Mohamad Nur Aqilah, Azis Norhafiz, Jasni Jasronita, Ab Kadir Mohd Zainal Abidin, Yunus Robiah, Yaakub Zaini
Centre for Electromagnetic and Lightning Protection Research (CELP), Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Materials (Basel). 2018 Mar 30;11(4):532. doi: 10.3390/ma11040532.
This paper presents a sealed ageing study of palm oil (PO) and coconut oil (CO) in the presence of insulation paper. The type of PO under study is refined, bleached, and deodorized palm oil (RBDPO) olein. Three different variations of RBDPO and one sample of CO are aged at temperatures of 90 °C, 110 °C, and 130 °C. The properties of RBDPO and CO as well as paper under ageing are then analysed through dielectric and physicochemical measurements. It is found that the effect of ageing is not significant on the alternating current (AC) breakdown voltages and relative permittivities of RBDPO and CO. There is a slight increment trend of the resistivity for CO, while for all of the RBDPO, the resistivity slightly decreases as the ageing progresses. Only CO shows an apparent reduction of the dielectric dissipation factor. Throughout the ageing time, the acidities of all of the RBDPO and CO remain at low level, while the moisture in oils decreases. The tensile index (TI) of the papers for all of the RBDPO and CO retain more than 50% of the TI. A significant increment of the paper ageing rates of all of the RBDPO and CO is observed at an ageing temperature of 130 °C.
本文介绍了在绝缘纸存在的情况下对棕榈油（PO）和椰子油（CO）进行的密封老化研究。所研究的PO类型为精炼、漂白和除臭棕榈油（RBDPO）油酸。三种不同变体的RBDPO和一个CO样品在90°C、110°C和130°C的温度下老化。然后通过介电和物理化学测量分析老化过程中RBDPO和CO以及纸张的性能。结果发现，老化对RBDPO和CO的交流（AC）击穿电压和相对介电常数影响不显著。CO的电阻率有轻微上升趋势，而对于所有RBDPO，随着老化的进行，电阻率略有下降。只有CO的介电损耗因数明显降低。在整个老化时间内，所有RBDPO和CO的酸度保持在较低水平，而油中的水分减少。所有RBDPO和CO的纸张拉伸指数（TI）保留率超过50%。在130°C的老化温度下，观察到所有RBDPO和CO的纸张老化速率显著增加。
