Polyester and Polyesterimide Compounds with Nanofillers for Impregnating of Electrical Motors

Polyester and polyesterimide compounds for impregnating of electrical motors were modified by incorporating of three kinds of nanofillers: zinc oxide, fumed nanosilica and titanium dioxide so as to improve their properties. Nanosized particles were added at 1 wt.% of loading and homogeneously dispersed in polyester and polyesterimide matrix. The results on mechanical, electrical and barrier properties of standard and nanofilled compounds were compared. Thermogravimetric/differential thermal analysis showed that thermal stability of nanofilled compounds was significantly higher. Also the electrical and bonding strength of nanofilled impregnating compounds increased and at the same time water absorption decreased. The highest improvement of properties owing to nanofillers was obtained in the case of nanosilica.