Spontaneous catalyst‐free polymerizations of 4‐ethynylpyridine (4EPy) and 2‐ethynylpyridine with bifunctional quaternizing agents (QAs) of bis(bromomethyl)arenes provide highly crosslinked polymer networks in high yields. 13C cross‐polarization magic‐angle spinning (CP/MAS) NMR, Fourier transform IR (FTIR) and diffuse reflectance vis spectroscopy confirm that these networks consist of polyacetylene main chains substituted with pyridyl and pyridiniumyl groups, the latter interconnected with –CH2(arylene)CH2– linkers. Variation of the 4EPy/QA ratio in the polymerization feed results in networks with different extents of crosslinking and pyridyl/pyridin­iumyl ratio (N/N+ from 0 to 1.32). Networks exhibit photolumi­nescence and are also moderately active in CO2 capture (the highest uptake is 16.4 cm3 (STP) g−1 at 293 K and an equilibrium CO2 pressure of 750 Torr).