Synergistic Compatibilization of LDPE/PS/PA6 Ternary Blends by Combining Reactive and Non‐Reactive Compatibilizers

ABSTRACT Efficient recycling of mixed plastic waste remains challenging due to the intrinsic immiscibility of constituent polymers, which compromises mechanical performance. Here, a synergistic compatibilization strategy combining reactive maleic anhydride–grafted low‐density polyethylene (LDPE‐ g ‐MA) and non‐reactive styrene–ethylene–butadiene–styrene (SEBS) is demonstrated to enhance interfacial adhesion and mechanical properties of LDPE/PS/PA6 blends. The cooperative action of LDPE‐ g ‐MA and SEBS minimized mutual interference and improved compatibilization efficiency at both LDPE/PA6 and LDPE/PS interfaces. In the LDPE/PS/PA6 (40/30/30) blend, the bicontinuous LDPE/PS morphology with PA6 encapsulated in PS transformed into an LDPE matrix containing salami‐like core–shell domains with mixed PS/PA6 cores upon addition of 5 wt.% LDPE‐ g ‐MA and 5 wt.% SEBS. In the LDPE/PS/PA6 (70/15/15) blend, the PA6@PS domains evolved into distinct, refined salami‐like structures with inner PS cores and interfacial localized PA6 domains upon addition of 3 wt.% LDPE‐ g ‐MA and 3 wt.% SEBS, increasing notched impact strength from 3.3 to 18.2 kJ·m −2 . In the LDPE/PS/PA6 (15/15/70) blend, LDPE@PS core–shell domains converted to salami‐like PS@LDPE structures with 3 wt.% LDPE‐ g ‐MA and 4.5 wt.% SEBS, enhancing impact strength from 2.9 to 11.7 kJ·m −2 . This work offers an effective, industrially relevant route to tailor morphology and upgrade the performance of heterogeneous plastic waste toward sustainable recycling.