Synthesis Of Phosphate Ester Flame Retardant BDP And Study On Halogen-free Flame Retardant PPO/HIPS Alloy

As one of the five largest general engineering plastics, Thermoplastic resin Polyphenylene oxide (PPO) was developed by the General Electric Company (GE) in the mid 60s,20th century. Although PPO has excellent physical and mechanical properties, heat resistance and electrical insulation, it has defects such as high viscosity, poor mobility, very sensitive to notch. So it needs modification. Usually the modification is blend polyphenylene oxide with polystyrene, especially high impact polystyrene. Polyphenylene oxide has a good flame retardant property and its an extinguishing resin. But high impact polystyrene is a flammable materials, the alloy of the two has a weak flame retardant property. Because of these reasons, we need to add some suitable flame retardants on the ally to improve its flame retardant property. Commonly, the most used flame retardants are halogenated and phosphorus flame retardants. Halogenated flame retardants generate a lot of smoke and corrosive gases or even highly toxic dioxins during the combustion process. Some countries in the European Union have enacted laws to prohibit the use of such flame retardants.Phosphate ester flame retardants has been used in polymers for many years. With the development of the flame retardants research, phosphate ester flame retardants have been changed from single phosphate ester to polyphosphate. Especially the oligomer of double phosphate. They have advantages of symmetrical structure, high molecular weight and high phosphorus content. They are good plasticizers which are better than normal phosphates in flame resistance and thermal stability. They have good compatibility with polymers and had been widely applied. Bisphenol A bis (diphenyl phosphate) (BDP) is an outstanding representative in such flame retardants. There has industrial products abroad, while in China its still under development and has no industrial products.In this paper, environmental protection and high efficient Halogen-free flame retardant bisphenol A bis (diphenyl phosphate) (BDP) was synthesized first. We found the most appropriate synthetic route and reaction conditions for BDP, and improved post-processing methods and techniques to increase raw materials and energy's utilization rate so as for the preparation of large-scale industrial production of BDP. Then we added BDP to the PPO/HIPS alloy to improve its flame retardant property, the results show that the BDP has good flame retardant property to the alloy, it has a small mechanical property loss to the material and can improve the processability of the alloy; After that we used another two less expensive halogen-free flame retardants which are nitrogen containing and inorganic flame retardants on PPO/HIPS alloy and found that the effects of the other two flame retardants are just so so. They have a big impact on alloy's impact strength and its processability. In order to improve the flame retardant efficiency, compounding method was used finally. The other two flame retardants were compounded with phosphorus flame retardant. It was founded that the compounding method can improve flame retardant efficiency and cost less than phosphorus flame retardant. What's more, compounding method can reduce mechanical property and processability loss of PPO/HIPS alloy. Comparison shows that the best way is using modified kaolin compounded with BDP.