Study On The Preparation And Properties Of Halogen-free Flameretardant Pet

Flame retardant of polyethylene terephthalate(PET) is a ver y important engineering plastic. PET has good dimensional stability, thermal and arc-tracking resistance. It is resistant to oil, greases and cleaning fluid. With its high strength, chemical resistance, spinnability and thermal stability, polyethylene terephthalate is a widely used material in the automotive industry, food and beverage packaging, as well as in synthefic fibers for textiles. It can be used in manufacture of electronic components, which require thermal stability, chemical resistance, electrical insulation, highmechanical strength and anti-friction. In this paper, two kinds of halogen-free flame retardant PET material were prepared by using aluminum diethylphosphinate(ADP), melamine cyanurate(MCA) and composite phosphonate. The physical and flame retardant properties of the fla me retardant PET were characterized and falme retardant mechanism were also investigated.A series of flame retardant PET materials which have different amount of flame retardant additive were prepared by using alumiun diethylphosphinate(ADP), melamine cyanurate(MCA)and composite phosphonate. The thermal stability of flame retardant and flame retardant PET materials were characterized by TGA. The thermal degradation kinetics of activation energy of flame retardant PET materials were calculated through the different TGA heating rates; the flame retardant PET materials ’ crystallization properties which are influenced by flame retardants were characterized by DSC and polarizing microscope; Rheological properties were characterized by using rheometer; The fracture surface of flame retardant PET materials were characterized by SEM. It was found that the flame retardant could maintain good stability in the preparation of falme retardant PET materials. It also had good compatibility with PET resin, which make flame retardant PET materials have good thermal stability,crystallinity,processability and char-forming.Using limiting oxygen index(LOI) and vertical burning text(UL-94) to characterize the combustion behavior of PET composites materials. The results of the study show that when the content of aluminum diethylphosphinate/melamine cyanurateis is 10% and anti-dripping agent is 0.5%, the LOI value of the composites is 31.3% and the UL-94 rating reaches to V-0; when the content of composite phosphosphonate is 8%, the LOI value of flame retardant PET marterials is 31.6% and the UL-94 rating reaches V-0. In addition, the possible flame retardant mechanism related to carbon layer structure and the constituent of char residue after combustion texts, characterized by FT-IR, SEM and EDS. The resulted showed both two flame retardants promote PET composites to generate a dense carbon layer in the condensed phase, which cut off the transferring of heat and oxygen to prevent further burning.