Preparation And Properties Of Polyaniline Modified Waterborne Polyurethane/Acrylate

In today’s vigorous promotion of environmental protection,the hazards of noise pollution have received great attention,and the safety hazards around are gradually increasing,and the functionalization of materials has gradually become a hot topic today.Polyurethane(PU),as an important damping material,has been widely used in rail trains,aerospace,automotive industry,etc.However,most commercially available damping materials are mainly asphalt-based and solvent-based,which contain more organic solvents and bring inevitable environmental pollution and harm to human health during preparation and use,while solvent-free water-based polyurethane(WPU)can effectively the solvent-free WPU can effectively avoid such problems.However,in actual production life,the poor water resistance,strong insulation,and flammability of WPU easily bring safety hazards and threaten people’s life and property,which makes its application area only limited to certain fields,so it is especially important to develop a water-based damping coating with water resistance,antistatic type,and flame retardant type,based on this paper,the functionalization of WPU was studied from the following aspects.(1)Waterborne polyurethane/acrylate(WPUA)composite emulsions with core-shell structure were prepared by emulsion polymerization using diisocyanate,oligomeric diols,chain extenders,crosslinkers,initiators and acrylate monomers as raw materials.Conductive polyaniline(PANI)was prepared by chemical oxidation method and added to WPUA composite emulsion to produce aqueous polyurethane/acrylate-polyaniline(WPUA-PANI)emulsions with different PANI contents.Infrared analysis revealed that the hydrogen bonding between PANI and WPUA molecular interfaces,and the hydrogen bonding enhanced with the increase of PANI content,resulting in complex molecular chain entanglement,intermolecular friction,and motion hysteresis.Using the characterization means such as contact angle test apparatus(DSA),digital high resistance meter and dynamic viscoelastic spectrometer(DMA),it was learned that when the PANI dispersion content was35%,the water contact angle,tensile strength and resistivity were 106.8°,2.31 MPa and 3.47×10~4Ω·cm,respectively,and the effective damping temperature domain(Tanδ≥0.3)increased from 50℃to 87℃.The WPUA-PANI film has the best overall performance.(2)A series of WPUA damping coatings with antistatic and flame retardant properties were prepared by adding damping fillers,flame retardant fillers and additives to the WPUA-PANI emulsion with excellent overall performance as the base emulsion.The water contact angle and resistivity were 110.9°and 7.24×10~4Ω·cm,respectively,when the sericite content was 30%.the maximum effective damping temperature range value(Tanδ≥0.3)was 122℃,which was a large improvement over the base emulsion.After fixing the addition of sericite,the effective damping temperature range,resistivity,and ultimate oxygen index of the coating were 138℃,9.52×10~4Ω·cm and 30.4%respectively when the content of flame retardant filler Doher-6003 was 20%,and the coating had good damping,antistatic and flame retardant properties.The rheological performance test,pencil hardness,cross-cut test,and media immersion test show that the prepared coatings are pseudoplastic fluids with good anti-sagging,suspension,and anti-corrosion properties,and can be widely used in many fields.