Biobased Epoxies Derived from Myrcene and Plant Oil: Design and Properties of Their Cured Products

[Image: see text] Two biobased epoxy resin monomers derived from myrcene and plant oil are synthesized without using petroleum-based bisphenol A. To obtain material with balanced strength and toughness, the two epoxy monomers are cured together in different weight proportions. Properties of cured epoxy resin are tested by different techniques. Tensile and impact tests indicate that when the content of myrcene-based epoxy is 50–75 wt %, the cured sample has a high strain of 32.30–161.47%, and a moderate tensile strength of 9.57–15.96 MPa. Dynamic mechanical analysis suggests that the glass transition temperature (T(g)) of cured samples increases from 17 to 71 °C with the increasing content of myrcene-based epoxy. Morphology of fracture surface indicates that the cured sample containing plant oil-based epoxy resin shows obvious plastic deformation. The curing kinetics of the two epoxies resin is studied by differential scanning calorimetry. Also, the calculated activation energy is 70.49 kJ/mol for myrcene-based epoxy and 64.02 kJ/mol for poly-fatty acid-derived epoxy resin. The thermogravimetric analysis indicates that the main degradation temperature of all cured samples is above 300 °C. The sustainable biobased epoxy has some potential in preparing flexible epoxy materials and can be used to toughen conventional petroleum-based epoxy.