Microencapsulation of Ammonium Polyphosphate in Different Volume Ratios of Water and Alcohol and Its Flame Retardance in Polypropylene

Melamine-formaldehyde resin microencapsulated with ammonium polyphosphate (MFAPP) was prepared by in situ polymerization.The influence of volume ratios of water and alcohol on the encapsulation of APP and the effect of MFAPP on the flame retardance in PP were investigated.The MFAPP was characterized by solubility measurement,FT-IR,TG,SEM.The effect of microencapsulation on the flame retardance in PP was studied by measuring the limiting oxygen index and water resistance.Compared with APP,the solubility of MFAPP prepared in water-alcohol mixed solvent decreased sharply,and the appearance of melamine function group was observed through FT-IR analysis.With the increase of the ratio of water and ethanol,the content of melamine-formaldehyde resin in MFAPP increased.When the volume ratio of water and alcohol is about 1:1,the microencapsulation and water resistance of MFAPP were the best.With w=30% MFAPP in PP,the LOI value of PP/MFAPP was as high as 29.5%.