Surface modification of polypropylene with poly(3-hexylthiophene) via oxidative polymerization

Poly(3-hexylthiophene)-graft-polypropylene (P3HT-g-PP) was successfully prepared through a two-step reaction by incorporating poly(3-hexylthiophene) (P3HT) onto the surface of polypropylene (PP). PP was first functionalized with styrene, yielding polystyrene-graft-polypropylene (PS-g-PP) and 3HT was subsequently polymerized on PS-g-PP via FeCl3 oxidative polymerization. Crosslinking between the 3HT unit and aromatic ring of styrene attached to the surface of PP improved the thermal stability and conductivity of PP. The absorption and emission peaks of P3HT-g-PP in the range of 500-600 nm provided evidence of pi-pi(star) conjugation in the 3HT unit grafted to PP. The presence of the P3HT layer on the surface of PP also changed the crystal structure of PP. The presence of sulfur originating from P3HT was confirmed by elemental mapping using transmission electron microscopy energy dispersive X-ray (TEM-EDX) analysis.