Study On Preparation And Properties Of The Strong Antibacterial PP/Nano-TiO₂/CCA Nanocomposites Material

It is a common problem in the study of polypropylene?PP?compound antibacterial materials that the antibacterial property is not strong enough.Therefore,it is of great significance to study how to make a strong antibacterial PP composite material with excellent comprehensive performance under low antimicrobial content.In this experiment,a novel Nano-TiO₂/CCA composite antibacterial agent?GNano-TiO₂/CCA?was produced by using the principle of photosynthesis of chlorophyll,combining chlorophyllin copper acid?CCA?with a coupling agent modified Nano-TiO₂.By CCA,the absorbed visible light energy can be converted into chemical energy to be transferred to Nano-TiO₂,improving the utilization of Nano-TiO₂ light energy,thereby improving the photocatalytic antibacterial efficiency of Nano-TiO₂.The PP/GNano-TiO₂/CCA composite antibacterial material was produced by blending composite antibacterial agent and PP with thermomechanical melt.Through the characterization of antibacterial,mechanical properties,MFR,rheological properties,DSC and TG of composite antibacterial materials,effects of the modification of Nano-TiO₂,unmodified Nano-TiO₂ and coupling agent modified,and Nano-TiO₂/CCA composites prepared by Nano-Ti O₂ and CCA and KH570modified Nano-TiO₂ on the overall performance of PP composites by different coupling agents was studied.By using Fourier Transform infrared spectroscopy?FTIR?analysis and water contact angle analysis?WCA?,the activation index and other characterizations,explored the effects of four coupling agents on the modification of Nano-Ti O₂.The main conclusions are as follows:?1?In the PP/GNano-TiO₂ composite produced by modifying Nano-TiO₂ with four different coupling agents:KH560,KH570,titanate coupling agent NDZ-105,and stearic acid.Among these four coupling agents,KH570 performs best in antibacterial performance,comprehensive mechanical properties and thermal properties of the composites.When the content of GNano-TiO₂ is 2%,the antibacterial rate of it reaches 90.6%,which has antibacterial effect,but does not achieve strong antibacterial effect;its tensile properties,fracture elongation,impact strength and flexural modulus were 29.7 MPa,612%,80.1kJ/m2,and 820MPa respectively.11.8%,33.0%,13.0%,and 27.7%higher than those before modification;the thermal decomposition initiation temperature was 426°C and 424°C.?2?Comparing the properties of PP/Nano-TiO₂ and PP/GNano-TiO₂ composite antibacterial materials obtained by using Nano-TiO₂ modified with Nano-TiO₂ and a silane coupling agent KH570 as antibacterial agents respectively,discovers that the content of Nano-TiO₂ ranging from 0 wt%to 2.0 wt%,with the increase of the amount of Nano-TiO₂ added,the antibacterial ratios of both antibacterial materials increased first and then decreased.When the content of Nano-TiO₂ was the same,the antibacterial performance,mechanical properties and thermal stability of PP/GNano-TiO₂ are obviously better than those of PP/Nano-TiO₂,and the rheological properties are basically unchanged.When the content of Nano-TiO₂ is 1.5wt%,The antibacterial rate of Nano-TiO₂ is preferably 73.2%,and it does not have antibacterial effect.When its content is 1.0 wt%,the antibacterial rate of PP/GNano-TiO₂ reaches91.3%,which has reach the antibacterial qualification,but it does not have a strong antibacterial effect.?3?The addition of CCA in the antibacterial agent Nano-TiO₂ increases the antibacterial rate,mechanical properties and melt flow rate of PP/GNano-TiO₂/CCA composites decrease slightly.When the content of Nano-TiO₂ is 1wt%and the mass ratio of Nano-TiO₂ to CCA is 6:1,the antibacterial rate of the composite is as high as99.9%,which has meet the strong antibacterial qualification.Its tensile strength and impact strength decreased by 5%and 10%.With the increase of the angular frequency,the PP/GNano-TiO₂/CCA composites show obvious shear thinning behavior.With the increase of the ratio of GNano-TiO₂ occupied by CCA,the storage modulus?G??loss modulus?G"?and complex viscosity??*?of the composite materials show a slight decrease,but the decrease is not obvious.With the increase of the proportion of Nano-TiO₂,the crystallization temperature of PP/GNano-TiO₂/CCA composites increases first and then decreases,but its melting temperature has little effect;the initial decomposition temperature and the maximum degradation rate all decrease to varying degrees,but the decrease was minimal and has little effect on the thermal stability of the composite material.