Study On Intumescent Flame Retardant System For Polyolefin

Polyolefin is the polymer material was used most, but their flammability is a grievous menace to our lives and properties. Considering the request of protecting environment, the usage of halogen flame retardants was limited in the polyolefin and the intumescent flame retardant is springing up. The thesis studied the several improvement methods of intumescent flame retardant for polyolefin. It consists of four parts.In the first chapter, the type, effect and development of flame-retardants on polyolefin were reviewed, as well as the recent studies on the intumescent flame retardant. The purpose, significance and result in this paper were also summarized.In the second chapter, the role of metal oxides in ammonium polyphosphate-based intumescent flame retarded polypropylene was studied the by limiting oxygen index, thermal analysis and inferred spectrum et al. The data showed that the flame-retardance, the thermal stability and mechanical property of PP blends have been improved compared after the metal oxides were added.In the third chapter, the synergistic effect of expandable graphite with Ammonium polyphosphate in the polyethylene has been studied. The results show that EG and APP can affect each other in the combustion and product better char configuration. Therefore EG can cooperate with APP well. Moreover the mechanical property of the HDPE blends is nicer.In the fourth chapter, microencapsulated polyphosphate ammonium was prepared with melamine resin as the shell by in-situ polymerization and applied to the PP. The flame-retardance and the thermal stability of PP blends have been improved compared with the untreated.