微纤化/纳米纤维素复合绝缘纸的力学特性及计算方法

The insulation paper in oil-paper insulated transformer is in the environments of strong mechanical vibration and mechanical impact, thus the strength of the insulation paper and the ability to resist deformation are highly required. Therefore, effective enhancement and accurate prediction of mechanical properties are crucial in the application of insulating paper. In this paper, by bulk phase doping of micro/nano cellulose, modified insulating paper with different mass fractions of nanocellulose whiskers, nanocellulose fibers and microcellulose were prepared. The microscopic morphology, stress-strain curves and Young’s modulus of the micro/nano cellulose-modified insulating paper were measured with the doping concentration; moreover, the modification effects of micro/nano cellulose with different aspect ratios on the mechanical properties of the insulating paper were compared. The mechanism of micro/nano cellulose modification on insulating paper was analyzed in terms of its strength, morphology, interface, and agglomeration. Based on the detailed experiments results and comprehensive analysis, by analyzing the role of filler modification in the ideal condition based on the Halpin-Tsai model, the prediction of Young’s modulus of modified insulating paper with different doping concentrations was achieved by considering the effects of agglomerated and interfacial phases. Independent experimental validation shows that the error of the proposed prediction model is less than 1.57%. This study is very benficial for nano modification and mechanical property prediction of cellulose paper.