Hemp is a good option for polyethylene additives because of its high cellulose and fibrous content. This study aims to modify natural hemp fibers with the maleic anhydride/ionic liquid method, manufacture the composites, and compare the thermal and mechanical properties of natural hemp fiber and hemp cellulose. In this study recycled polyethylene as a binder, and filling ratios between 0 and 50 (wt/wt)% are investigated as a parameter. Differential scanning calorimeter and thermomechanical analysis were performed, and it was determined that the coefficient of thermal expansion from 973 to 147 ppm/K. It was determined that the strength of composite materials obtained from cellulose fibers with maleic anhydride/liquid ionic modification improved by around 20% from 19.5 to 24.4 MPa. In addition, as a result of scanning electron microscope analyses performed on the fractured surfaces, it was determined that the pressure, temperature, and time were suitable for producing composite materials. This work shows the potential of recycled polyethylene/hemp composites as a sustainable green material with simple fabrication procedure and useful mechanical and thermal properties.

Conductive composite nanofibers are promising materials, especially wearable strain sensors, due to their lightweight, breathability, flexibility, and skin affinity. Here, we propose a dual‐conductive network by the sequential decoration of amin‐modified boron nitride nanosheets (BN), copper nanoparticles (Cu), and polyaniline (PANI) into the elastic thermoplastic polyacrylonitrile (PAN) nanofiber. The Cu nanoparticles/BN‐enwrapped PANI nanocomposite was synthesized using successive environmentally friendly reduction and chemical oxidation polymerization. First, Cu (II) ions were immobilized on modified BN and reduced with L‐ascorbic acid (BN@Cu), followed by a chemical oxidation polymerization of aniline using ammonium persulfate as an initiator (BN@Cu/PANI). The XRD (X‐ray diffraction), FTIR (Fourier Transform Infrared Spectroscopy), SEM (Scanning Electron Microscopy), and TEM/EDXS (Transmission Electron Microscopy/Energy Dispersive X‐ray Spectroscopy) analysis confirmed the coexistence of the BN@Cu/PANI phase and composition. The DC electrical conductivity of BN@Cu/PANI nanocomposite (0.567 S/cm) was quietly higher than PANI (0.167 S/cm) and BN@Cu (0.077 S/cm). The thermal conductivity of BN@Cu and BN@Cu/PANI was 0.626 and 0.444 W/mK, respectively. The BN@Cu/PANI loaded‐PAN composite nanofibers were successfully produced by electrospinning. SEM studies confirmed that the composite nanofibers have uniform fiber structure and suitable BN@Cu/PANI dispersion/distribution within the PAN. BN@Cu/PANI‐reinforced PAN nanofibers showed a 2‐fold decrease in the specific heat capacity and a 50‐fold increase in electrical conductivity of the nanofibers at 10 wt%BN@Cu/PANI loading. This work offers dual‐conductive polymer‐based composites, which can be used in thermal management applications in microelectronics devices.Highlights: The dual‐conductive nanocomposite, BN@Cu/PANI, was prepared a simple, low‐cost method. BN@Cu/PANI, core/shell nanocomposite, was easily produced this way for the first time. BN@Cu nanoparticles increased the polymerization rate of PANI. The thermal and electrical conductivity of BN@Cu/PANI was 0.444 W/mK and 0.567 S/cm. Electrical conductivity of BN@Cu/PANI‐PAN increased 50‐fold increase at 10 wt%BN@Cu/PANI.