rubber in accordance with this invention however the halogen will normally be selected from the group consisting of fluorine chlorine bromine and iodine chlorine and bromine are preferred with bromine being more preferred after the appropriate amount of the halogen is added to the rubber cement the rubber cement will normally be agitated in order to ensure that there is adequate mixing the halogen will readily react with the high vinyl polybutadiene in the rubber cement over a very wide temperature range as a matter of convenience a temperature within the range of about 0 u00b0 c to about 100 u00b0 c will normally be utilized in most cases the halogenation will be carried out at room temperature which is typically within the range of about 20 u00b0 c to about 25 u00b0 c it is not necessary to utilize a catalyst in order to carry out the halogenation reaction after the high vinyl polybutadiene has been halogenated it can be recovered from the rubber cement utilizing standard techniques for instance the halogenated high vinyl polybutadiene can be precipitated from the rubber cement the halogenated high vinyl polybutadiene rubber can also be recovered from the organic solvent and residue by decantation filtration.