Synthesis Of Fluorinated Acrylate Modified Waterborne Polyurethane

In recent years,various environmental protection regulations have been gradually introduced,people attach more and more importance to the environment,polyurethane(PU)can not meet the requirement of healthy and environmental protection because there are a large number of organic solvents.Therefore,waterborne polyurethane(WPU),which has less environmental pollution,emerged as the times require.However,WPU has the disadvantage of poor water resistance,heat resistance and mechanical properties.In order to improve its properties,we modified it with fluorinated acrylate(FA)to obtain excellent products with good properties,safety and environmental protection.The experiment adopts polytetramethylene glycol(PTMG),isophorone diisocyanate(IPDI),dimethylol propionic acid(DMPA)as the main raw materials,2-hydroxyethyl methacrylate(HEMA)as grafting agent,a series of FA modified waterborne polyurethane emulsions(WPUFA)were synthesized with octyl ethyl acrylate(FA)as a modifier and cured into a film.The effects of HEMA content and internal structure on the properties of emulsion and film were investigated,and characterized by FTIR,optical properties,contact angle,mechanical properties,thermogravimetric analysis(TGA)and scanning electron microscopy(SEM).(1)The WPUFA emulsion with different HEMA content was synthesized.It was found that the HEMA content had a certain influence on the properties of the formed emulsion and film,and when the content of HEMA was small or excessive,the comprehensive properties could not be achieved at the same time.Only when the molar ratio of HEMA to-NCO group was the same,The obtained product is ideal.(2)A series of WPUFA emulsions with different FA contents were synthesized and characterized to find that the FA content had a great influence on the properties of the modified emulsion and film.With the increase of FA content,the particle size of the emulsion particles becomes larger,the viscosity becomes lower,and the water resistance,mechanical properties,and heat resistance of the film have been improved to varying degrees,but the light transmittance has deteriorated.Through the SEM image,the phase separation of the film after the addition of FA can be clearly observed.With the increase of FA content,the phase separation phenomenon in the rubber film will be more obvious.At the same time,the effects of film forming temperature and post-treatment temperature on the surface properties of the film were tested.he results show that the contact angle increases when the film temperature and heat treatment temperature increase,but the contact angle does not continue to increase.When the temperature reaches a certain level,the contact angle does not increase but decrease.(3)Three kinds of WPUFA emulsion with different structure were synthesized by different reaction methods.It was found that the emulsion with WPU-FA crosslinked structure had small particle size,excellent mechanical properties and heat resistance,and low water absorption,but the contact angle was smaller than that of non-crosslinked structure.The contact angle of non-crosslinked emulsion is larger,but it's mechanical properties are poor.However,the emulsion and film properties of WPU self-crosslinking structure did not show outstanding properties.