Abstract：With the development of new insulation materials, vegetable oil—the best substitute for mineral oil—has gradually been widely used in the liquid insulation of transformers. To investigate the influence of vegetable oil on the thermal aging rate of cellulose paper, kraft paper impregnated with mineral oil and vegetable oil underwent thermally accelerated aging at three different temperatures. degree polymerization(DP)of Kraft paper was measured to indicate the aging degree of insulation paper. The aging rate of paper in mineral oil and vegetable oil was compared quantitatively, and results showed that vegetable oil retarded paper’s degradation rate and extended its useful lifetime. The reasons contributing to such phenomenon were analyzed using X-ray Photoelectron Spectroscopy(XPS)and molecular simulation software. Kraft paper in vegetable oil had larger activation energy. Due to the larger interaction force between water and natural ester molecules, water molecule was easily bonded with natural ester, weakening the hydrolysis process of cellulose. Cellulose was chemically modified by natural ester during thermal aging process, and the reactive-OH(hydroxyl) groups on the cellulose became esterified with fatty acid esters. The water molecule was firmly bounded to the ester groups on glucose produced by esterification. The long-chain fatty acid esterified to cellulose was parallel with cellulose chains and acted as a “water barrier” to further weaken the hydrolysis process.
杨丽君, 廖瑞金, 孙才新, 尹建国, 朱孟兆. 植物油对油浸绝缘纸老化速率的影响及机理[J]. 电工技术学报, 2012, 27(5): 26-33.
Yang Lijun, Liao Ruijin, Sun Caixin, Yin Jianguo, Zhu Mengzhao. Influence of Vegetable Oil on the Thermal Aging Rate of Kraft Paper and Its Mechanism. Transactions of China Electrotechnical Society, 2012, 27(5): 26-33.
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2012, Vol. 27 
