Study On Performances And Application Of Acrylate Polymer Composite Emulsion Modified By Fluorine And Nano-TiO₂

Acrylate polymers play a very important role in the field of coatings and composites.However,due to their poor heat resistance,aging resistance and mechanical properties,their waterproof and antifouling properties are not ideal,so it is necessary to be modified to improve the performance.Fluorinated polymers have excellent heat resistance,aging resistance,chemical stability resistance,self-cleaning performance and very low surface energy.Meanwhile Nano-TiO-has high catalytic activity,strong oxidation ability,good antibacterial and self-cleaning performance,and can also improve the physical and mechanical properties of polymer materials.Therefore,fluorinated monomer and nano TiO2 are introduced into acrylate polymers,and fluorine-containing acrylate nanocomposite emulsion with excellent water repellency,oil repellency,antibacterial property,heat resistance,aging resistance and mechanical properties can be prepared.In this study,methyl methacrylate(MMA),sodium vinyl sulfonate(ES),butyl acrylate(BA)and perfluorooctyl ethyl acrylate(FM)were used as main monomers to form prepolymer in the presence of oil initiator.And then Ti3OT was used as the precursor of nano-TiO2,KH570 was used to modify the hydrolysate,the resulting modified nano-TiO2 reacted with the prepolymer under the action of waterborne initiator potassium persulfate(KPS),then the high performance anionic acrylate polymer modified by fluorine and nano-TiO2 composite emulsion was prepared.Studied the effects of synthesis conditions on the properties of polyacrylate emulsion and latex film,tested the properties of the composite emulsion and latex film and applied the composite emulsion to paper and fabric,studied the properties of paper and fabric treated by composite emulsion.The main contents of this paper are as follows:Firstly,the synthesis conditions of acrylate polymer modified by fluorine and nano-TiO2 were studied.The optimum synthesis conditions were as follows:m(FM):m(ES):m(TBOT):m(KH570)=6:4:2:3,the ratio of soft and hard monomer BA:MMA was 1:1,pH value was 8,KPS dosage was 0.5%,reaction temperature was 80?,reaction time was 5 hours.Under these conditions,the emulsion is stable and the water repellency of the latex film is good.The hardness of the composite latex film is between H-2H,and the impact strength is 42 kg.cm.Then the structure and properties of the acrylate polymer modified by fluorine and Nano-TiO2 were characterized.Infrared spectrum(FT-IR),1H-NMR,X-ray photoelectron spectroscopy(XPS)and UV result indicated FM and Nano-TiO2 modified by KH570 has been grafted into the polymer.transmission electron microscopy(TEM)and laser particle size analyzer(DLS)showed that the latex particles were spherical and distributed uniformly,with a diameter of 150-200 nm and a narrow particle size distribution,the emulsion was stable.Electron microscopy(SEM),atomic force microscopy(AFM),contact angle measuring instrument(CA)and thermogravimetric analyzer(TG)analysis showed that compared with pure polyacrylate,the surface of the film was obviously rough,with micro grooves and gullies,and the water and oil repellence of the film was significantly improved,the contact angle of the composite latex film for water and two iodine methane reached 120° and 113° degrees respectively.The addition of fluorine and nano TiO2 increased the thermal decomposition temperature of the composite latex film,enhanced the thermal stability of the copolymer,and reduced the surface tension of the emulsion.The composite emulsion was used as the surface sizing agent.The optimum technology was the amount of the composite emulsion was 1%,the temperature was 120? and the treatment time was 3 min.At this time,the paper had the best water and oil repellence,and the contact angle for water and CH2I2 could reach 138.40 and 124.70 respectively.After sizing the fiber was closely arranged,the surface of the paper was tight and smooth,and the free energy on the surface was reduced to 5.03 mJ/m2.The paper's tensile strength,folding and sliding were all improved.XPS analysis of paper fiber showed that there are F and Ti elements after sizing.The results of antibacterial activity showed that the width of bacteriostatic ring increases with the increase of nano-TiO2.When nano-TiO2 is 10%,the average width of bacteriostatic ring is 2.04 mm.The composite emulsion was used as fabric finishing.after finishing,the fabric surface fold desalination,water and oil repellence properties are improved,the waterproof grade is 90 points,the oil resistance level reaches 6,and the surface free energy is reduced to 4.39 mJ/m2.The whiteness,softness and air permeability of the fabric show that each index has a slight decrease,but there is not much influence.XPS analysis showed that there were F and Ti elements in different surface interfaces of the finished fabric.antibacterial analysis showed that the antibacterial property of the finished fabric increased with the increase of nano-TiO2 concentration.