Waterborne latex with renewable oil sources

Abstract

The synthesis of polymers from renewable resource monomers is receiving an increasing attention, due to the high price and future depletion of fossil fuels, together with the concerns regarding environmental sustainability. Among the existing renewable raw materials, vegetable oils appear as one of the most interesting alternatives for the chemical and polymer industry. Sunflower is grown in large extent in the Mediterranean basin, being Spain and Portugal ones of the major producing countries. Therefore, this vegetable oil can be considered as a promising candidate as a biobased starting material. Besides, any progress towards sustainability achieved by the use of renewable feedstocks will be greatly improved by the use of a solvent‐free environmentally friendly technology, such as emulsion polymerization. Thus, the aim of this project is to synthesize waterborne polymers based on sunflower oil and probe their potential as binders for the coating industry. Sunflower oil is a triglyceride, which main components are oleic acid (C18, one unsaturation, 25% aprox) and linoleic (C18, two non‐conjugated unsaturations, 65 % aprox). Those double bonds are not reactive enough for effective free radical polymerization, so the incorporation of polymerizable moiety, such as acrylic or vinyl groups, must be achieved. In the first part of this project the synthesis of the sunflower oil macromonomer (SFOM) was studied. Stable latexes with considerable solids content were synthesized and miniemulsion polymerization was the technique used for the synthesis of the latex. The resulting polymer latex was analyzed in terms of conversion, particle size and microstructural properties. Furthermore the mechanical properties of the dried films were presented.