Preparation And Application Of Fluorine-containing Adhesive Bonding PTFE And Metal

In the automotive, textile, aerospace and other fields,polytetrafluoroethylene (PTFE)is highly valued due to its good resistance to the chemical corrosion, its hightemperature resistance and the extraordinary self-lubrication. However, it still has somedefects such as the poor mechanical performance, the large linear expansion coefficient,low surface energy and difficult adhesive. The thesis studies the good adhesionproperties of fluorine-containing adhesive for PTFE/metals.The thesis chooses sodium-naphthalene solution to modify the PTFE sheet surface,studies the influence of sodium-naphthalene solution concentration and processing timeupon PTFE surface structure, elements proportion as well as upon the water contactAngle. The experiment result shows the PTFE surface which is dealt bysodium-naphthalene solution becomes rough or partially damaged, and the ratio ofCarbon element and Fluorine element is turned to43:57from29:71; while dealt insodium-naphthalene solution of concentration0.6mol/L for15minutes, it will get abetter effect of modified performance, and the water contact angle of PTFE surface isreduced to59.4°from112.9°.The thesis chooses Polyvinylidene fluoride, Poly (vinylidenefluoride-co-tetrafluoroethylene-co-hexafluoropropylene), and Poly (vinylidene fluoride-co-hexafluoropropylene) as the adhesive of the basic material manufacturing, studiesthe adhesive effects of adhesive manufacturing with the types of basic materials, KOHsolution concentration, processing time,graft way and the amount of maleic anhydride.The infrared spectroscopy results shows that C=C is introduced in the main chainsince the basic material dehydrofluorinating after alkali treatment. Acid anhydridegroups were introduced to the substrate modified by grafting with maleic anhydridemonomer,three different adhesives were synthesized.The bonding effect show that withpoly (vinylidene fluoride-co-hexafluoropropylene) as the basic material,2,5-dimethyl-2,5-di (t-butylperoxy)hexane (pair25) and three of triallyl isocyanurate(TAIC) as a curing system, when the ratio of the curing agent dosage and glue dosagequality reaches5.5:100, the adhesive bonds and goes through175high temperaturecuring for90minutes, the bonding performance is ideal.The tensile shear strengthreaches1.7MPa (PTFE film rupture),and peel strength reaches4.72kN/m, meet therequirements of forming.