Synthesis and characterization of a novel rosin-based monomer: free-radical polymerization and epoxy curing

Rosin, an abundant raw material from pine trees, has attracted much attention due to its use as a feedstock for the preparation of polymers in the age of the depletion of crude oil. Maleopimaric acid (MPA) is one of most impor-tant rosin derivatives obtained via Diels-Alder reaction between gum rosin and maleic anhydride. In this article, the authors reported a synthetic strategy to prepare a novel vinyl ester of MPA (AMPA) by sequential reaction of MPA with oxalyl chloride and allyl alcohol. The structure and properties of AMPA were characterized by fourier transform infrared spectroscopy (FT-IR), gas chromatography–mass spectrometry, 1 H NMR, 13 C NMR and differential scanning calorimetry (DSC). The results showed that AMPA has high purity and could undergo free-radical polymerization. In particular, AMPA was used as a curing agent to carry out noniso-thermal curing reaction with epoxy resin by DSC, and cured polymers were characterized by FT-IR and thermogra-vimetric analysis. The results suggested that AMPA has a great potential to prepare rosin-based unsaturated resin and epoxy resin.