Preparation And Properties Of Waterborne Polyurethane/Inorganic Filler

The waterborne polyurethane(WPU)has been applied in many fields due to its unique molecular structure and excellent properties.WPU has become necessary for development after solvent-based polyurethane brought great pressure to the environment.However,there are still many problems in the use of unmodified WPU materials,such as low material strength and poor water resistance.Therefore,it is feasible to introduce inorganic fillers into the matrix of waterborne polyurethane to modify it in order to obtain the waterborne polyurethane material.This method can improve the comprehensive properties of the polyurethane material.In this paper,organic montmorillonite(OMMT)and modified graphene oxide(FIGO).The modified Hummers method was used to oxidize the expandable graphite to prepare GO,and GO was modified by isophorone diisocyanate(IPDI)and trimethylolpropane(TMP)to prepare FIGO.FT-IR was used to characterize GO and FIGO.By using FIGO and OMMT to prepare FIGO/WPU,FIGO/PVP/WPU and OMMT/WPU,OMMT/PVP/WPU composite emulsions(F/W,F/P/W,O/W,O/ P/W).The effects of FIGO and OMMT content and PVP on the stability of composite emulsion and the mechanical properties,water resistance and thermal stability of composite materials were studied.Scanning electron microscopy(SEM)showes that different contents of fillers are dispersed in the matrix and PVP can enhance the bonding strength of the matrix with the filler and make the filler evenly dispersed.Thermal weight loss(TGA)indicates that the thermal stability of the composite material is improved compared to pure WPU.Both modified fillers can improve the water resistance of the composite material.With the same content of FIGO and OMMT composite materials,the water blocking effect of OMMT composite materials is more obvious.Both FIGO and OMMT can improve the mechanical properties of the composite material.Among them,the F/W-4 tensile strength is 43.48 MPa,and the O/W-4 tensile strength is 41.34 MPa.Therefore,the same content of FIGO and OMMT composite materials,the mechanical property of FIGO composites has better reinforcement effect.Using PVP modified composite materials to study the impact of PVP on composite materials.The results show that PVP can promote the stability of the emulsion and the dispersion of the filler in the matrix;increase the bonding strength of FIGO with OMMT and PU matrix;improve the elongation at break of the composite;the hardness reaches 4H,and the adhesion level is 0.On this basis,the content of inorganic filler with the best performance of FIGO composite and OMMT composite was determined.According to this content,the preparation and research of the FIGO/OMMT compounding system are designed in proportion.From the previous chapter,it is known that PVP can improve the tensile strength,elongation at break,hardness and adhesion of the material,so the content of this chapter is only the FIGO/OMMT/PVP/WPU composites(F/O/P/W).Compared with the single-component filler composite emulsion,the appearance of the prepared two-component filler composite emulsion is very different,of which the F/O/P/W-2,2 composite emulsion has the best comprehensive performance: the emulsion has good stability and almost no precipitation;the tensile strength of the two-component composite material is higher than that of the single-component composite material,of which the tensile strength of the F/O/P/W-2,2 composite material is 51.27 MPa;the water resistance is greatly improved;Thermal stability is improved.It can be seen from the SEM that the filler in the two-component composite material is coated in the matrix,indicating that the inorganic filler has a high bonding strength with the matrix.