硼酸钙2CaO·5B2O3·5H2O纳米材料的水热制备及其阻燃性能的热化学策略评价

Hydrothermal preparation of 2CaO·5B2O3·5H2O nanomaterials and evaluation of their flame retardant properties by thermochemical strategies

硼酸盐阻燃剂已应用于纤维、树脂、橡胶及木材等方面的阻燃.如何解决制备颗粒大而阻燃效果不佳的问题已成为新型硼系阻燃剂研究和应用的瓶颈之一。本文采用水热法,通过调控溶液pH和水热反应温度,可控制备了2CaO·5B2O3·5H2O纳米盘和微纳米片,并通过XRD、FTIR、TGA、FESEM和TEM等手段对样品进行了表征。采用多种热化学策略(包括TGA、DSC和非等温热分解动力学方法)对制备的2CaO·5B2O3·5H2O纳米材料对松木粉的阻燃性能进行了研究,并通过氧指数法进行了验证并且提出了阻燃机理.结果表明,添加10%2CaO·5B2O3·5H2O纳米盘的松木粉试样TG失重少、DSC放热量少、热分解反应活化能Ea大并且氧指数LOI值大,具有比2CaO·5B2O3·5H2O微纳米片更好的阻燃性能.通过横向比较表明, 2CaO·5B2O3·5H2O纳米盘的阻燃性能比2CaO·B2O3·H2O纳米片的阻燃性能更好,结合2CaO·5B2O3·5H2O纳米盘制备方法简单和水热反应温度低,预估2CaO·5B2O3·5H2O纳米盘可以作为一种潜在的实用型阻燃剂。

Borate is a kind of green and environmental protective flame-retardant, which has been used in fiber, resin and wood and the like. To solve this bottleneck problem of prepared larger particles for borate flame-retardant which makes its poor flame retardant in the research and application, we prepared the calcium borate 2CaO·5B2O3·5H2O nanoplate and micro/nanosheet under hydrothermal conditions by adjusting pH of solution and reaction temperature,which were characterized by the XRD, FTIR, TGA, FESEM and TEM. The flame retardant properties of the prepared2CaO·5B2O3·5H2O samples were investigated by using multiple thermochemical strategies(including TGA, DSC and non-isothermal decomposition kinetics), and further verified by limited oxygen index method. The nanoplate sample has the less TG mass loss and heat release for DSC, as well as the bigger LOI value, and apparent activation energy Ea.These show that the flame retardant property of prepared 2CaO·5B2O3·5H2O nanoplate sample is stronger than that of micro/nanosheet sample. The possible flame retarding mechanism has been proposed. In addition, the horizontal comparison shows that the flame retardant property of prepared 2CaO·5B2O3·5H2O nanoplate is also better than that of2 CaO·B2 O3·H2 O nanosheet. This research indicated that 2CaO·5B2O3·5H2O nanoplate could be a potential utility-type flame retardant.