Synthesis and characterization of new graft copolymers based on ozonized polyethylene: Comparative approach between mass and solution grafting

Abstract

New graft copolymers were developed from low-density polyethylene (LDPE) and high-density polyethylene (HDPE) following an initial ozonation step to introduce reactive functional groups onto the polymer backbone. Among the two polymers, LDPE demonstrated superior susceptibility to ozonation, making it the preferred substrate for subsequent grafting. Grafting was then performed primarily on ozonized LDPE using various functional monomers, including acrylic acid (AA), 4-vinylpyridine (4VP), acrylonitrile (AN), chloromethylstyrene (CMS), as well as copolymers such as AA–vinylphosphonic acid (AA-co-VPA) and AN–vinylphosphonic acid (AN-co-VPA). Grafting was carried out using both solution and melt techniques. The resulting materials were characterized by elemental analysis and Fourier transform infrared (FT-IR) spectroscopy, confirming the incorporation of heteroatoms and the presence of characteristic functional groups. Grafting performed in solution consistently yielded higher efficiencies compared to melt grafting, likely due to improved monomer diffusion and enhanced reactivity of active sites. These graft copolymers exhibit significantly enhanced surface hydrophilicity due to the increased surface polarity and functional group diversity, positioning them as promising candidates for applications in water purification membranes, ion exchange resins, sensors, biomedical devices, and composite materials requiring enhanced interfacial interactions.