Thermal processing of soybean oil to obtain bio-based polymers and bio-oil

• Soybean oil is rich was thermal processed to produce biopolymer and bio-oils.
• The selectivity between the biopolymer and bio-oil depends upon temperature.
• The presence of a nickel complex increased the viscosity of the polymer and reduced the reaction time.
• The presence of a nickel complex increased the formation of hydrocarbons and reduced the amount of formed carboxylic acids in the bio-oil.

In this study we evaluated the use of triacylglycerides to produce bio-based resins and bio-oils suitable to be used, respectively, as a binder in printing inks (offset) and as diesel-like fuel. Soybean oil was kept under nitrogen atmosphere at temperatures ranging from 260 °C to 370 °C up to 12 h in the presence or absence of a nickel complex as a catalyst precursor. It was observed that the reaction occurs in two steps. In the first one, occurs the consumption of the double bonds via Diels–Alder to form a polymer increasing the viscosity of the material. In a second step, the pyrolysis of ester groups and the alkyd chains takes place, reducing a viscosity of the polymers. Besides, using Nickel complex as a catalyst precursor it was observed a high activity to produce polymers with higher viscosity in a shorter time than when comparing with reactions without catalyst. It were also analyzed the bio-oil formed during the reaction. It was observed that without catalyst the pyrolysis leads to the formation of high amounts of carboxylic acids with short chain. However, the presence of Nickel complex increased the formation of hydrocarbons and reduced the amount of formed carboxylic acids, strongly indicating its activity in the deoxygenation.