Preparation And Properties Of Halogen-free Flame Retardant Waterborne Polyurethanes Modified By Caster Oil

In today's increasingly serious global environmental problems,waterborne polyurethane(WPU)as an environmental-friend material with excellent performance,non-toxic and non-pollution has attracted more and more attention.However,the waterborne polyurethane itself is a flammable material,which makes it have a certain fire hazard in the actual application process.Therefore,the flame retardant modification of WPU has become an important direction of its functionalization.Currently,the modification of waterborne polyurethane mainly introduces flame retardant into its system by chemical reaction method,but this also changes the original chain structure of polyurethane to a certain extent,which has a certain impact on the performance of WPU.In this thesis,it started from explored the impact of flame retardants on WPU performance,the performance of soft and hard segment co-modified flame retardant waterborne polyurethane was analyzed,and the mechanical properties and water resistance of the decline were modified and studied.This study is based on isophorone diisocyanate and polytetramethylene ether glycol as the basic reaction raw materials,phosphorus flame retardant(Exolit OP550)and N,N-bis(2-hydroxyethyl)diethyl amino methylene phosphonate(FRC-6)was used as a soft and hard flame retardant modifier to synthesize a series of halogen-free flame retardant waterborne polyurethane.The effects of the amount and proportion of flame retardant on its emulsion properties,mechanical properties,water-resistance and flame retardant properties were investigated.The study found that when the content of flame retardant increases,the particle size of the emulsion increases,the viscosity and surface tension decrease;the mechanical properties and water resistance of the film both decrease significantly,and the FRC-6 content has a more obvious effect on the mechanical properties of the film,OP550 affects the film The effect of decreasing water resistance is greater;the flame retardant performance of the film is improved due to the increase in the content of the flame retardant,however,the flame retardant performance caused by the droplets in the combustion process is affected to a certain extent.Combined with the above research results,castor oil(CO)was used as a cross-linking modifier to introduce it into the flame retardant waterborne polyurethane system together with the quantitative silane coupling agent KH-550 to synthesize a series of castor oilmodified flame retardant waterborne polyurethane.The effects of CO dosage and the introduction of KH-550 on the properties of flame retardant waterborne polyurethane were studied.The study found that the introduction of KH-550 can improve the mechanical properties and water resistance of the film to a certain extent,and as CO begins to be introduced,this improvement effect is more obvious.When the CO content is 7 wt%,the tensile strength of the film increases from 11.19 MPa to 20.24 MPa,and the water absorption rate eventually decreases by 102.24% with the increase of the CO content.In addition,due to the introduction of the cross-linked structure,the material's droplet phenomenon is reduced,the flame retardant performance is improved,and the LOI finally reaches 25.0%,and UL-94 rises to V-1 level.