The present study attempted to prepare para phenylene diamine functionalized multiwalled carbon nanotube (f-MWCNT) incopoarated polymer of a new pyrene core containing cardanol based benzoxazine (PyCBz) composite (f-MWCNT-PPyCBz). For this, a new monomer of pyrene core containing cardanol based benzoxazine (PyCBz) was synthesized through solventless method and its structure was confirmed using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance spectroscopy (H-1 & C-13) and MALDI mass. In addition, multiwalled carbon nanotube (MWCNT) was functionalized using para phenylene diamine that acted as effective filler for preparation the composite materials. The curing behavior and thermal stability of para phenylene diamine functionalised multiwalled carbon nanotube (MWCNT) incopoarated pyrene core containing cardanol based polybenzoxazine(PPyCBz) composites were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Antimicrobial studies were also carried out using Streptococcus pyogens, Bacillus cereus, Staphylococcus aureus and Escherichia coli. In short, the obtained f-MWCNT/PPyCBz nanocomposites possess high dielectric constant, good antibacterial and photo luminescent properties, which may find optical, antimicrobial and high dielectric applications. (C) 2016 Elsevier Ltd. All rights reserved.