Renewable Beta-Elemene Based Cyclic Carbonates for the Preparation of Oligo(hydroxyurethane)s

Abstract

Conversion of β-elemene into new β-elemene dicarbonates through epoxidation and halide salt-catalyzed CO₂ cycloaddition reactions is reported. Step-growth polyaddition of this dicarbonate to five different, commercial diamines was investigated under neat conditions at 150 °C yielding non-isocyanate-based low molecular weight oligo(hydroxyurethane)s with 1.3≤M_n ≤6.3 kDa and 1.3≤Ð≤2.1, and with glass transition temperatures ranging from -59 to 84 °C. The preparation of one selected polyhydroxyurethane material, obtained in the presence of Jeffamine® D-2010 was scaled-up to 43 g. The latter, when combined in a formulation using Irgacure® 2100 and Laromer® LR 9000 allowed the preparation of coatings that were analyzed with several techniques showing the potential of these biobased oligourethanes towards the preparation of commercially relevant materials.

Keywords: amine reagents; beta-elemene; carbon dioxide; cyclic carbonates; polyurethanes.