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When PPS was invaded by free radicals, Bis-mAO-SiO 2 , which was uniformly dispersed in PPS with high thermal stability and antioxidant efficiency, quickly provided a lively hydrogen atom to combine with the free radicals generated at the early stage of oxidation, blocking the oxidation process of PPS free radicals and inhibiting the oxidative degradation of PPS to the maximum extent. [Display omitted] • Bis-mAO-SiO 2 containing bis-hindered phenolic antioxidant was innovatively prepared. • PPS/Bis-mAO-SiO 2 composite was manufactured via melt processing. • Bis-mAO-SiO 2 effectively retarded the oxidative degradation of PPS. • Provides a good insight for the antioxidant modification of PPS and other materials. In recent years, loading antioxidants onto inorganic nanoparticles has attracted increasing interest. However, the existing studies not only have low antioxidant loading efficiency, but also ignore the relationship between structural changes and antioxidant properties before and after antioxidant modification, greatly limiting the improvement of the antioxidant properties of composites and their application scope. In this work, we successfully prepared bis-hindered phenolic antioxidants containing silica hydroxyl groups (Bis-mAO) and loaded them onto silicon dioxide (SiO 2) to get the nanocomposites (Bis-mAO-SiO 2). The melt blending method further prepared the corresponding polyphenylene sulfide (PPS)/Bis-mAO-SiO 2 composites. The results showed that the higher antioxidant loading and more suitable antioxidant structure made Bis-mAO-SiO 2 possess excellent antioxidant properties. The prepared PPS/Bis-mAO-SiO 2 composites remained stable under high temperatures and oxygen environments. Impressively, the maximum weight loss rate temperature of PPS/Bis-mAO-SiO 2 was increased by 11.60 °C compared to that of PPS, and after accelerated thermal oxidation at 220 °C for 24 h, the relative intensity ratio between O and C of PPS/Bis-mAO-SiO 2 only increased to 0.086, much lower than 0.132 for PPS. Moreover, the viscosity of PPS/Bis-mAO-SiO 2 only increased by 29.05 % and 88.75 % after accelerated thermal oxidation at 220 °C for 12, 24 h. Compared, PPS's viscosity increased substantially by 79.22 % and 250.3 %, respectively. This meant that the Bis-mAO-SiO 2 successfully achieved a synergistic integration of high antioxidant properties and thermal stability, implying that the work offered a strategy for fabricating high-temperature resistant antioxidant composites. [ABSTRACT FROM AUTHOR]

Polyphenylene sulfide (PPS), commonly used as a core material for high-temperature flue gas treatment, exhibits elevated viscosity when processed even at temperature exceeding 280 °C. In this study, a novel high-flowability PPS-based composite was fabricated through the incorporation of graphitic carbon nitride (g-C 3 N 4) via a well-established melt extrusion procedure. The enhancement of flowability in PPS was verified, and the material's texture structures and fundamental properties of composites with varying contents were determined. The composites exhibit well-dispersed g-C 3 N 4 , a significant reduction in shear viscosity (>10 %), a notable increase in melt index (>30 %), improved crystallinity, and comparable or superior performance compared to pure PPS. When the g-C 3 N 4 was introduced into the PPS matrix, a phase-separated composite structure was formed. This structure reduces the entanglement degree between the PPS molecular chains and provides more space for free-movement of the PPS chains, and thus the improvement in flowability for the composites can be clearly demonstrated. Therefore, g-C 3 N 4 can be used as a novel flow modifier to enhance the flowability and stability of PPS resin without compromising its fundamental properties, which offers significant prospects for improving productivity, optimizing energy usage, and managing costs for PPS-based products. [Display omitted] • PPS/g-C 3 N 4 composites was fabricated via a mature melt blending procedure. • g-C 3 N 4 could improve the flowability of PPS under high temperature processing. • π-π interaction improved the compatibility between PPS and g-C 3 N 4. • The composites achieved comparable or better properties under normal measurement. [ABSTRACT FROM AUTHOR]