diisopropenylbenzene is a monomer that can be used in the preparation of many useful polymers and is also a chemical intermediate that can be employed in a number of chemical processes . diisopropenylbenzene is normally synthesized by the dehydrogenation of diisopropylbenzene . unfortunately in this dehydrogenation process a number of olefinic impurities are produced as by - products . this invention discloses a process for the separation of diisopropenylbenzene from these impurities and for recycling some of the impurities . in one embodiment of this invention this process comprises : dehydrogenating diisopropylbenzene to form a dehydrogenation mixture containing diisopropenylbenzene and organic impurities , continuously distilling said dehydrogenation mixture to separate said diisopropenylbenzene from said organic impurities , fully hydrogenating said organic impurities to form a mixture of regenerated diisopropylbenzene and saturated organic impurities , and fractionally distilling said mixture of regenerated diisopropylbenzene and saturated organic impurities under conditions sufficient to separate said regenerated diisopropylbenzene from said saturated organic impurities . the regenerated diisopropylbenzene can then be recycled for dehydrogenation with fresh diisopropylbenzene in the first step of the above described process .