Molecular Simulation on Dielectric and Mechanical Properties of Epoxy-Polyether amine Resin

The epoxy resin has been widely used in power equipment, e.g. bushing, GIL/GIS insulator, whose performance affects the safety and stability operation of power system indirectly. However, epoxy resin usually become brittle after curing, making it easy to craze and breakdown. Selecting curing agents with flexible chains such as polyether amine is possible to toughening epoxy resin. In this paper, a series of epoxy-polyether amine crosslinking model are built based on molecular dynamics simulation. The mean molecular weight of polyether amine is 230 and 400 g/mol respectively. The T g is calculated by temperature dependence of mean square displacement instead of density, because the change of density is two slight to find out the inflection point. Calculated T g of ER-D230 and ER-D400 is 380.0 K and 349.9 K The dielectric constant and mechanical properties are respectively obtained from the dipole moment fluctuation and constant strain method. At 290K, the dielectric constant of ER-D400 is higher than that of ER-D230, but ER-D230 is more flexible. Long and flexible chain of hardener provide more space to vibration, rotation and move for chain segments and more motion of polar group is excited above T g, leading to higher dielectric constant and lower mechanical modulus.