Preparation Of High Antibacterial And Low Mobility Inorganic-Organic Composite Antibacterial Agent And Its Application In Polypropylene

Bacteria,fungi,and other microorganisms are the main causes of human infections such as skin inflammation,pneumonia,and meningitis.Antibacterial materials have become an inevitable demand for the development of human society.With the wide application of polymer materials,antibacterial polymer materials have become an important research direction.Polypropylene(PP)materials are widely used in medical equipment,daily chemical products,automotive parts,children's products,etc.Therefore,antibacterial polypropylene occupies a very important position in the field of antibacterial polymer materials.Due to the problems of low antibacterial efficiency and migration of single-component antibacterial agents,it is difficult to prepare antibacterial polypropylene with high antibacterial rate and low migration properties.Therefore,the research of composite antibacterial agents combining the advantages of low migration,heat resistance of inorganic antibacterial agents,and the safety,environmental protection,and high antibacterial properties of natural antibacterial agents among organic antibacterial agents has broad application prospects.In this paper,the inorganic antibacterial agent zinc oxide(ZnO),the natural antibacterial agents cinnamaldehyde(CA)and thymol(THY)were combined to preparation three inorganic-organic composite antibacterial agents with high antibacterial rate and low mobility.We studied the antibacterial properties,surface hydrophobicity,and mechanical properties of antibacterial PP composites.First,in this paper,the inorganic-organic antibacterial agent O-ZnO-CA was prepared by grafting a natural antibacterial agent CA on the surface of an inorganic antibacterial agent nano-zinc oxide(O-ZnO)modified by coupling agent ?-aminopropyltriethoxysilane(KH550),and melt blended it with PP to prepare PP/O-ZnO-CA composites.The antibacterial and mechanical properties of PP/O-ZnO-CA composites and the mobility of O-ZnO-CA in PP matrix were studied.The results showed that when the addition amount of O-ZnO-CA was only 4 phr,the antibacterial rates of PP/O-ZnO-CA composites against E.coli and S.aureus were 75.6% and 70.9%,which was increased by 12.4% and 13.6% compared with PP/O-ZnO composites.What's more,O-ZnO-CA has no migration in PP matrix.Secondly,in order to further improve the antibacterial performance of antibacterial PP composites,a natural antibacterial agent thymol(THY)with better antibacterial performance than CA was grafted on the surface of O-ZnO to prepare an inorganic-organic composite antibacterial agent O-ZnO-THY.The antibacterial and mechanical properties of PP/O-ZnO-THY composites and the migration properties of O-ZnO-THY in PP matrix were studied.The results show that when the amount is 4 phr,the antibacterial rate of PP/O-ZnO-THY composites against E.coli and S.aureus reaches 93.2% and 72.1%.It was increased by 17.6% and 1.2% compared with PP/O-ZnO-CA.This is because THY has a hydrophilic phenolic hydroxyl group,which is more likely to have an antibacterial effect on the more hydrophilic E.coli.Similarly,O-ZnO-THY has almost no migration in the PP matrix.Finally,due to the synergistic antibacterial effect between CA and THY,this article further grafted CA and THY to the surface of O-ZnO,prepared an inorganic-organic composite antibacterial agent O-ZnO-CT,and the same ratio of O-ZnO-CA and O-ZnO-THY antibacterial agent was used as a reference.The antibacterial properties of PP/O-ZnO-CT and PP/O-ZnO-CA/ O-ZnO-THY composite materials and the migration properties of two composite antibacterial agents in PP matrix were studied.The results showed that when the amount was 4 phr,the antibacterial rate of PP/O-ZnO-CT composites against E.coli and Staphylococcus aureus reached 95% and 90%.Compared with PP/O-ZnO-CA composites,it has increased by 20% and 21%,compared with PP/O-ZnO-THY composite materials,it has increased by 2% and 20%,and compared with PP/O-ZnO-CA/O-ZnO-THY composite materials,it has increased by 5% and 10%.This is because when CA and THY are connected to the surface of O-ZnO at the same time,CA and THY are prone to produce antibacterial synergy.Migration tests also showed that O-ZnO-CT did not migrate in the PP matrix.