Study on the Low Temperature Aging Performance of Acrylic Rubber Under Oil Immersed and Pressurized Conditions

A high and low temperature cycling aging test under oil immersion and pressurization was conducted on acrylate rubber (ACM) to rapidly assess its potential as a transformer sealing material in extremely cold regions. The effect of aging on ACM was systematically studied by Hardness Test, Permanent Compression Set Test, Fourier Trans form Infrared Spectrometer (FTIR) and Differential Scanning Calorimetry (DSC). With prolonged aging, FTIR analysis showed no significant changes, indicating that the molecular chain structure of ACM remained largely intact during lowtemperature aging. Meanwhile, both the hardness and the glass transition temperature (Tg) exhibited an upward trend, reflecting increased chain rigidity. Permanent compression set test results showed a gradually decline in elasticity over time, indicating poor deformation recovery. Taken together, these findings suggest that while ACM demonstrates good structural stability under extremely low-temperature aging conditions, its reduced flexibility and elasticity may limit its suitability for sealing applications in extremely cold environments.