Nowadays successful recycling of rubber waste has been one of the greatest challenges in waste management. Difficulties in mechanical recycling are especially caused by the variability of raw materials, therefore, a processing simply combining them usually results in end-products with poor mechanical stability. Drawbacks of mechanical recycling of mixed plastics and blends of plastics and rubbers can be overcome by application of compatibilizing additives. Taking the commercial types into account only a few general kinds are available and their effectiveness is hindered by the structure as it cannot be fitted to the chemical structures of plastics processed together. Our study has been addressed to give a comprehensive outlook into a rubber recycling process and successful application of compatibilizing strategies for improving mechanical performance of waste elastomer containing polypropylene. Investigations have been carried out on effective elastomer concentrations, meanwhile on elastomer ratios of various types to each other and on proper structures of compatibilizers. Various mechanical properties could be improved even by 44% due to experimental additives compared to uncompatibilized blends. Mechanical test results have been confirmed by SEM, rheology and FT-IR, to name some of them.