Study On Preparation And Properties Of Organic Fluorine And Crosslinked Double Modified Waterborne Polyurethane

Waterborne polyurethane?WPU?could be used with water replacing organic solvent,which could reduce environmental pollution due to use of organic solvent,so,it has attracted extensive concerns as a new-type green material.However,WPU has poor water resistance and mechanical property,which has restricted its application in various fields.To enhance its property,fluorinated monomer and cross-linking agent are used to modify WPU,with the aim to obtain safe,environment-friendly products with excellent performance and synthesis.In this essay,polytetracyanuran ether glycol?PTMG?and isoflurone diisocyanate?IPDI?are used as the main raw materials to synthesize waterborne polyurethane,and a series of fluorinated waterborne polyrethane?WFPU?is synthesized by introducing C₆H₆O₂F₈,C₄H₃F₇O and C₁₀H₅F₁₇O as the modifying agents.The influences of different locations of fluorinated monomer in the main chain of the polyurethane and different lengths of the carbon chain of the fluorinated monomer on the mechanical properties and water resistance of the waterborne polyurethane are studied.It is found through tests of viscosity,particle size,infrared spectroscopy,XPS,water resistance and SEM that addition of fluorinated monomer can enlarge emulsion particle size,reduce the viscosity and improve its water resistance and mechanical property.In addition,the surface contact angle of the C₁₀H₅F₁₇O modified waterborne polyurethane film that is connected to the end of the polyurethane chain with longer carbon chain reaches 105.4^o,and the tensile strength can reach 29.06 Mpa.A series of cross-linking modified fluorinated WPU are synthesized with castor oil?C.O.?,trimethylolpropane?TMP?as the cross-linking agents and C₁₀H₅F₁₇O as the fluorinated monomer to study the influence of cross-linking agent on WFPU,and it is found that addition of C.O.and TMP can improve the mechanical property of WFPU and lower water resistance of cellophane surface.Compared with WFPU modified with TMP,the mechanical property of WFPU modified with C.O.and test results of water contact angle of the cellophane are good,and the tensile strength of WFPU containing 5%C.O.can reach 44.40MPa.