Abstract A novel boron-containing chain extender of diglyceride borate was synthesized and used to improve flame retardancy of polyurethane (PU). Diglyceride borate derived from boric acid with glycerin was synthesized by esterification reaction. The boron-containing polyurethanes were synthesized from polyether polyol, 4,4-diphenylmethane diisocyanate (MDI) and diglyceride borate through one-step method. The structure of diglyceride borate was fully characterized by Fourier transform infrared spectroscopy (FTIR), 1H-NMR. The thermal stability and fire behaviors of boron-containing PU were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL-94 rating and cone calorimeter (CCT). The LOI increased from 23.8% to 30.0%, with the content of diglyceride borate in the polymer chains increased from 13.6% to 25.7%, meanwhile char formation was enhanced and heat release reduced. Scanning electron microscope (SEM) images, residue digital photos, FTIR, Raman spectroscopy and X-ray diffraction (XRD) analysis of the char residues suggested the formation continuous compact char layer. The results showed that the flame retardancy of polyurethane was positively correlated with boron content.

中文翻译：

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新型含硼聚氨酯的合成及阻燃性能

摘要 合成了一种新型含硼硼酸甘油酯扩链剂，用于提高聚氨酯（PU）的阻燃性。通过酯化反应合成由硼酸与甘油衍生的硼酸甘油二酯。含硼聚氨酯由聚醚多元醇、4,4-二苯基甲烷二异氰酸酯（MDI）和硼酸甘油二酯一步法合成。硼酸甘油二酯的结构通过傅里叶变换红外光谱（FTIR）、1H-NMR 进行了充分表征。通过热重分析(TGA)、极限氧指数(LOI)、UL-94等级和锥形量热仪(CCT)研究了含硼PU的热稳定性和防火性能。LOI从23.8%提高到30.0%，聚合物链中硼酸甘油二酯的含量从13.6%提高到25.7%，同时，炭的形成增强，放热减少。炭残余物的扫描电子显微镜 (SEM) 图像、残余物数码照片、FTIR、拉曼光谱和 X 射线衍射 (XRD) 分析表明形成了连续致密的炭层。结果表明，聚氨酯的阻燃性与硼含量呈正相关。