A polychloromethylstyrene-b-polypolycyclooctene-b-polychloromethylstyrene ABA triblock polymer was used as a backbone in a study to produce a chemically and mechanically robust anion exchange membrane (AEM). The material is easily scalable and the polypolycyclooctene segment (low T-m) makes the membrane flexible to handle. Comparison of the non-crosslinked triblock polymer functionalized with different cations namely; piperidinium, pyrrolidinium, tris(2,4,6-trimethoxyphenyl) phosphonium, and the benchmark trimethylammonium cation showed that the piperidinium functionalized membrane with an ionic exchange capacity of ca. 1.36 mmol.g (-1) had the highest OH- conductivity ca. 95 mS.cm(-1) at 80 degrees C, 95% RH, and the highest Cl- conductivity of ca. 31 mS.cm at 70 degrees C, 95% RH. The membrane with the piperidinium cation was the most chemically stable when immersed in 1 M KOH at 80 degrees C (with only 16% degradation after 14 days) compared to all the other cation functionalized membranes studied here. Photo-crosslinking with 1,10-decanedithiol (DT) eliminated the melting behavior of the polycyclooctene black and improved the mechanical stability of the films allowing < 20 mu m large area transparent membranes to be produced. The DT cross-linking reduced the membrane swelling on all length scales as shown by small angle X-ray scattering, water uptake, and dimensional swelling data, and allowed the membrane to be fully intact even at fully hydrated states based on the tensile strength measurements.