Study On Nylon6Modified By Phosphorous Hyperbranched Polyamide

Hyperbranched polymers have high degree of branching, low chain entanglement, a large number of end functional groups and other structural features, so they own low viscosity. high reactivity, good solubility, the end groups which can be further functionalized and so on. Phosphorous hyperbranched polyamide(P-HBPA) as a hyperbranched polymer, not only has the properties of hyperbranched polymers, but also has the excellent performance of aromatic polyamide, such as heat-resistance and fire-resistance. At the same time, P-HBPA has flame retardant due to its phosphorus structure, thus P-HBPA is a good modifier, and may be used in plastic modification.In this paper, three (3-the nitro phenyl) phosphine oxide(TNPPO) was first prepared from three phenyl phosphine oxide by using mixed acid nitration method, the yield was93.3%, then three (3-the amino phenyl) phosphine oxide(TAPPO) was synthesized by TNPPO with the hydrazine hydrate, the yield was71.1%; and then using solution polymerization, TAPPO and isophthaloyl chloride(lPC) as the monomers, P-HBPA was synthesized by with the A2+B3method. The effects of reaction conditions, such as the monomers ratio, the reaction time and temperature, on the polymerzation had been investigated systemically. The experimental results showed the best conditions for the synthesis reaction: A2(the molar ratio of isophthaloyl chloride) and B3(three (3-amino phenyl) phosphine oxide) was2:3, the reaction temperature (dissolving and feeding) was25℃, IPC was added in batches, the reaction concentration was0.10mol/L, heated to50℃, the reaction time was2h. Its structure was characterized by fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(1H NMR), the degree of branching(DB) of P-HBPA was determined by1H NMR and DB was0.36, the viscosity and solubility of P-HBPA were tested.And then blend nylon6(PA6) with P-HBPA to produce the blends of PA6/P-HBPA. The effects of P-HBPA content on the PA6/P-HBPA blends were investigated. The mechanical properties, the crystallization, dynamic properties, and flame resistance as well as notched impact fracture surface of the blends were studied via mechanical testing machines, differential scanning calorimetry(DSC), dynamic mechanical analyzer(DMA), oxygen index detector, and scanning electron microscope(SEM), respectively. It was found that the tensile strength, the impact strength and the flexural strength of PA6/P-HBPA blends were increased respectively by8.79%,11.53%and6.72%, with P-HBPA loadings of0.5%; and the LOI value increased from25to28, with P-HBPA loadings of1.5%.