Study And Preparation Of Medium Temperature Reversible Thermochromic Fluorocarbon Coatings

As a functional coating material,reversible discoloration coating is widely used in the fields of temperature indication material,equipment temperature safety warning,aerospace and so on.This material can be coated on metal,ceramic,glass and other substrates to form protective,decorative and functional coatings.However,most of the traditional discoloration coatings are solvent-based discoloration coatings,organic solvents are volatile,resulting in air pollution,and the discoloration materials are greatly affected by environmental factors.This paper adds the reversible discoloration materials microencapsulation to Water-in-oil polymer emulsion to synthesize environment-friendly reversible discoloration fluorocarbon coatings.In this paper,a semi-transparent pan-blue-light fluorinated polymer microemulsion was prepared by semi-continuous seed emulsion polymerization with trifluoroethyl methacrylate,butyl acrylate and methyl methacrylate.The effect of initiator,emulsifier and reaction temperature on emulsion synthesis was studied.By comparing the centrifugal stability and coating properties of fluorinated polymer microemulsion with pure acrylic emulsion,the results show that fluorinated polymer microemulsion and coating film have good centrifugal stability,high temperature resistance and self-cleaning properties.followed by Ag NO₃?Cu SO₄?KI reversible discoloration material was prepared in a certain proportion;Melamine Formaldehyde and Urea was used as wall material and reversible discoloration material as core material,and in situ polymerization was carried out under alkaline conditions to form reversible color microcapsules.Energy dispersive spectrum analysis and X ray diffraction analysis showed that the structure formula of reversible discoloration material is Cu Ag I₂;Scanning electron microscope characterization and temperature lifting test showed that the color change of reversible color microcapsules is obvious,the reversible effect is good,and the particle size distribution is between 0.7?2.5?m.Finally,the coating filler and additive pair were studied with fluoropolymer microemulsion as coating material and medium temperature reversible color microcapsule as coating pigment.Aluminium silicate were determined as the best coating filler by film reflectivity.the coating film has good temperature resistance,self-cleaning performance,coating adhesion of grade 2,the film hardness is 2 H,the film flexibility is 3 mm,the film normal temperature color is light blue,the high temperature color turns into light orange,cooling color occurs reversible discoloration to light blue,discoloration temperature is between 250?260?,discoloration time is about 50 s,polychromatic temperature is about 250?,polychromatic time is about 1 min,discoloration,polychromatic effect is obvious,repeatability is good,accord with product technical index requirement.