Preparation Of UV Curable Nano-silver Antibacterial Masks

In recent years,China's economy has developed vigorously,but behind the strong development,more and more negative problems have attracted people's attention,especially air pollution.People are gradually aware of the harmfulness of air pollution to health.Relevant departments actively formulate policies to improve the environment,but the effect of treatment is slow.Especially when the concept of PM2.5 was introduced,people were panicked about environmental pollution.In order to reduce the harm of environmental pollutants to their families and themselves,masks,as simple protective devices,became indispensable consumables in life.A variety of protective masks appeared on the market,mainly to block and filter particulate matter.In order to filter particulate matter and eliminate bacteria,a new type of antimicrobial finishing agent was used to prepare disposable antimicrobial masks with good performance and low cost.In this study,silver nanoparticles were synthesized from polyvinylpyrrolidone,silver nitrate and ethylene glycol.The silver nanoparticles were characterized by transmission electron microscopy,ultraviolet absorption spectrometry and agar plate diffusion method.The size of the silver nanoparticles was about 20 nm.The silver nanoparticles were spherical and uniformly dispersed without agglomeration,and had good antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae.The waterborne polyurethane emulsion was synthesized from pentaerythritol three acrylate(PETA),three ethylamine(TEA),two butyltin two,laurate(DBTDL)and ethylenediamine(EDA).The stability,particle size and solid content of the emulsion were determined.It was proved that the particle size was about 100 nm,the solid content was controlled between 35%~39%,and the stability was good,and the chamber temperature could be kept for 6months or more.Waterborne polyurethane film was prepared by UV curing technology with high efficiency,energy saving and environmental protection.The structure and composition of UV curing film were analyzed by FT-IR Fourier transform infrared spectroscopy.The optimum UV curing time was 15 s.The mechanical properties of different UV cured films were tested.The elongation at break was about 250%.The fracture stress and strength increased with the increase of the molar ratio of NCO:OH.The water absorption test of different UV curingmembranes shows that the water absorbency is not very different.Finally,the waterborne polyurethane emulsion with R value of 1.6,1.8 and 2 is selected for the next non-woven fabric antibacterial finishing experiment.The optimum finishing conditions were determined by inquiring into the optimum finishing process.Antibacterial nonwovens were obtained by using two-dipping and tworolling method with bath ratio of 1:80,rolling liquid ratio of 100%,pre-baking at 50 for 4 min,baking at 120 for 3 min,and then adding 4% photoinitiator to the finished samples for UV curing.Nano silver / waterborne polyurethane composite emulsion with concentration of 50 g/L,100 g/L and 150 g/L was prepared,and the content of silver nanoparticles was controlled at 1%.2%,3%,4%,antibacterial non-woven fabric samples were prepared by two dipping and two rolling methods.The samples were cured by UV after baking and drying,and then tested by AATCC 100 antimicrobial standard.The results showed that: 1.6-50 g/L,4% nano-silver,1.6-100g/L,3% nano-silver,1.8-150 g/L and 4% nano-silver.The three gradients had the highest bacteriostasis rate and could be used for subsequent mask preparation.After testing the properties of non-woven fabric before and after anti-bacterial finishing,it was found that UV curing made anti-bacterial finishing agent finish on non-woven fabric;UV curing anti-bacterial finishing agent improved the thermal stability of non-woven fabric;after finishing,the whiteness of non-woven fabric decreased,and the whiteness of waterborne polyurethane decreased with the increase of the concentration of waterborne polyurethane;after finishing,the degree of wrinkle recovery angle has been improved,which indicates that the wrinkle resistance of non-woven fabrics has been improved;the breaking strength of non-woven fabrics after finishing has increased slightly,but the elongation has decreased significantly;after finishing,the contact angle of non-woven fabrics has reached more than 100 degrees,and the anti-bacterial finishing has endowed non-woven fabrics with better hydrophobicity;at the same time,the moisture permeability of non-woven fabrics has been slightly improved,and the water-based polyuret Esters have no effect on moisture permeability.