喷雾干燥工艺制备含氟弹性体包覆超细NTO复合微粒及其性能表征

Preparation and characterization of fluoroelastomer-coated ultrafine NTO composite particles by spray drying process

为了研究包覆含氟弹性体后NTO(3-硝基-1,2,4-三唑-5-酮)性能的变化,选取了6种常用的含氟弹性体:F_(2602)、F_(2604)、F_(2461)、F_(2463)、F_(2311)和F_(2314),并采用喷雾干燥工艺制备了细化NTO/含氟弹性体包覆粒子(其中含氟弹性体质量分数为3.5%和5%);分别采用扫描电镜(SEM)、纳米粒度和Zeta电位分析仪对样品形貌粒度进行了表征;并采用X射线晶体衍射(XRD)、X射线光电子能谱(XPS)和红外光谱(FT-IR)对样品结构进行了表征;采用差示扫描量热法(DSC)对样品热性能进行了分析。结果表明:细化NTO/含氟弹性体为粒径260~660 nm的块状或棒状颗粒;包覆后NTO的晶型未发生改变,仍为α-NTO;与其他细化NTO/含氟弹性体相比,NTO/F_(2314)有较好的热稳定性,NTO/F_(2314)-3.5%的热爆炸临界温度与活化能均值相比于细化NTO分别提高了5.8 K和18.27 kJ·mol^(-1)。喷雾干燥工艺的应用避免了传统的水悬浮包覆工艺中对NTO的较大浪费,而多种细化NTO/含氟弹性体包覆粒子的制备为未来对NTO的改性研究打下了良好基础。

In order to study the performance changes of NTO(3-nitro-1,2,4-triazol-5-one)coated with fluoroelastomer.Six commonly used fluoroelastomers were selected:F_(2602),F_(2604),F_(2461),F_(2463),F_(2311),F_(2314).Refined NTO/fluoroelastomer coated particles were prepared by spray drying process(the mass ratio of refined NTO:fluoroelastomer was 3.5%and 5%).The morphology and particle size of the samples were characterized by SEM and nanoparticle size and Zeta potential analyzer.The components of samples were characterized by XRD,XPS and FT-IR.The thermal properties of the samples were analyzed by DSC.The results show that the refined NTO/fluoroelastomer is in the form of massive or rod-shaped particles of 260~660 nm.After coating,the crystal form of NTO was unchanged and remains theα-NTO crystal.3.5%of FF_(2314) was coated on the NTO to form NTO/F_(2314),which makes the thermal explosion critical temperature and activation energy of refined NTO have a mean value of 5.8 K and 18.27 kJ·mol^(-1) increase.The application of the spray drying process avoids the large waste of NTO in the traditional water suspension coating process.The preparation of a variety of refined NTO/fluoroelastomer coated particles lays a good foundation for future research on NTO modification and provides a direction for heat-resistant modification.