Synthesis, Characterization And Application Of Hyperbranched Expansion Flame Retardant

Hyperbranched molecule has most of the advantages:the characteristics ofmulti-branches, many hydroxyls, high reaction activity and low viscosoty. At thesame time, it is relatively simple that the synthesis of hyperbranched moleculehas less steps, loose synthetic conditions and low cost. So, it has attracted manyattentions and obtained big progress in the past few decades. In view of manyspecial advantages of hyperbranched polymers, the modification ofhyperbranched polymer which extends the special functions and applicationscope become be active in the field of scientific research. According to thehuman needs, the modification at the hyperbranched molecule end group makesits flame retardant properties, which is a new discussion on the applications ofhyperbranched polymers.The waterborne polyurethane (WPU) which takes the water as thedispersion medium has the advantages of slight smell, non-pollution, energysaving and so on. The PU is flammable material, may result in significantcasualties and property loss. Therefore, the flame-retardant treatment to the WPUis necessary.Halogen flame retardants can release toxic gas that does not meetenvironmental requirements. As the important species of halogen-free flameretardant, phosphorus and silicone flame retardant have aroused widespreadattention as the environmental protection was advocated in the world.In this thesis, based on the hydroxy of hyperbranched molecule research, anew type of phosphate compounds was prepared with a modification at thehyperbranched molecule end group. And it was used in waterborne polyurethaneto investigate the influence on material properties and flame retardant effect.In this issue, we firstly synthesized the AB2monomer from the initialmaterials methylacrylate and diethanol amine. After that, we prepared onegeneration hydroxyl-terminated hyperbranched polymer (HAPE1) by using “quasi one-step”, with trimethylolpropane as its core. And then, a suitablephosphorylation agent that selected and prepared before reacted with HAPE1and the hyperbranched expansion flame retardant (HAPE1-P) was synthetizedsuccessfully. In this experiment, the reaction conversion rate was determined bypotentiometric titration, taking this as the standard, the phosphorylation agent,reaction time, reaction temperature and the amount of catalyst were optimized inthe help of single factor experiment method. Finally, the last three factors werestudied by orthogonal experiment to discusse the influence of the factors and theoptimum experimental conditions were determined. The experimental resultsshowed that the optimum conditions of the synthesis were that the molar ratio(based on P) of phosphorus and phosphoric acid was2:1in phosphorylationagent, the reaction time was4h, the reaction temperature was80℃, the amountof catalyst was1.1%. The structure of hyperbranched expansion flame retardantwas characterized by IR, elemental analysis, nuclear magnetic methods. Formthe IR spectra of the HPAE1-P, we could know that a phosphate esterificationhad done smoothly while the characteristic absorption peak of hydroxylweakened and the characteristic absorption peak of P-O-C appeared. On theother hand, the elemental analysis results from the chemical content proved it.The31P-NMR spectrum was further proved that the reaction mainly producedphosphate monoester. The TG analysis showed that the thermal stability ofHPAE1-P was very good and it could be used in many polymers.We prepared an appropriate solution with hyperbranched expansion flameretardant (HAPE1-P), investigated the stability of emulsion, the materialproperties, solvent resistance, OI, smoke density, vertical combustion while thesolution were used in a representative water-borne polyurethane such asMWU-TG-902and MWU-T-502B, and tried to discuss the related reasons. Theresults showed that the flame retardant with MWU-TG-902and MWU-T-502Bhad good compatibility, could make the material physical properties decreaseslightly, had little effect on the solvent resistance of the material, couldsignificantly improve the flame retardant properties. With respect toMWU-TG-902, the sample of the OI rose to25.9%, went up41.5%when theaddition of HAPE1-P was18%; the sample of the most great smoke density roseto39%, went down25.0%when the addition of HAPE1-P was6%; the flame retardant grade could up to UL-94V-2when the addition of HAPE1-P was9%.With respect to MWU-T-502B, the sample of the OI rose to27.3%, went up56.0%when the addition of HAPE1-P was18%; the sample of the most greatsmoke density rose to29%, went down54.0%when the addition of HAPE1-Pwas12%; the flame retardant grade could up to UL-94V-1when the addition ofHAPE1-P was15%.