1.1 This International Standard specifies a method for the determination of polyisoprene occurring as natural isoprene rubber (NR) *), synthetic isoprene rubber (IR), balata and gutta percha, in the total solids from NR or IR latices, in solid raw rubbers, or in cured or uncured compounds.
The method is applicable to these isoprene rubbers alone or in blends. It cannot be used for hard rubber (ebonite) without modification.
1.2 Compounding ingredients, such as carbon black, mineral oil and sulfur, in soft rubbers do not interfere (see table 1) (but see also 8.2). If vinyl acetate polymers are present, the method should not be used.
*) For the meanings of the abbreviations, see ISO 1629:1987, Rubbers and latices - Nomenclature.