Plasma‐Modified Graphene Nanoplatelets for Reinforcement of Polypropylene Nanocomposites

ABSTRACT Achieving uniform dispersion and strong interfacial interaction between graphene nanoplatelets and polymer matrices remains a critical challenge in the development of high‐performance polymer nanocomposites. In this work, graphene nanoplatelets (GNPs) were mechanically pretreated by ultrasound and subsequently surface‐modified by plasma polymerization to improve their compatibility with a polypropylene (PP) matrix. Surface modification was performed in a rotary plasma reactor using propylene monomer (C ₃ H ₆ ) excited by two different energy sources: radiofrequency (RF, 13.56 MHz) and high‐voltage (HV) discharge. The modified GNPs were incorporated into PP, and the resulting nanocomposites were characterized by solvent dispersion tests, X‐ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and tensile testing. The results show that plasma surface modification improves nanoparticle dispersion and enhances interfacial interactions with the polymer matrix. The incorporation of GNPs increased the thermal stability of the nanocomposites by up to 65°C relative to pristine PP and produced an increase in Young's modulus of approximately 50%. Under the experimental conditions employed, nanocomposites prepared with HV‐modified GNPs exhibited improved dispersion behavior and enhanced mechanical performance. These findings demonstrate that plasma‐assisted surface modification is an effective strategy for improving the performance of polypropylene‐based nanocomposites reinforced with graphene nanoplatelets.