Study And Application Of The Halogen-free Flame-retardant Waterborne Polyurethane

Now, waterborne polyurethane coatings as a new environmentally friendly paint coatings are widely used in textile finishing, but textiles and as a coating of waterborne polyurethane finishing agent are all inflammable materials, In order to increase added value and to meet the special needs of the flame retardant textiles aspect, this is a major research topic retardant modified waterborne polyurethane, then fire-retardant modified waterborne polyurethane coating agent is applied to textiles to achieve the purpose of flame retardant textiles.A series of reaction flame retardant waterborne polyuerthane were synthesized,which were modified with the phosphorus(P) reactive flame retardant[(bis(2-hydroxyethyl) amino) methyl] diethyl phosphate(FRC-6), isophorone diisocyanate(IPDI),polypropylene glycol(PPG) and dimethylol propionic acid(DMPA)were used as the basic monomer, then testing and characterization of waterborne polyurethanes were synthesized. Meanwhile, in order to improve performance, added ammonium(APP-MEL-PER) in the synthesis of aqueous polyurethane composition of intumescent flame retardant system and flame retardant synergist to prepare complex mixed aqueous polyurethane flame retardant coating agent is applied to the fabric coating finishing.The experiment analyzed the factors of R value, dosage of a flame retardant(FRC-6), dosage of DMPA,the of time and temperature of prepolymerization and extender chain, The best synthesis process was that-NCO/-OH molar ratio is 1.8,FRC-6 usage is 20%, DMPA uasge is 4%,the temperature and time of was 80 ℃ and2 h,the temperature and time of chain extension was 65 ℃ and 1.5h.The experiment ensured intumescent flame retardant system APP: MEL: PER ratio is 30:20:15, a flame retardant quality is the mass of polyurethane 30%, silicone synergistic agent simethicone dosage and inorganic flame retardant synergist magnesium hydroxide Mg(OH) 2 dosage were 4%(as a percentage of the total mass of fabric fire-retardant coating agent), the drying temperature and time of coating finish is 90 ℃ × 3min,baking temperature and time is 140 ℃ × 2min.Studies showed that adding FRC-6 decreased water resistance of polyurethane,vertical combustion test showed the reactive flame retardant waterborne polyurethane also have some flame retardant properties to fabrics.Reacting flame retardant waterborne polyurethane including phosphorus was characterized by the Fourier transform infrared spectroscopy IR and energy spectrum that showed the element phosphorus(P) was successfully incoming into the waterborne polyurethane molecular chain, by gel chromatography analyze showed that molecular weight of the flame retardant flame polyurethane centralized distribution and relatively stable nature; by thermogravimetry analysis tests(TG-DTA),thermostability of polyurethane was improved after the addition of a reactive flame retardant FRC-6, and its flame retardancy was promoted. Scanning electron microscopy(SEM) show the waterborne polyurethane flame retardant is evenly covered with the fabric surface,the ash after burning showed that flame retardant had the flame effect. After fabric flame retardant finishing of polyester fabric and unfinished compared to polyester fabric,finishing fabric has excellent flame retardant properties.it is worth further study.