate between these various types of epichlorohydrin polymer.
5.4 GroupQ
Polysiloxanes.BS ISO 7270‑1 pdf download.