LAUSR

Polyamide/polyphenylene oxide (PA/PPO) blends represent high‐performance engineering thermoplastics, yet uncompatibilized systems suffer from poor mechanical properties and interfacial instability. While reactive compatibilizers address these issues, they often introduce residual monomers or processing sensitivity. Herein, we propose polystyrene‐graft‐polyamide 6 (PS‐g‐PA6) comb‐type copolymers as non‐reactive compatibilizers. Three variants of PS‐g‐PA6 comb‐type copolymers were synthesized via a two‐step process: (1) radical copolymerization of styrene with 1–4 mol% isopropenyl‐α, α‐dimethylbenzyl isocyanate (TMI) and (2) anionic ring‐opening polymerization of ε‐caprolactam using St/TMI copolymers (PST) as macroinitiators. The products comprised unconverted PST, PA6 homopolymer, and PS‐g‐PA6 (38.4%–42.0%), as quantified by selective solvent extraction. These ternary systems exhibited exceptional thermal stability (Td5 = 356°C–383°C) and served as effective compatibilizers for PA6/PPO and PA10T/PPO blends. The PA6/PPO blend compatibilized with 2% optimized PS‐g‐PA6 copolymer achieved tensile and flexural strengths of 56.5 and 113.3 MPa, respectively, representing enhancements of 43.9% and 36.3% over the uncompatibilized blend (39.3 and 83.1 MPa). Furthermore, these compatibilized blends also demonstrated high melt flow rate values (70.2–74.5 g/10 min), attributable to the absence of chain‐extension reactions between the compatibilizers and blend components. For PA10T/PPO systems, compatibilization increased tensile strength by 33.1% (from 52.2 to 69.5 MPa). The synthesized PS‐g‐PA6 comb‐type copolymers exhibit broad applicability in immiscible polymer blends, while the enhanced PA/PPO systems demonstrate strong commercial potential for automotive and electronic applications.