Facile preparation of SAN/NBR TPV with balanced stiffness-toughness via metal-ligand coordination-induced dynamic vulcanization and in situ interfacial compatibilization

In this work, metal-ligand coordination interaction was utilized to induce the dynamic vulcanization (DV) of styrene-acrylonitrile copolymer (SAN)/butadiene acrylonitrile rubber (NBR)/cupric sulfate (CuSO4) TPVs. The TPVs exhibited co-continuous structure, in which the CuSO4 particles distributed in continuous NBR network to cross-link NBR phase through interaction between Cu2+ and nitrile groups (-CN), enhancing the mechanical strength and thickness of NBR network. CuSO4 particles were refined to nanoparticles during DV, and then migrated to SAN/NBR interface and interacted with SAN and NBR simultaneously to realize in-situ compatibilization, resulting in efficient toughening of SAN without sacrificing its stiffness. With 20 phr CuSO4, the TPVs showed excellent impact toughness of 104.51 kJ/m2, which was 58 times that of the neat SAN. Meanwhile, the TPVs exhibited improved tensile strength, elongation at break, tensile toughness and Young's modulus, revealing the balanced stiffness-toughness properties of TPVs. We propose a feasible approach to fabricate high-performance TPVs, and it may expand the research scope of dynamic vulcanization. [Display omitted] •Metal coordination was innovatively utilized to initiate dynamic vulcanization.•CuSO4 acted as curing agent to cure the NBR continuous network.•CuSO4 acted as nano-sized compatibilizer to realize interfacial compatibilization.•The composites exhibited balanced stiffness-toughness properties.