含磷/氮/硫环交联磷腈微纳米管的合成及对环氧树脂的阻燃作用

采用原位模板法,以六氯环三磷腈(HCCP)和二羟基二苯砜(BPS)为原料合成了一种环状交联型不溶不熔的磷腈大分子——聚环三磷腈-二羟基二苯砜(PZS)微纳米管,研究了PZS对环氧树脂(EP)的阻燃作用及阻燃机理.利用红外光谱(FTIR)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)对PZS微纳米管进行了表征;采用热重分析(TG)考察了EP/PZS阻燃材料的热稳定性,并通过极限氧指数(LOI)和微型量热分析(MCC)测试了EP/PZS的阻燃性能.热降解实验结果表明,PZS微纳米管的加入使环氧树脂热降解温度降低,但残炭率显著提高.PZS微纳米管可以显著提高环氧树脂的阻燃性能,当阻燃剂添加量为5%时,环氧树脂的残炭率提高了46%,热释放速率峰值降低了约40%;LOI值从纯环氧树脂的26.0%提高到了30.6%.PZS微纳米管的加入还增强了环氧树脂的力学强度.阻燃性能的显著提高和力学性能的改善归因于PZS微纳米管在环氧树脂基体中的良好分散,以及燃烧炭化过程中生成的石墨化程度较高的类石墨烯结构的残炭,具有较高的抗氧化能力.研究结果表明,PZS微纳米管是一种优良、高效的具有潜在应用价值的阻燃剂.

Synthesis of a Phosphorus/Nitrogen/Sulphur Containing Phosphazene Micro-Nanotube and Its Flame Retardancy on Epoxy Nanocomposite

A highly cross-linked poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol)(PZS) nanotubes were synthesized via an in situ template method using cyclotriphosphazene ( HCCP ) and 4, 4′-sulfonyldiphenol (BPS) as raw materials. PZS micro-nanotubes were applied on epoxy resin ( EP) and the flame retarded mechanism was studied. The PZS micro-nanotubes were characterized by SEM, TEM, EDS and element Map-ping. The thermalstability of PZS / EP nanocomposites were explored through TG, as compared to that of EP, and the flammability was investigated by microscale combustion calorimeter( MCC) and limit oxygen index (LOI) tests. The TGA results showed that a decreased initial degradation temperature, the residue chars were greatly improved. The flame retardancy was significantly enhanced by the addition of PZS micro-nanotubes. The residue char was improved 46% and the heat release rate was reduced 40% under addition of PZS micro-nanotubes(5%). The LOI value was also improved from 26.0% to 30. 6%. The mechanical strength was also improved by the addition of PZS micro-nanotubes. The improvement of flame retardancy can be ascribed to the good dispersion and the formation of graphene-like structure during combustion of PZS / EP nanocomposites. In conclusion, PZS micro-nanotube is a kind of excellent flame retardant with potential application value.