Microencapsulation Ammonium Polyphosphate's Preparation And Application In Polypropylene

Due to low smoke, innocuity, no caustic gas and second pollution producing, intumescent flame retardant exceeds halogen-containing flame retardants and inorganic flame retardant. Therefore, intumescent flame retardant technology is known as a revolutionary of flame retardant technology, and becomes the most active research field of the flame retardant in recent years. But because of the hygroscopicity and compatibility, the intumescent flame retardant's application is limited. In this paper in order to promote the application of intumescent flame retardant, the following works are done.1. Microencapsulation ammonium polyphosphate (MAPP) that has excellent water resistance was prepared by melamine formaldehyde resin (MF) capsuled ammonium polyphosphate (APP) in water. Its water resistance was increased as the proportion of capsule material increased, when MF/APP=1/3, its solubility at 50℃was 0.052g, reduced 78%than that of APP. MAPP was a intumescent flame retardant, when MF/APP=1/3, its intumescent degree and char yield of MAPP at 400℃was 78.6cm3/g and 61.96%respectively, and the flame retardance of PP/MAPP was the best. The thermal analysis indicated that the degradation of PP/MAPP was more rapidly but its heat release reduced greatly compared to that of PP/APP.2. The use MAPP and PA6 together can improve the flame retardance of PP. The test indicated that the intumescent degree and char yield of MAPP/PA6 increased than that of MAPP. when PP/MAPP/EPP/PA6=75/25/7/3, its oxygen index was 34.7, and the mechanical strength was 28.89 Mpa, which increased 0.3 times and 0.17 times than that of PP/MAPP respectively. The thermal analysis indicated that adding PA6 was advantageous to increase flame retardance of PP at low temperature zone, however, at high temperature zone, it release more heat that was unadvantageous to increase flame retardance of PP. So the charge of PA6 should be appropriate.3. The alkyl silicone oil can improve compatibility of PP/MAPP composites. when PP/MAPP/silicone oil-600=75/25/0.25,The mechanical strength was 19.71 MPa, which increased 0.74 times than 11.33 Mpa of PP/MAPP. SEM and POM showed that silicone oil- 600 improved compatibility of PP/MAPP; Torque indicated that silicone oil-600 was true lubricants of PP/MAPP. XRD showed that MAPP hasβnucleation for PP, and silicone oil-600 strengthened theβ-nucleation of MAPP.