Study On Preparation Of Metal Oxide/chitosan @ Polypropylene Composite Melt-blown Material And Its Antibacterial And UV Resistance Properties

Polypropylene（PP）melt-blown nonwoven material with good mechanical properties and corrosion resistance has been widely used in medical and health fields.However,it is the fact that PP does not have antibacterial property and is easy to be oxidized and degraded under light,which affects its service life.Thus,these deficiencies limit the application of PP to some extent.Chitosan（CS）is a kind of natural alkaline polysaccharide,and has good biocompatibility,film forming and antibacterial properties.However,single-component CS coating lacks broad-spectrum antibacterial property and has poor long-term performance.In addition,zinc oxide（Zn O）and cuprous oxide（Cu₂O）are often used as antibacterial agents because of their high efficiency,broad-spectrum antibacterial activity and UV resistance properties.Therefore,CS may combine with Zn O or Cu₂O to achieve the purpose of synergistic antibacterial effect.In this paper,PP melt-blown material is functionally modified by use of CS combined with Zn O or Cu₂O to develop the PP composite melt-blown material with both antibacterial and UV resistance.It is hoped that the application field of PP melt-blown material is expanded.First,PP melt-blown material was modified by use of polydopamine（PDA）and polyethylenimide（PEI）to improve its surface hydrophilic and marked by M-PP.Through testing and analyzing the PP melt-blown material before and after the modification,the results showed that the M-PP surface was smooth,and appeared some polar groups.The water contact angle of M-PP decreased.These phenomena indicated that the hydrophilicity of PP melt-blown material significantly enhanced.Compared with the original PP melt-blown material,the fracture strength and elongation at break of M-PP melt-blown material slightly decreased Then,CS with different mass fractions was loaded on the surface of M-PP by impregnation method to obtain CS@M-PP melt-blown material.The results showed that CS could form uniform and dense membrane on the surface of M-PP.With the increase of CS mass fraction,the water contact angle of CS@M-PP melt-blown material increased and the hydrophilicity decreased.Compared with pure PP melt-blown material,when the mass fraction of CS was 1%,The fracture strength of the CS@M-PP melt-blown material increased from 0.32 MPa to 0.59 MPa,while the elongation at break decreased.It was believed that when the mass fraction of CS was 1%,the comprehensive performance of CS@M-PP melt-blown material was the best.Then,nano Zn O particles were prepared by sol-gel method.Through the characterization of morphology and structure,the results showed that the synthesized nano Zn O particles had a fusiform morphology.The length was about 200～600 nm,and the section diameter was about 100～300 nm.Zn O with different concentrations was loaded on the surface of CS@M-PP melt-blown material by ultrasonic method to obtain Zn O/CS@M-PP composite melt-blown material.It was found that Zn O could be evenly distributed on the surface of CS@M-PP.With the increase of Zn O mass concentration,the antibacterial efficiencies of Zn O/CS@M-PP composite melt-blown material against Staphylococcus aureus and Escherichia coli increased,and the UV protection factor（UPF）value also increased.When the Zn O concentration was 2mg/m L,the antibacterial efficiencies of Zn O/CS@M-PP melt-blown material against both Staphylococcus aureus and Escherichia coli could reach 99.99%,and the UPF value was 139.97.Compared with the original PP,the fracture strength of the CS@M-PP melt-blown material increased from 0.32 MPa to 0.82 MPa,and the longitudinal fracture strength decreased.Finally,Cu₂O particles were synthesized by glucose reduction method.The surface morphology and crystal structure of Cu₂O particles were characterized.The results showed that the prepared Cu₂O particles had an octahedral shape with a particle size of about 1μm.Then,Cu₂O was loaded on the surface of CS@M-PP by ultrasonic method to prepare Cu₂O/CS@M-PP composite melt-blown material.By testing and analysis,the results showed that Cu₂O could be uniformly loaded on the surface of CS@M-PP.Compared with the original PP melt-blown material,the thermal stability and hydrophilicity of Cu₂O/CS@M-PP composite melt-blown material had improved.When the mass concentration of Cu₂O was 2 mg/m L,the antibacterial efficiencies of Cu₂O/CS@M-PP composite melt-blown material against both Staphylococcus aureus and Escherichia coli could reach 99.99%,which presents the excellent antibacterial performance.The UPF value of Cu₂O/CS@M-PP composite melt-blown material was nearly 167.80,and the transmittance of UVA and UVB was only 0.99%and 0.46%,respectively,meaning the excellent UV resistance.With the increase of Cu₂O mass concentration,the fracture strength of Cu₂O/CS@M-PP composite melt-blown material increased first and then decreased,while the elongation at break decreased.In conclusion,when the loaded concentrations of both Zn O and Cu₂O were 2 mg/m L,the antibacterial efficiencies of Zn O/CS@M-PP and Cu₂O/CS@M-PP composite melt-blown materials against Staphylococcus aureus and Escherichia coli could reach 99.99%,showing the excellent antibacterial property.However,the UPF value of Cu₂O/CS@M-PP composite melt-blown materials is higher and the UV transmittance is lower.Therefore,compared with Zn O/CS@M-PP composite melt-blown material,Cu₂O/CS@M-PP composite melt-blown material had better the antibacterial and anti-ultraviolet comprehensive performances.