Molecular LEGO blocks having two reversible covalent bond moieties were employed to synthesize corresponding molecular LEGO block polymers. Hydrophilic and hydrophobic molecular LEGO blocks having two furan moieties were synthesized. These molecular LEGO blocks were polymerized with a molecular LEGO block having two maleimide moieties under Diels-Alder conditions. The resulting molecular LEGO block polymers were obtained in good yield. The molecular LEGO block polymers were depolymerized under retro-Diels-Alder conditions. In addition, these polymers proceeded in a scrambling reaction between the molecular LEGO block polymers and other molecular LEGO blocks. (C) 2016 Elsevier Ltd. All rights reserved.