Preparation Of Self-crosslinking Fluorocarbon Acrylic Emulsion And Antibacteria Application

The fluorocarbon emulsion resin is widely used to many fields such as textile,building,leather, packaging due to it's outstanding stability and water repellency, oil repellency characteristics.In order to improve the mechanical behavior of emulsion resin,in this work,the room-temperature self-cross-linking fluorine-containing polyacrylate emulsion which has core-shell structure and antibacterial self-cross-linking emulsion fluorocarbon which has good antibacterial property were prepared by adding some moderate nano silver particles to fluorocarbon emulsion.Firstly, a series of fluorine-containing acrylate copolymer emulsion was synthesized by semi-continuous method using SDS and OP-10 as compound emulsifier, methl Methacrylate (MMA),butyl acrylate (BA) and dodecafluoroheptyl methacrylate (DFHM) as acrylate monomers.The production technology and process of emulsion polymerization was optimized,the optimal polymerization reacted condition based on SDS and OP-10 as emulsifier was that:the amount of the emulsifier was 1～2%,the radio of SDS/OP=1/2~1/3,the temperature at 80~85℃,the dosage of nitiator was 0.4~0.6%,stirring speed was 250~300 rpm.The monomer conversion was more than 98% an Gel conversion was less than 0.5%.Transmission electron microscopy(TEM) and laser scattering particle size analyze were used to analyze Latex particles,The results showed that fluorocarbon emulsion had a single dispersion,about 100-150 nm.Beside that,the latex films were also analyzed by Miriam Fourier transform infrared spectroscopy (FTIR),contact angle analyzer,water absorption and other methods.The results showed that contact angle increases and surface water absorption decreaseds as the amount of DFHM increasing.When the ammount of DFHM was 10%,the contact angle of latex film increases from 65°to 101.7°,water absorption deceases from 28% to 7.8%.Fluorine-containing polymer chains have the enriching tendency to the surface of latex film,the interface of air and film has a higher contact angle.Secondly,a series of room temperature self-cross-linking fluorocarbon emulsion were synthesized by adding diacetone acrylamide (DAAM) based on the synthesis of fluorocarbon emulsion above,The infrared spectra was used to analyze cross-linking reaction of ketones carbonyl and hydrazide,the results showed that the reaction of ketone carbonyl and hydrazide of the non-fluorocarbon emulsions was almost completely reacted at room temperature in 48h.But as for the fluorocarbon emulsion,the reaction was relatively slow,the carbonyl ketone disappeared in 72h.the before and after cross-linking performance of non-fluorocarbon emulsions and fluorocarbon emulsion were analyzed by water contact angle,water absorption and tensile strength and other methods,the results of contact angle showed that contact angle decreased as the mass fraction of DAAM increasing before cross-linking, however,the contact angle first increased and then decreased as the mass fraction of DAAM increasing after cross-linking,a maximum value appeared when the mass fraction of DAAM was 4%,and that the contact angle of non-fluorinated latex film lower than the fluorinated latex film, non-cross-linking of the latex films are lower than cross-linked by ADH under the same mass fraction of DAAM.When the mass fraction of DAAM from 0% to 8%,the contact angle of non-fluorinated latex films decreased from 62.9°to 44.3°,the fluorinated latex films decreased from 99.8°to 88.4°before cross-linking.non-fluorinated and fluorinated were in maximum value when DAAM=4%,the values were 80.6°and 96.8°respectively after cross-linking.The results of Water absorption showed that Water absorption increased as the mass fraction of DAAM increasing before cross-linking,but it first decreased and then increased as the mass fraction of DAAM increasing after cross-linking,the water absorption was in minimum value when DAAM=4%,Water absorption of non-fluorocarbon latex film was higher than fluorocarbon latex film, When the mass fraction of DAAM from 0% to 8%, the water absorption of non-fluorinated latex films decreased from 62.9°to 44.3°,fluorinated latex films decreased from 99.8°to 88.4°before cross-linking,the water absorption of non-fluorinated and fluorinated were in minimum value when DAAM =4%,the values were 13% and 6% respectively after cross-linking.The results of tensile strength showed that the tensile strength decreased as the mass fraction of DAAM increasing before cross-linking,but it increased by the mass fraction of DAAM increasing after cross-linking,However,the non-cross-linked fluorocarbon latex films before and after cross-linking rangeability of tensile strength was small than cross-linked fluorocarbon latex films. When the mass fraction of DAAM from 0% to 8%,the tensile strength of non-cross-linked fluorinated latex films increased from 7.5MPa to 32MPa,and the fluorinated latex films increased from 12.5MPa to 30MPa.Finally, the nano silver antibacterial latex was obtained by blending nano silver in the room temperature and self-cross-linking fluorocarbon emulsion which had been prepared.The antibacterial properties of the emulsion were studied, The results showed that nano silver and emulsion had good compatibility and excellent anti-bacterial,the antibacterial property of coating increased significantly as the amount of nano silver increasing,However,when the amount of nano silver reached 0.02%,the sterilization rate moderated when increasing the amount of nano silver,the sterilization rate reached 93.6% after 3 hours.