ASTM D 3452 : 1993 : R1998

1.1 This practice is a guide to the identification of polymers in raw rubbers, and cured and uncured compounds, based on a single polymer, by the gas chromatographic patterns of their pyrolysis products (pyrograms). Implementation of this guide presupposes a working knowledge of the principles and techniques of gas chromatography, sufficient to carry out this practice and to interpret the results correctly.

1.2 This practice will identify the following polymers:

1.2.1 Polyisoprene of natural or synthetic origin,

1.2.2 Butadiene-styrene copolymers,

1.2.3 Polybutadiene,

1.2.4 Polychloroprene,

1.2.5 Butadiene-acrylonitrile copolymers,

1.2.6 Ethylene-propylene copolymers and related ter- polymers, and

1.2.7 Isobutene-isoprene copolymers.

1.3 This practice will not differentiate the following polymers:

1.3.1 Natural polyisoprene from synthetic polyisoprene.

1.3.2 Butadiene-styrene copolymers produced by solution and emulsion polymerization. It is sometimes possible to distinguish butadiene-styrene copolymers containing different amounts of styrene as well as random polymers from block polymers.

1.3.3 Polybutadiene with different microstructures.

1.3.4 Different types of polychloroprenes.

1.3.5 Butadiene-acrylonitrile copolymers with different monomer ratios.

1.3.6 Ethylene-propylene copolymers with different monomer ratios, as well as the copolymers from the related terpolymers.

1.3.7 Isobutene-isoprene copolymers (butyl rubbers) from halogenated butyl rubbers.

1.3.8 Polyisoprene containing different amounts of cistrans isomers.

1.3.9 The practice does not identify ebonite or hard rubbers.

1.4 The values stated in SI units are to be regarded as the standard.

1.5 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.