Study On The Flame Retardant Properties Of Short Glass Fiber Reinforced Nylon 6 By Ammonium Polyphosphate With High Polymerization Degree

In this paper, ammonium phosphate (APP) with the high polymerization degree was used as the main flame retardant, and combined with other synergistic agent to flame retard short glass fiber (SGF) reinforced polyamide 6 (PA6) material. The main contents are shown as follows:The APP/pentaerythritol (PER)/melamine (MEL) intumescent flame retardant system was used as flame retardant, while short glass fiber were treated by MEL. APP/PER/MEI/SGF/PA6 and APP/PER/MEL-SGF/PA6 composites were prepared. The effects of addition way and content of APP/PER/MEI on the flame retardant properties and mechanical properties of the PA6/SGF composites were studied by Fourier transfer infrared (FT-IR) spectroscopy, Limiting oxygen index (LOI), UL-94 test, cone calorimeter test (CCT), scanning electron microscopy (SEM) and mechanical properties measurements. The results show that, when the amount of APP/PER/MEL is 25 wt%, which can make 35 wt% short glass fiber reinforced PA6/SGF composites achieve UL-94 V-0 rating. Moreover, the resulting flame retarded composites possess excellent mechanical properties. With the same level of the UL-94 test, APP/PER/MEL-SGF/PA6 composite has higher LOI value, lower total heat release (THR), heat release rate (HRR) and mass loss, and longer ignition (TTI) compared with APP/PER/MEL/SGF/PA6 composite. On the basis of the above analyses, the flame retardant mechanism was also studied by thermogravimetric analysis (TGA).The phenol formaldehyde resin (PF) was modified by poly phosphoric acid (PPA) and used as the carbon source, which was compound with APP and MEL to construct expansive flame retardant. APP/PPA-PF/MEL/SGF/PA6 composites were prepared, while APP/PF/MEL/SGF/PA6 composites were prepared for comparison. The flame retardant properties and mechanical properties of PA6/SGF composites were studied by FT-IR、 LOI、 UL-94、 CCT、 SEM、 tensile and impact measurements. The results show that,25 wt% APP/PPA-PF/MEL(1/0.25/0.18) can make 35 wt% short glass fiber reinforced PA6/SGF composites achieve UL-94 V-0 rating, and the flame retardant properties and mechanical properties of APP/PPA-PF/MEL/SGF/PA6 composites are superior to those of APP/PF/MEL/SGF/PA6 composites. On the basis of the above analyses, the flame retardant mechanism was also studied by thermogravimetric analysis (TGA).The basic magnesium sulfate whisker (MOS) was compounded with APP as flame retardant and a series of APP/MOS/SGF/PA6 composites with different MOS content were prepared. The flame retardant properties and mechanical properties of APP/MOS/SGF/PA6 composites were studied by FT-IR、LOI、 UL-94、 CCT、 SEM、 tensile and impact tests. The results show that,25 wt% APP/MOS(85/15) flame retardant can make 35 wt% short glass fiber reinforced PA6/SGF composites achieve UL-94 V-0 rating, which also possesses excellent mechanical properties. On this basis, the flame retardant mechanism of the flame retardant system was also studied by TGA analysis.