This standard specifies two methods for the determination of volatilematter
content in raw rubbers by using a hot mill or an oven. The
methods are applicable to the determination of the volatile-matter content
in the “R” group of rubbers listed in ISO 1629. These are rubbers having
an unsaturated carbon chain, for example natural rubber and synthetic
rubbers derived at least partly from diolefins. The methods can also be
applicable to other raw rubbers, but in these cases it is necessary to
demonstrate that the change in mass is due solely to loss of actual
volatile matter and not to rubber degradation. The hot-mill method is not
applicable to natural rubber, to synthetic rubbers which are too difficult to
handle on a hot mill or to synthetic rubbers in powder or chip form. The
test methods do not necessarily give identical results. Therefore, in
cases of dispute, the oven method, procedure A, is the reference
method.