微胶囊次磷酸铝的制备及在TPU/WPU中的应用

Preparation of Microencapsulated Aluminum Hypophosphite and Its Application in TPU/WPU

采用多羟甲基三聚氰胺自聚物为囊材,无机次磷酸盐为芯材,制备了多羟甲基三聚氰胺次磷酸盐微胶囊。通过傅里叶变换红外光谱(FTIR)仪、扫描电子显微镜(SEM)和热重分析对材料进行了表征,结果表明:微胶囊材料FTIR光谱中存在次磷酸盐和多羟甲基三聚氰胺的特征峰,说明次磷酸盐被多羟甲基三聚氰胺成功包覆;SEM图片可以看到次磷酸盐表面均匀覆盖一层致密层,说明次磷酸盐分子结构表面被完全包覆;与次磷酸盐相比,微胶囊材料的最大分解温度从338.9℃提高到351.12℃,热失重速率温度明显提高,燃烧后的残炭量增加5%,说明增强了微胶囊材料的热稳定和阻燃效果。微胶囊次磷酸铝阻燃剂可替代次磷酸铝应用到热塑性聚氨酯和水性聚氨酯材料中,并辅以磷氮协效体系,既提高了阻燃性能,又保证了基材的物理特性,拓宽了应用范围。

The polyhydroxymethyl melamine hypophosphate microcapsules were prepared by using polyhydroxymethyl melamine self-polymer as the capsule material and inorganic hypophosphates as the core material.The microcapsules were characterized by Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM) and thermogravimetric analysis.The results show that there are characteristic peaks of hypophosphite and polyhydroxymethyl melamine in the FTIR spectra,the results show that the surface of hypophosphite is covered by polyhydroxymethyl melamine.SEM show that the surface of hypophosphite is covered by a dense layer,which indicates that the molecular structure of hypophosphite is completely covered.The maximum decomposition temperature of the microcapsule material is increased from 338.9°C to 351.12°C,the temperature of the thermal weightlessness rate is obviously increased,the amount of residual carbon after combustion is increased by 5%,which indicate that the thermal stability and flame retardant effect of the microcapsule material are enhanced.Microencapsulated aluminum hypophosphite can be used in thermoplastic polyurethane and waterborne polyurethane materials instead of aluminum hypophosphite,the synergistic system of phosphorus and nitrogen can not only improve the flame retardancy,but also ensure the physical properties of the substrate and broaden the application range.