纳米Sb_2O_3与次膦酸铝阻燃聚对苯二甲酸乙二醇酯协同作用研究

SYNERGISTIC EFFECT OF NANO-Sb_2O_3 AND ALUMINIUM PHOSPHINATE ON FLAME RETARDANCY OF PET

制备了浓度为80%的纳米三氧化二锑母粒(M-nano-Sb2O3),以此母粒与二乙基次膦酸铝(AlPi)复合阻燃聚对苯二甲酸乙二醇酯(PET).氧指数、UL 94垂直燃烧、锥形量热仪及扫描电镜研究表明,nano-Sb2O3和AlPi之间的协同阻燃作用导致PET的氧指数由21.0%提高到了34.6%,UL 94垂直燃烧达到V-0级,热释放速率(HRR)、总烟释放(TSR)和CO释放量均有所降低,炭层的致密性显著变好.热失重、傅里叶变换红外光谱及X射线光电子能谱分析指出,协同作用增加了阻燃PET的残炭量及热稳定性,nano-Sb2O3表面的羟基与二乙基次膦酸发生缩合反应促进了成炭,残炭结构主要由磷酸铝(锑)、焦磷酸酸铝(锑)和共轭芳香环状物组成.差示扫描量热研究显示,协同作用有利于促进阻燃PET的结晶及增加熔融吸热量.因此,nano-Sb2O3与AlPi协同阻燃PET是以凝聚相交联成炭及吸热作用为主,兼有气相阻燃作用.

A nano-Sb2O3masterbatch（ M-nano-Sb2O3） whose concentration was 80% was prepared. The masterbatch was added into poly（ ethylene terephthalate） synchronized with aluminium diethlyphosphinate（ AlPi）. Different test methods such as limiting oxygen index（ LOI）,vertical burning（ UL 94）,cone calorimeter（ CONE）,scanning electron microscope（ SEM） demonstrated that the LOI of PET increased from21. 0% to 34. 6% and the UL 94 vertical burning rating reached V-0; the heat release rate,total smoke release and CO production were reduced; the compact degree of the char residue was remarkably improved. All these phenomena were due to the synergism between nano-Sb2O3and AlPi. Morever,thermal gravimetric analysis（ TGA）,X-ray photoelectron spectroscopy（ XPS） and Fourier transformed infrared spectroscopy（ FTIR）pointed that the synergistic effect increased the char residue and its thermal stability,the char formation was promoted by the condensation of diethylphosphinic acid with the Sb-OH on the surface of nano-Sb2O3,and the char residue was mainly consisted of aluminum（ antimony） phosphates,aluminum（ antimony） pyrophosphate and organic compounds containing aryl cyclic structure. Differential scanning calorimetry（ DSC） showed that the synergistic effect facilitated the crystallization of PET and its melting endotherm. Therefore,flame retardancy mechanisms in PET for AlPi in combination with nano-Sb2O3were primarily cross-linking reactions,char formation in condensed phase and endothermic effect,meanwhile,gas phase mechanism was also involved.