High-impact marine antifouling HDPE composites based on synergistic covalent and ionic bonding with poly (hexamethylene guanidine)

The high-density polyethylene (HDPE)/ethylene–acrylic acid block copolymer (EAA)/poly (hexamethylene guanidine) (PHMG) composites with outstanding comprehensive properties were successfully fabricated through the synergistic design of covalent and ionic bonds with PHMG. Structural characterization confirmed the formation of amide bonds, while rheological and thermal analyses jointly demonstrated that the covalent bonded PHMG significantly enhanced molecular chain entanglement. This entanglement effect led to synergistic optimization of both tensile strength and toughness in this composite. Compared to pure HDPE, the HDPE/EAA/PHMG composites showed a slight decrease in tensile strength but a substantial 302 % surge in impact strength. Ionic bond modification of the composite material via PHMG solution immerse effectively enhanced its antibacterial properties, demonstrating good inhibitory effects against both E. coli and S. aureus . Furthermore, the modified material exhibits outstanding antifouling performance, reducing Chlorella attachment by 91.6 %. A three-month in marine test further validated its effective inhibition of algal growth. This research offers innovative material design concepts and technical pathways for developing high-performance marine antifouling materials that integrate significantly boosted toughness with outstanding antifouling performance.