Preparation,Modification And Application Of Sulfonated Polyether Waterborne Polyurethane

Polyurethane(PU)has been widely used due to its adjustable structure and excellent performance.It has excellent wear resistance,high strength,high adhesion and adhesion,and is considered to be one of the most versatile polymer materials.Based on strict environmental and legislative requirements,Waterborne Polyurethane(WPU)has received increasing attention due to the advantage of being environmentally friendly,cost-effective and low toxicity.The most widely used research is anionic WPU(carboxylate and sulfonate).Among them,the sulfonate WPU with better performance is a hot research direction at home and abroad,not only has excellent hydrolytic stability in a wide pH range,but also has high solid content of the emulsion and adhesion strength to the substrate andwide application.In this paper,the preparation and modification of polyethersulfonate WPU are mainly studied.In the second chapter,a series of polyether sulfonate WPU emulsions were prepared by using polyether polyol(PPG,PTMG)as soft segment and sodium ethylenediamine sulfonate(A95)as hydrophilic chain extender.The effects of A95 content,hard segment content(H%)and soft segment on SWPU emulsion and film were discussed.Through basic tests,the results show that the A95 content gradually increases,the water absorption rate of the film gradually increases,and the mechanical strength increases due to the increase of strong polar groups such as urea bonds;while the H%increases,the solid content of the emulsion increases,and gradually increase the water resistance and mechanical strength of the film,but the heat resistance is slightly reduced;when the molecular weight of PPG is increased from 1000 to 3000,the appearance of the emulsion gradually becomes opaque,and the heat resistance of the film is improved,and the mechanical strength is gradually reduced.And the water resistance,mechanical properties and heat resistance of PTMG as soft segment SWPU film are significantly higher than PPG.When the A95 content is 2.0%and the H%is 36.8%,when the PPG molecular weight is 2000,the viscosity and particle size of the obtained emulsion are moderate,and the comprehensive performance of the film is the best.In the third chapter of this paper,cellulose nanocrystals(CNC)were modified with toluene diisocyanate(TDI80/20),and then the modified CNC was incorporated into SWPU to synthesize CNC modified SWPU composites.The effects of modified CNC addition on the properties of SWPU emulsion and film were studied,and the application of SWPU as a water-based binder in lithium ion batteries was studied.The mechanical,thermal and electrochemical properties of the composites were characterized by infrared(FT-IR),X-ray diffraction(XRD),tensile machine,thermogravimetric(TGA),battery cycle,and magnification.The results show that the addition of modified CNC significantly increases the mechanical strength and heat resistance of the composite.When the amount of modified CNC added was 1%,the tensile strength reached 26.01 MPa.The battery with SWPU3 as a binder had a capacity retention ratio of 97.9%after 60 cycles compared to the first time.In the fourth chapter of this paper,a series of blended emulsions of polyethersulfonateWaterborne Polyurethane and Acrylate(SWPUA)were prepared by physical blending.A series of sealants were synthesized based on SWPUA composite emulsion and heavy calcium carbonate(CaCO3)as filler.The effects of PU/PA ratio and filler content on the surface time,mechanical properties and bonding properties of the sealant were investigated.The results show that the mechanical properties and bonding properties of the sealant gradually decrease with the increase of PA dosage.As the amount of heavy CaCO3 added to the filler increases,the sealant strength decreases.When PU/PA is 3:7,when the filler is added at 50%,the tensile strength of the sealant is 3.19 MPa,the tensile shear strength is 0.45 MPa,the tensile bondability is 0.48 MPa,and the comprehensive performance is best.