盆式绝缘子用环氧/氧化铝复合体系固化动力学

Curing Kinetics of Epoxy/Alumina Composite System for Basin Insulator

环氧树脂/氧化铝复合体系的配方组成、理化特性及固化工艺对特高压大尺寸盆式绝缘子的质量有重大影响。为此应用非等温差示扫描量热(DSC)法,研究了不同固化剂含量的环氧树脂/氧化铝复合体系固化反应过程。随着固化剂含量增加,DSC曲线由双峰转变为单峰。所有试样前段固化的表观活化能(Ea)基本不变,低固化剂含量试样后段固化的Ea随固化剂含量增大显著减小。结果表明,固化催化反应控制在前段固化中占主导地位,而扩散控制和反应控制在后段固化中具有竞争作用。实际固化过程符合SB(m, n)模型,自催化反应在固化反应中起主导作用。

The formulation composition,physicochemical properties and curing process of the epoxy resin/alumina composites system remarkably affect the quality of UHV large-sized basin insulations.Consequently,we employed the non-isothermal differential scanning calorimetry method to study the curing reaction process of epoxy resin/alumina composites containing different curing agent contents.A two-peak curve of DSC would change to a single-peak curve as the content of the curing agent increased.The apparent activation energy(Ea)of pre-stage curing of all samples was essentially unchanged.The Ea of post-stage curing with low curing agent content would decrease significantly as the content of the curing agent increased.The results show that the curing catalytic reaction control dominates in the pre-stage curing process,while the diffusion control and the reaction control have competitive effects in the post-stage curing.The actual curing process accords with the SB(m,n)model,indicating that the autocatalytic reaction plays a leading role in the curing process.