Synthesis And Performance Study Of Hydroxyl Terminated Poly-Phosphonic Ester

Oligomer polyol is an important raw material for chemical industry, According to the different types of polyols, they can be made into various resin products, such as foam, adhesives, coating, elastomers, etc. With the growth of the needs of various resin products’ application, people have developed different kinds of polyols,improving performance of resin products constantly, expanding application scope, and enormously promoting the development of various resin materials. In which resin materials are flammable and it become a hot topic of current researches to improve their flame-retardant properties.In this work, a kind of phosphonium flame-retardant polyols was synthesized, structure with hydroxyl terminated poly-phosphonic ester, dimethyl methylphosphonate(DMMP) and ethylene glycol (EG) as raw material, dibutyltin dilaurate as catalyst. The synthetic product structure was represented by IR, NMR analysis, product molecular weight was measured through GPC.The factors influencing the reaction,such as the molar ratio of the amount of the catalyst, the reaction temprature,the reaction time, the molar ratio of raw materials were studied,and therefore synthetic technology was determined as follows:when the dibutyltin dilaurate was0.2wt%,the reaction temprature was between175-185℃,the reaction time was about5h,the molar ratio of EG to DMMP was1.19, hydroxyl terminated Poly-phosphonic ester with1049of molecular weight was obtained. In addition, as one of the components of polyols, phosphorus polyurethane was prepared, and phosphorus oxygen key was introduced into molecular structure of PU by infrared spectral analysis, mechanical properties of PU samples with different phosphorus content were tested, flame retardant performance was characterized through its limit oxygen index(LOI), and the stability of thermal oxidation was evaluated through Thermogravimetic Analysis and flame-retardant mechanism was analysed on the phosphorus components used in polyurethane.The results showed that as the addition of the hydroxyl terminated poly-phosphonic ester, the break elongation gradually increased, the tensile strength declined at some level, and LOI gradually rised; when the contents of the hydroxyl terminated poly-phosphonic ester were respectively4.43%、9.74%、13.14%,the break elongations of PU increased by8.86%、23.3、32.2%,LOI respectively was achieved27.6、29.8、30.7; it can be proved that phosphorus PU had good flexibility and processability,and flame retardant effect was excellent.