Surface modification of polypropylene with poly(methyl methacrylate) initiated by a diethylzinc and 1,10-phenanthroline complex

Methyl methacrylate (MMA) was grafted onto the surface of polypropylene (PP) films and fibers through simple radical polymerization of diethyl(1,10-phenanthroline N1,N10)zinc (Phen-DEZ) and with oxygen molecules as the radical initiator. The grafting yield could be changed by varying the reaction time, temperature, and amount of solvent. The resultant grafted PP films were characterized by Fourier transform infrared spectra, Raman spectra, and X-ray diffraction measurements, as well as thermogravimetric analysis. The surface morphology of the grafted PP film was analyzed using an atomic force microscope. Furthermore, the usual hydrophobic surface behavior of PP film became hydrophilic, as observed from the change in the water contact angle (106.1° to 64.8°), after grafting with PMMA. The scanning electron microscopy images showed that the graft polymerization process did not change the original microstructure of PP fibers. From the results of these analyses, it was proved that MMA could be grafted to the PP films using the novel Phen-DEZ/O2 initiator.