Microporous polymelamine network was prepared through one-pot catalyst-free polymerization using the Schiff base reaction. Gas adsorption experiments indicate that the network possesses high CO2 uptake capacity, reaching 89.0 cm(3) g(-1) (17.9 wt%) at 1.0 bar and 273 K, along with high selectivity towards CO2 over N-2 and CH4. The porous polymeric network presents a promising potential as efficient adsorbents in clean energy applications. (C) 2012 Elsevier Ltd. All rights reserved.