Camelina oil derivatives and adhesion properties

Camelina (Cannabis sativa) is an emerging low-input and stress-tolerant non-food oilseed feedstock in the USA. The seed contains 36-47% oil with 90% unsaturated fatty acids, which means it may be suitable for making oleochemicals and biopolymers. This paper describes the synthesis of several oleo derivatives from camelina oil (CO) and the development of polymers through UV polymerization for pressure-sensitive adhesive (PSA) applications. CO was converted into epoxidized camelina oil, then to partially acrylated epoxidized camelina oil, and finally to di-hydroxyl acrylated epoxidized camelina oil, an acrylic polyol with 1 acrylate functionality and a hydroxyl value of 293 mg KOH/g. These oil derivatives were characterized using Fourier transform infrared spectroscopy, H-1 nuclear magnetic resonance, rheometry, and differential scanning calorimetry. The acrylic polyol was copolymerized with 2-ethylhexyl acrylate (2-EHA) to form tacky viscoelastic polymers. Glass transition temperature of the polymers increased as increasing ratio of acrylic polyol to 2-EHA. A bio-based PSA with a good balance of peel strength (3.86 N/in), tack (5.2 N/in), and shear resistance (>30,000 min) was achieved with equal amounts of acrylic polyol and 2-EHA and a moderate amount of rosin ester added as a tackifier. Frequency sweeps indicated positive correlations between the adhesion performances and viscoelastic responses of PSAs. (C) 2015 Elsevier B.V. All rights reserved.