Synthesis Of Aluminium Hypophosphite Flame Retardant And Its Application In Polypropylene

Polypropylene?PP?is one of the most widely used thermoplastic plastics.Because of its versatility and high cost performance,the PP materials have been widely used in many fields.While because of the content of carbon and hydrogen in PP is relatively high,the polymer is easy to burn,and the combustion process will produce intense flame,also generate a lot of heat,there is a certain extent phenomenon for droplet occurred to drop.These factors will cause some obstacles for the PP material in the application.Therefore,the research and development about in the flame retardant PP material which has excellent flame retardant properties and mechanical properties is a pressing matter of the moment,expand its application as an important engineering plastics,in order to increase the value of the product,and provide better materials for industrial production and people's life.While aluminium hypophosphite?AHP?is an inorganic phosphorus series flame retardant with high flame retardant properties and good thermal stability.As the PP material has various shortcomings in the actual application,this paper have done some relevant research from the two aspects:Synthesised and characterized with AHP which has high phosphorus content,then added AHP to PP according to different proportions in order to improve its flame retardant properties.The main research contents of this paper are as follows:1.AHP was synthesized by co precipitation method,and put anhydrous ethanol as the solvent for the raw materials anhydrous aluminum chloride,to reduce the solubility of product AHP in the reaction solution,while these measures will also make the impurities Na⁺and Cl^-which come from the synthetic products dissolved more in the reaction solution,in order to improve the productivity and purity of the product.Meanwhile the experiment adopted three synthetic methods to synthesis the AHP and was characterized respectively.Then we have controlled the the ratio of amount of substance concentration of the reaction materials to study the performance and the productivity of the product.The synthesized products were respectively confirmed by Fourier transform infrared spectroscopy,X-ray diffraction experiment test,thermogravimetric analysis and differential thermal analysis test,scanning electron microscopy,X-ray photoelectron spectroscopy test,X-ray fluorescence and other related test,relevant data show that,three methods could be synthesized the AHP.When the ratio of amount of substance concentration of sodium hypophosphite and aluminium chloride?C₁:C₂?is 8:1,the synthesized product which was producted by the first experimental method has the maximum productivity in the all products,up to 92.7%.At the same time,the phosphorus content of the product is relatively high,meanwhile the content of impurities which is most constituted from Na⁺and Cl^-is relatively low.The particle has smaller size and good dispersion.The thermal stability of AHP is really good,and is higher than the decomposition temperature of PP material,and is suitable for added to PP material,and have no adverse effects on its decomposition.2.Then we put the flame retardant AHP which was synthesized into PP material according to different ratio,through mixing and pressing into a series of flame retardant composites,and the material have been tested by the limiting oxygen index text,vertical burning test,mechanical properties test,processing performance test,thermal performance test and SEM test and other tests.According to the results,when the addition of AHP is 24%,the limit oxygen index of flame retardant PP material system is 31.2,and the vertical combustion rating can reach V-1 level,while it has satisfied mechanical properties and processing performance,meanwhile the thermal stability and carbon residue rate of the material are significantly improved compared with the pure PP materials.