Comparative Study of Kraft Paper Aged in Natural Ester with XRD and TG/DTG Analysis

High voltage transformer is an essential power apparatus that determine the reliability and continuity of power transmission and distribution system. It comprises solid and liquid insulating materials. Kraft paper as solid insulation should have an ability to insulate the winding connection, while oil transformer, aside of its main function as insulation, it is also used as a coolant. This paper analyzes the accelerated thermal aging performance of kraft paper immersed in the natural ester from RBD palm oil by using X-Ray Diffraction (XRD) characterization. XRD characterization was used to determine the existence of crystalline structure in kraft paper. Crystalline structure in kraft paper is composed by cellulose. The toughness of kraft paper was determined by its amorphous region, lignin, that bind the cellulose and make them hard. The influence of thermal expansion was observed to discover the effect of thermal stress to the crystallinity of kraft paper. Besides, thermal degradation characteristics of kraft paper were examined by using thermogravimetric analysis. The sample was aged in 120°C and 150°C for two weeks. The results also show that crystalline region of the sample that heated in higher aging temperature tends to drop faster than the sample with lower aging temperature.