Effect of Thermo-Oxidative Ageing on Aviation Polysulfide Sealants

• Published in: Applied Mechanics and Materials Vol. 152-154; no. Mechanical Engineering and Materials; pp. 28 - 33
• Main Authors: Wang, Yun Ying, Meng, Jiang Yan
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.01.2012
• Subjects: Aeronautics; Aging; Aviation; Hardness; Measuring instruments; Meters; Sealers; Shores; Artificial Accelerated Thermo-Oxidative Ageing; Dynamic Mechanical Analysis (DMA); Aviation Polysulfide Sealant
• ISBN: 9783037853528; 3037853522
• ISSN: 1660-9336; 1662-7482; 1662-7482
• DOI: 10.4028/www.scientific.net/AMM.152-154.28

Aviation polysulfide sealants have been subjected to thermo-oxidative ageing. Their morphologies, Shore A hardness, and tensile properties have been tested by means of an optical microscope, a glossiness meter, a Shore A hardness meter, and a universal testing machine. Changes in their microstructures were measured by Fourier-transform infrared spectroscopy and dynamic mechanical analysis (DMA). The results showed that glossiness was gradually reduced, and bubbles appeared on the surface of the samples during the course of ageing. The Shore A hardness of the sealant first decreased and then remained unchanged. Likewise, the tensile strength and tensile elongation percent first decreased and then remained unchanged. The infrared monitoring showed that the sealant underwent a post-cure reaction. The glass transition temperature and the room-temperature storage modulus of the sealant remained unchanged. No new functional groups were formed during ageing of the sealant. The aviation sealants did not undergo chemical degradation, showing that they have good endurance under thermo-oxidative conditions.