In this study 4-methylpyridine (4MP), 4-vinylpyridine (4VP) and poly(4-vinylpyridine) (P4VP) were separately reacted with epoxidized soybean oil triglycerides (ESO) to give plant oil based thermoset polymers. The addition reaction of pyridine with epoxide followed by a rearrangement results in formation of pyridone units and these were polymerized via a Diels-Alder reaction. DMA, DSC, TGA and IR spectroscopy were used for the characterization of the products. 4MP-ESO, P4VP-ESO and P4VP-ESO-in situ polymers were crosslinked yielding rigid infusible polymers. Glass transition temperatures (T(g)) of 4MP-ESO and P4VP-ESO-in situ were found as -10.5 and 70.5 (32.3 as shoulder) degrees C respectively, by DMA analysis. Storage moduli of 4MP-ESO and P4VP-ESO-in situ at 25 degrees C were 13.7 and 187.2 MPa, respectively. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121:2976-2984, 2011