Optimizating The Synthesis Process Of Alkyl Aluminum Phosphate And Applying IT In The Thermal Insulation Material

This paper researches the effects of productive rate in different reactiveconditions which is based on the existing ADP synthesis method in order to optimizethe whole reaction process. After this, we add the ADP into the thermal insulatingmaterials named EPDM and108-2and then determine the ablation resistant propertiesand mechanical properties of the thermal insulation material in regulating the differentpoints of formula.In the first part, the synthesis of ADP uses sodium hypophosphite, ethylene andaluminum sulfate as the raw materials, and tert-Butyl peroxybenzoate (TBPB) andbenzoyl peroxide (BPO) as the initiator. By adjusting the ratio of TBPB and BPO,reaction temperature and pressure under different conditions, we caculate the yield ofADP. At last, the synthesis yield of ADP reached to the maximum which is97.3%when the ratio of BPO and TBPB is1:1, temperature is95℃, pressure is7Bar andthe reaction time is5h. After that, we determine the structure characterization of thesynthesis ADP by using infrared spectroscopy(FTIR), solid nuclear magneticresonance spectrum(31P-NMR), thermogravimetry(TG), X ray photoelectronspectroscopy (XPS). At the same time, the particle size analyzer and density analyzerare carried out on determining the physical properties of the synthetic ADP.In the second part, the EPDM rubber insulation material formulation wasoptimized based on the existing formula. The changes of linear ablation rate, backtemperature, carbon layer structure and mechanical property in ablation time (10s,20s,40s and60s) is by adjusting the content of flame retardant (such as ADP, ADP+OPS,ADP+OAPS, ADP+PPSQ) and functional additives (such as aramid pulp, aluminumacetylacetonate). The elongation and the tensile strength of EPDM which addcomposite flame retardant ADP+OPS are220%and8.75MPa. Not only this, thelinear ablation rate reached to the lowest0.029mm/s and the back temperature is47.5℃in the ablation time60s. At the same time, the densification degree of carbonlayer continues to improve, and aperture appears decreasing from outside to insidewith the increasing of ablation time.In the third part, the effect of flame retardant in the formulation is studied addingto the room temperature vulcanized silicone rubber (108-2). Comparing the ablative performance and mechanical properties of thermal insulation material in differentflame retardant (ADP, ADP+OPS, ADP+APP/6%MMT), the linear ablation ratereached a minimum of0.073mm/s in ablation time of60s which is added ADP onlyand the best mechanical properties is adding25g ADP and12g OPS whose fractureelongation is just113%and the tensile strength is2.67MPa.