A series of 2,2-dialkylpropane-1,3-diamines were synthesized and evaluated as potential phase-changing CO2 sorbents. In general, these compounds readily absorbed CO2 to form solid carbamate salts, which were relatively insensitive to the presence of moisture. This is one of the key performance attributes phase-changing sorbents must possess. However, these diamines were found to be less thermally stable in air than expected. The main reaction products obtained during heat aging at 150 degrees C appeared to be 1,4,5,6-tetrahydropyrimidine derivatives.