In this work, a diene ester monomer, 2-(10-undecenoyloxy)-ethyl methacrylate (MHU), was synthesized by the enzymatic esterification of 10-undecenoic acid (derived from castor oil) and 2-hydroxyethyl methacrylate and employed in two different ways: (1) in thiol-ene polymerization with 1,4-butanedithiol (1,4-BDT) and (2) as a precursor in a Michael addition reaction with hexamethylenediamine. In thiol-ene bulk polymerization of the asymmetrical diene monomer MHU, which presents different reactivities for each double bond, higher molecular weights (up to 44.3 kDa) were reached when nonstoichiometric thiol-ene ratios were used. In the second approach, Michael addition allowed us to obtain a symmetrical diene monomer that was used to produce a polymer (11.3 kDa) containing both amine and ester groups by thiol-ene polymerization. Finally, for the same MHU/1,4-BDT molar ratio, miniemulsion thiol-ene polymerization resulted in higher molecular weights (up to 17 kDa) when compared with those from bulk polymerization (8.7 kDa).