It is well known that polyolefins, styrene polymers and engineering plastics occupy the largest share of the plastic market and constitute nearly 80% of the world's plastic. However, these plastics are usually used or recycled in mixed state and immiscible with each other. It is hard to define or separate these plastics, respectively, from recycled materials. In this letter, a maleic anhydride (MAH) and styrene (St) dual monomers grafted poly [styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS), SEBS-g-(MAH-co-St) was developed as a multi-functionalized compatibilizer for combining engineering plastics, styrene polymers and polyolefins. With the help of the compatibilizer, the model quaternary blend PA6/PS/PP/ SEBS (70/10/10/10) transforms from brittle into tough blends, and shows controllable morphologies and significantly improved mechanical properties. This highly efficient compatibilization strategy casts new light on both the development of high-performance multi-phase polymer blends and the recycling of waste plastics. (C) 2017 Elsevier Ltd. All rights reserved.