The bulk free-radical polymerization of 2-[(N,N-dialkylamino)methyl]-1,3-butadiene with methyl, ethyl, and n-propyl substituents was studied. The monomers were synthesized via substitution reactions of 2-bromomethyl-1,3-butadiene with the corresponding dialkylamines. For each monomer the effects of the polymerization initiator, initiator concentration, and reaction temperature on the final polymer structure, molecular weight, and glass-transition temperature (T-g) were examined. Using 2,2'-azobisisobutyronitrile as the initiator at 75 degreesC, the resulting polymers displayed a majority of 1,4 microstructures. As the temperature was increased to 100 and 125 degreesC using t-butylperacetate and t-butylhydroperoxide, the percentage of the 3,4 microstructure increased. Differential scanning calorimetry indicated that all of the T-g values were lower than room temperature. The T-g values were higher when the majority of the polymer structure was 1,4 and decreased as the percentage of the 3,4 microstructure increased. The Diels-Alder side products found in the polymer samples were characterized using NMR and gas chromatography-mass spectrometry methods. The polymerization temperature and initiator concentration were identified as the key factors that influenced the Diels-Alder dimer yield.