Study On Synthesis And Properties Of Phosphorus-containing Waterborne Polyurethane

Functional polyurethanes add specific molecular structures or elements to the polyurethane molecular structure to give the polyurethane excellent properties.Phosphorus because of its hydrophilic,flame retardant,it can be used as functional monomer synthesis of flame-retardant functional water-based polyurethane.The study will help to broaden the application of waterborne polyurethane and make full use of the excellent properties of waterborne polyurethane.In this paper,the optimum conditions for the synthesis of phosphorus-containing diols and phosphorus-containing triols were determined,and the phosphorus-containing polyols were characterized.As a hydrophilic chain extender phosphorus-containing diols prepared excellent flame retardant properties of water-based polyurethane.As the post-chain extender phosphorus-containing triol,the water-borne polyurethane with excellent flame retardancy was prepared.Adding a small amount of MCA and phosphate can improve the flame retardant effect,while the mechanical loss is small.The phosphorus-containing diols were used as post-chain extender to prepare polyurethane aqueous solution with good flame retardancy.Firstly,two kinds of phosphorus-containing flame-retardant polyols were synthesized by using dimethyl phosphate(DMMP),trimethyl phosphate(TMP)and 1,4-butanediol(BDO).The experiment was carried out to determine the optimum synthesis process.Secondly,flame retardant functional waterborne polyurethane with good performance was prepared by using phosphorus-containing diols and phosphorus-containing triols.Phosphorus-containing diols can be used as hydrophilic chain extenders.When it is added at 13%,the oxygen index(LOI)is increased from 18%to 25%and the flame retardant rating is UL-94 VTM-0.Phosphorus-containing triols can be used as post-chain extenders.When its content is 5%,LOI from 18%to 23.5%,flame retardant grade reached the UL-94 VTM-1 level.Phosphorus trihydrin is added in an amount of only 5%,which is better than other additive flame retardants.When the amount of MCA is only 5%,the LOI can reach 26%and the flame retardant grade is UL-94 VTM-0.Phosphate is only 5%,LOI can reach 28%,flame retardant grade UL-94 VTM-0.Finally,a phosphorus-containing aqueous polyurethane solution was prepared using a phosphorus-containing diol as a post-chain extender.Increase the proportion of phosphorus-containing diols,water-based polyurethane from opaque emulsion into a translucent dispersion,and finally into a transparent aqueous solution.When adding 10%phosphorus-containing diol,the phosphorus-containing polyurethane aqueous solution is clear and transparent.The LOI of the waterborne polyurethane is 23%and the flame retardant rating is UL-94 VTM-1.Flame retardant performance has been effectively improved.