Hybrid Thin‐Film Nanocomposites of Natural Rubber With Hexagonal Boron Nitride and Few‐Layer Graphene: Improved Mechanical, Thermal and Antibacterial Properties

ABSTRACT Natural rubber (NR) nanocomposites reinforced with few‐layer graphene (FLG), hexagonal boron nitride (h‐BN), and their hybrid (h‐BN/FLG) were prepared to enhance mechanical, thermal, and antimicrobial properties. SEM and TEM analyses showed uniform dispersion of nanofillers in NR matrices at optimized loadings [NR‐FLG (1.5 phr), NR‐BN (1 phr), and h‐BN/FLG (1/1.5 phr)]. FT‐IR analysis confirmed the physicochemical interactions of NR with h‐BN, FLG, and their hybrid fillers. A new peak at ~1080 cm −1 appeared in NR/h‐BN and NR hybrid composites due to CB stretching, while a peak around 1540 cm −1 was observed in all the composites, indicating SS or sulfur‐related linkages between NR and the fillers. Tensile strength increased from 24.1 MPa (NR) to 31.1 MPa (NR‐FLG), 31.3 MPa (NR‐BN), and peaked at 35.1 MPa for the hybrid. Thermal stability also improved, with the initial degradation temperature ( T 10 ) rising from 325°C (NR) to 331°C (NR‐FLG), 341°C (NR‐BN), and 359°C (NR‐h‐BN/FLG). Differential scanning calorimetry (DSC) analysis of these nanocomposites showed a substantial reduction in Δ C p , indicating restricted chain mobility due to strong filler‐matrix interactions. Antibacterial studies against P seudomonas aeruginosa and S taphylococcus aureus revealed significantly increased inhibition zones (18–41 mm), enhanced biofilm inhibition (30%–55%), and ~100% contact killing efficiency. The mono and hybrid nanocomposites also exhibited superior biocompatibility in L929 cell lines. Overall, the incorporation of FLG and h‐BN into the NR matrix significantly improves its mechanical, thermal, and antibacterial properties, making it a promising candidate for biomedical applications such as finger cots, catheters, condoms, and gloves.