Rapeseed oil as feedstock for the polymeric materials via Michael addition reaction

Abstract

Rapeseed oil was used to synthesize a Michael donor to obtain polymeric materials after nucleophilic polymerization via Michael reaction. Four different bio-polyols as precursors for the Michael donor monomer synthesis were synthesized from epoxidized rapeseed oil using an oxirane ring-opening reaction. Various alcohols such as methanol, butane-1,4-diol, 2,2′-oxydi(ethan-1-ol), and 2-ethyl-2-(hydroxymethyl)propane-1,3-diol were used to obtain bio-polyols with different OH group functionality. The transesterification reaction between the synthesised bio-polyol hydroxyl groups and tert-butyl acetoacetate ester introduced acetoacetate functional groups into their structure. The acid value, hydroxyl value, viscosity and moisture content of the synthesized polyols and corresponding acetoacetates were analyzed. Size-exclusion chromatography and Fourier transform infrared spectroscopy were used to study the chemical structure of polyols and acetoacetates. From developed acetoacetates and commercially available trimethylolpropane triacrylate, bio-based polymers were obtained via carbon-Michael reaction. The different chemical structures and functionalities of the synthesized bio-based monomers allowed for the development of polymer formulations with diverse cross-linking densities. The structural, physical and thermal properties of the developed polymers were analyzed using solid-state NMR, differential scanning calorimetry, dynamic mechanical analysis and thermal gravimetric analysis testing apparatus.