Study On Preparation And Performance Of Flame Retardant PA6

Nylon materials are widely used in construction, transportation, electronics, aerospace and other fields. In the research process of flame-retardant nylon6, halogen and phosphorus flame retardant were first widely used because of its high effect and lower content. However, for the comprehensive consideration of environmental protection, human health and flame-retardant efficiency, the development of halogen free and phosphorus free flame-retardant nylon6is imminent and conform to the technology trend. Therefore, nano-magnesium hydroxide (NMH), melamine cyanurate (MCA) and ammonium polyphosphate (APP) were selected to composite for environmental flame retardant PA6in this thesis; The performance of PA6composite materials under different processing conditions were studied; Through the theoretical calculation, the relationship between the content of magnesium hydroxide and flame retardancy of nylon6was verified, the relationship between the dispersion of magnesium hydroxide and flame retardancy of nylon6was analysed, the critical mass fraction of magnesium hydroxide in flame retardant nylon6was calculated.Main research contents and results:1) NMH/PA6flame retardant materials were prepared. The combustion rate of the materials were decreased while the content of NMH were increased. NMH modified by titanate coupling agent can improve the flame retardancy of the composites. Increase the number of melting times of NMH/PA6compound materials, NMH particle was distributed gradually, density were decreased slightly and the melting point of compound materials were increased;2) The grafting PE with maleic anhydride (PE-g-MAH) was prepared by Φ20twin screw extruder under140～160℃and used as compatibilizer for NMH/PA6system. Orthogonal experiments analysis showed that preferred plan of PE-g-MAH was0.06wt.%BPO,0.10wt.%AA,4wt.%MAH and0.45wt.%DCP. PE-g-MAH can greatly increase the flame retardancy and mechanical properties of the composite when the addition of PE-g-MAH is2wt.%. 3) Added NMH to nitrogen-phosphorus flame retardant system to prepare flame retardant PA6can get a good flame retardant PA6. When coupling agent was1.5wt.%, MCA was7.5wt.%, NMH was12.5wt.%and APP was5.0wt.%, good comprehensive property of flame retardant PA6material was obtained.i.e.the burning distance was Omm, the tensile strength was40.24MPa, the melt index was5.43g/lOmin, and the Rockwell hardness was80.67;4) Flame retardancy of NMH/PA6composite materials can be analyzed by "flame-retardant effect of spherical packing model". The results showed that the flame retardant performance of PA6was improve while the amount of NMH was increased or the dispersion of NMH uniformed; The critical mass fraction of NMH of NMH/PA6intrinsic flame retardant material was26.88wt%.