甲酸/甲醇环境中密封橡胶的溶胀行为与力学性能研究

Study on the Swelling Behavior and Mechanical Properties of Sealed Rubber in Formic Acid/Methanol Environment

摘要: 在“双碳”战略背景下，甲醇作为清洁能源和储能介质的重要性日益提升，其长距离管道输送中的密封材料溶胀问题已成为关键挑战。本文系统研究了丁腈橡胶(NBR)、氟橡胶(FKM)和硅橡胶(VMQ)在含甲酸的甲醇环境中的溶胀行为与力学性能变化。结果表明，甲酸显著抑制橡胶溶胀，但同时也引发材料降解，其中硅橡胶因Si-O键水解而出现“负溶胀”现象。温度升高加剧了溶胀与降解的竞争效应，高压则普遍抑制溶胀进程。力学性能测试显示，氟橡胶在甲酸环境中的抗拉强度下降高达45.9%，而丁腈橡胶表现出最优的稳定性。本研究为甲醇输送系统中密封材料的选型与安全性评估提供了重要依据。

Abstract: Under the backdrop of the “Dual Carbon” strategy, methanol is gaining increasing importance as a clean energy source and energy storage medium. The swelling of sealing materials in its long-distance pipeline transportation has become a critical challenge. This paper systematically investigates the swelling behavior and changes in mechanical properties of nitrile rubber (NBR), fluororubber (FKM), and silicone rubber (VMQ) in a methanol environment containing formic acid. The results indicate that formic acid significantly inhibits rubber swelling but also induces material degradation. Silicone rubber exhibited “negative swelling” due to the hydrolysis of Si-O bonds. Elevated temperatures intensified the competing effects of swelling and degradation, while high pressure generally suppressed the swelling process. Mechanical tests revealed that the tensile strength of fluororubber decreased by up to 45.9% in the formic acid environment, whereas nitrile rubber demonstrated the optimal stability. This study provides important insights for the selection and safety assessment of sealing materials in methanol transportation systems.