Synthesis and Characterization of a Bio-Based Resin from Linseed Oil Arunjunai Raj Mahendran, * 1 Nicolai Aust, 2 Gu ¨ nter Wuzella, 1 Andreas Kandelbauer 3,4 Summary: The use of renewable raw materials in the polymer industries is becoming increasingly popular because of environmental concerns and the need to substitute fossil resources. Plant oils with triglyceride backbones can be chemically modified and used to synthesize polymers from renewable resources (biopolymers). In the present study, linseed oil was epoxidized using a chemo-enzymatic method based on Candida Antarctica lipase B (CALB) as a biocatalyst and the modified linseed oil was cured using maleinated linseed oil and a commercial polyamide resin. The amount of epoxidation achieved depended on the amount of lipase used and was determined by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies. With 20% (weight per weight) catalyst concentration based on the wt % of oil a degree of epoxidation of > 90% was achieved. The cross-linking reaction of epoxidized linseed oil with the maleinated linseed oil and the polyamide resin was studied using differential scanning calorimetry (DSC). DSC traces showed that an increase in epoxidation degree lead to larger values for the exothermic enthalpy integrals of the curing reactions and hence to a higher reactivity of the linseed oil towards the cross-linking agents. Keywords: biopolymers; calorimetry; infrared spectroscopy; NMR; synthesis Introduction During the last decades the attempts to develop bio-based products have increased considerably in number because of growing environmental consciousness and often lower prices of fast-growing plant based raw materials compared to products derived from petrochemical resources. The renewable materials can partially or in some rare cases [1–5] even totally replace the petroleum based polymers. The most common class of renewable materials derived as a by-product from the food industry which is used for making bio-based polymers is the vegetable oils. Such plant oils are triglycerides with varying composi- tions in fatty acids depending on the individual plant, crop type, season and growing conditions. The fatty acid moieties contribute 94–96% of the total weight of one molecule triglyceride oil and these fatty acids may be saturated, unsaturated or polyunsaturated. The number of double bonds present in the triglycerides governs the level of reactivity of the oils and the physical properties of the natural oils depend very strongly on the degree of unsaturation and the relative amounts of different fatty acids. Vegetable oils do not meet the properties desired for polymer synthesis unless they are chemically mod- ified either at the double bonds or carboxyl Macromol. Symp. 2012, 311, 18–27 DOI: 10.1002/masy.201000134 18 1 Wood Carinthian Competence Center (W3C), Kom- petenzzentrum Holz GmbH, Klagenfurterstrasse 87- 89, A-9300 St. Veit an der Glan, Austria E-mail: a.mahendran@kplus-wood.at 2 Department of Chemistry of Polymeric Materials, University of Leoben, Otto Glo ¨ ckel-Straße 2, A- 8700 Leoben, Austria 3 School of Applied Chemistry, Reutlingen University, Alteburgstrasse 150, D-72762 Reutlingen, Germany 4 Department of Wood Science and Technology, Uni- versity of Natural Resources and Life Sciences, Peter Jordan Strasse 82, A-1190 Vienna, Austria Copyright ß 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.com