Boron nitride and few layers graphene incorporated carboxylated butadiene nitrile rubber hybrid nanocomposites: Preparation, properties and mechanistic insights

Abstract Herein, we report a scalable method for preparing stable aqueous dispersions of hexagonal boron nitride (h‐BN), suitable for incorporation into carboxylated nitrile butadiene rubber (XNBR) latex to produce high‐quality nanocomposites. Mono and hybrid nanocomposites of h‐BN/Few‐Layer Graphene (FLG) with XNBR were synthesized using probe sonication (PS) and high‐pressure homogenization (HPH). UTM analysis revealed significant improvements (7 to 10.9 and 12.4 MPa) in tensile strength (TS) for both mono (1.5 phr) and hybrid (FLG/h‐BN; 1.5/1 phr) nanocomposites prepared via HPH. The incorporation of exfoliated h‐BN and FLG into XNBR enhances thermal stability, restricts molecular chain mobility, and shifts the glass transition temperature (T_g) toward higher values (−26.7 to −21.6 °C) due to strong interfacial interactions, as confirmed by DMA and DSC analyses. Density functional theory (DFT) study highlighted preferential interactions between h‐BN and acrylic acid/butadiene units of XNBR over acrylonitrile. Antibacterial assays demonstrated synergistic increased inhibition zones (26 to 40 mm) to hybrid fillers (h‐BN ≥3 phr, FLG 1.5 phr) incorporated XNBR thin film nanocomposites against Pseudomonas aeruginosa. Toxicity studies on mouse fibroblast cell lines showed enhanced biocompatibility XNBR with h‐BN (>3 phr h‐BN incorporation with XNBR show >90% cell viability while raw XNBR demonstrates~65% toxicity). However, the hybrid fillers incorporation up to 1.5 phr of h‐BN show a maximum biocompatibility (>75% cell viability) compared to the parent material. The novel incorporation of h‐BN and FLG into XNBR provides strong evidence of the enhanced antibacterial efficacy and biocompatibility of the hybrid nanocomposites, underscoring their potential relevance in biomedical applications. Highlights The aqueous dispersion of h‐BN was prepared and characterized. Mono and hybrid nanocomposites of h‐BN with XNBR were synthesized using probe sonication (PS) and high‐pressure homogenization (HPH). Synergistic improvement in antibacterial and biocompatibility were observed.