Bio-Based Non-Isocyanate Urethane Derived from Plant Oil

• DOI: 10.1007/s10924-012-0491-9
• Publication Date: 2012-07-21T23:01:14Z
• Authors: A. R. Mahendran; N. Aust; G. Wuzella; U. Müller; A. Kandelbauer
• Keywords: Isocyanate; Molar mass

A new bio-based non-isocyanate urethane was obtained by the reaction of a cyclic carbonate synthesized from a modified linseed oil and an alkylated phenolic polyamine (Phenalkamine) from cashew nut shell liquid. The incorporation of functional cyclic carbonate groups to the triglyceride units of the oil was done by reacting epoxidized linseed oil with carbon dioxide in the presence of a catalyst. Structural changes and changes in molar mass during the carbonation reaction were characterized using infrared spectrometry (FTIR) and chromatography. The aminolysis reaction of the cyclic carbonate with phenalkamine was monitored using real-time FTIR at 80 and 100 °C, respectively. The decay of the carbonate groups and the appearance of the newly built C=O groups of the urethane linkages were measured in situ through real-time FTIR spectra in dependence on the reaction time. Oscillatory time sweep measurements were used to monitor the viscoelastic properties of the system at 80 and 100 °C. The time of gelation was determined from rheometric measurements. Changes of the apparent activation energy with respect to the conversion of the reaction were calculated from isothermal measurements using Vyazovkin’s free kinetic model.