We report the synthesis of organic solvent resistant polytriazole membranes using a sustainable process. In the first step, the polymer was dissolved in an ionic liquid for the membrane casting and immersion in water, followed by exposure to two non-toxic diepoxy crosslinkers with different lengths. We investigated the mechanical properties by measuring the creep recovery, and we correlated these data with the physical aging and compaction during filtration. Additionally, by using dynamic mechanical analysis, we studied the polymer relaxations at high temperatures associated with the local mobility of the crosslinker segments and the polytriazole chains, discussing their effect on the membrane performance. The performance in strong polar solvents, such as N, N′-dimethylformamide, was evaluated from 25 °C to 105 °C, with permeance values in the range of 3.7–10.6 L m−2 h−1 bar−1, and molecular weight cut-off around 1000 g mol−1. This confirms that the membranes meet the requirements for organic solvent applications.