MgAlZnFe-CO3 LDHs对PBS膨胀阻燃体系性能的影响

采用恒定pH值共沉淀法在自制反应器中合成了不同原料配比的碳酸根型镁铝锌铁层状双羟基金属氧化物（MgAlZnFe-CO₃ LDHs），并通过熔融共混MgAlZnFe-CO₃ LDHs、聚磷酸铵（APP）、三聚氰胺（MA）和全降解材料聚丁二酸丁二醇酯（PBS）制备出PBS膨胀阻燃材料. 采用傅里叶红外光谱（FTIR）、热失重（TG）、X射线衍射（XRD）、扫描电子显微镜（SEM）及元素分析（ICP）对MgAlZnFe-CO₃ LDHs进行了表征，并对PBS膨胀体系进行了力学性能和阻燃性能等测试. 结果表明，当Mg²⁺，Zn²⁺，Al³⁺和Fe³⁺的摩尔比为9：3：3：1时，合成的MgAlZnFe-CO₃ LDHs热稳定性最好，晶态结构规整，呈形貌规则的六边形片状；当MgAlZnFe-CO₃ LDHs的添加质量分数为1%时（阻燃剂的总添加质量分数为20%）时，PBS膨胀阻燃体系的极限氧指数（LOI）达到35%，垂直燃烧测试达到UL-94 V-0级别，力学性能得到较大改善. 实验结果表明，低添加量的MgAlZnFe-CO₃ LDHs与膨胀阻燃剂（IFR）协效阻燃PBS，一方面能够改善膨胀阻燃剂恶化PBS力学性能的现象，另一方面协同效应能够明显提高PBS的阻燃性能.

Effect of MgAlZnFe-CO3 LDHs on Fire Retardancy and Mechanical Properties of Intumescent Flame Retardant Poly(butylene succinate) Composites

MgAlZnFe-CO₃ layered double hydroxides(LDHs) with different proportions of metal ions were prepared by the constant pH coprecipitation method. Ammonium polyphosphate(APP), melamine(MA), and MgAlZnFe-CO₃ LDHs were added in poly(butylene succinate) via melt blending to obtain the novel intumescent flame retardant poly(butylene succinate)(IFR-PBS) composites with MgAlZnFe-CO₃ LDHs as a synergistic agent. The synthesized MgAlZnFe-CO₃ LDHs were characterized by X-ray diffraction(XRD), Inductive coupled phasmamass spectrometer(ICP) and scanning electron microscope(SEM). Consequently, the layered structures of the synthesized MgAlZnFe-CO₃ LDHs were observed. The fire retardancy and mechanical properties of the novel IFR-PBS composites were also evaluated. Compared to those of IFR-PBS composites without MgAlZnFe-CO₃ LDHs, the limiting oxygen index(LOI) values of the novel IFR-PBS composites increased from 30% to 35% and the vertical flammability(UL-94) reached V-0 rate when the content of MgAlZnFe-CO₃ LDHs was 1%(the total loading of flame retardant was 20%). Importantly, the tensile strength and flexural strength of the novel IFR-PBS composites could be enhanced by the presence of MgAlZnFe-CO₃ LDHs.