| Polyester(PET)fabric is the largest synthetic fiber with excellent performance and wide application.It has many advantages such as high strength,good wear resistance,chemical corrosion resistance and so on.However,the flammability of PET fabric also brings fire risks in use.In this paper,a simple and efficient coating process was employed to obtain environmental friendly flame-retardant polyester fabric.The fire performance and moisture absorption of polyester fabric were improved by the presence of several different and efficient coatings,meanwhile,the static electricity and environmental pollution were reduced,which further expanded the application field of polyester fabric.The mechanism of flame retardant was also analyzed.The main outcomes are as followings:Firstly,a waterborne acrylate emulsion containing silica sol coated ammonium polyphosphate(Si-APP)and melamine(Mel)was coated on the surface of PET fabric.The test results showed that the limiting oxygen index(LOI)of PET fabric increases from 18.9 to 26.2 when Si-APP was 17wt%and Mel was 5wt%,and the damage length reduced to less than 10cm.The silane coupling agent in silica sol effectively improved the compatibility between flame retardant and matrix and acrylic acid,and improved the mechanical properties of PET fabric.Silica-sol and phosphorus nitrogen flame retardant played a synergistic role in reducing the fire spread rate of PET fabric,resulting enhancement of the thermal stability of the fabric.The inorganic layer formed by silica sol at high temperature was covered on the surface of the carbon layer,which significantly improved the stability of the carbon layer.Secondly,PET fabric coated with biomass polyelectrolyte chitosan(CH),sodium alginate(SA)gel and sepiolite was obtained through layer by layer self-assembly technology.The results showed that the coated PET fabric has excellent charring property,and the amount of carbon residue can reach 24.0%at 700℃.At the same time,the LOI of PET fabric with 9BL and the concentration of polyelectrolyte was 1wt%reached 27.4.The carboxyl group and hydroxyl group on the molecular chain of alginate and chitosan made the system obtain good charring ability,also released H2O and NH3 in the gas-phase auxiliary flame retardant.Sepiolite intercalated in the carbon,playing the role in thermal insulation and enhancement of carbon layer.Several components of the coating cooperated with each other,effectively prevented the ignition and burning of the coated PET fabric,prevented the emergence of dripping.The introduction of these polar groups also improved the moisture absorption of PET fabric and antistatic capacity.In addition,the self-assembled coating PET fabric also showed water resistance.After soaking in water for 1 h,it still had a good fire resistance with a LOI value of 25.0.Finally,sodium alginate was used as a carbon forming agent.Sodium alginate,ammonium polyphosphate,silica sol and long-chain silane coupling agent were used as composite coatings.After coating,the expanded carbon layer with inorganic silicon was formed.The flame retardant coating increased the LOI of PET fabric to 30.3 and the flame was extinguished without any dripping after the removal of the ignitor.The addition of superhydrophobic coating did not damage the flame retardancy of PET fabric.The coated fabric had a water contact angle of more than 150° and showed excellent water repellency and self-cleaning ability,which can be used to separate organic solvent and aqueous solution... |
PDF Full Text Request