Student Colloquium Paper
Development of sustainable rubber entails not only inclusion of renewable synthons, but also a judicious choice of green manufacturing methodology. The acyclic monoterpene: β-myrcene, having a conjugated double bond, resembles the chemical structure of various petro based unsaturated hydrocarbon and is thus quite interesting. We have employed environmentally benign emulsion polymerization method to prepare elastomers from β-myrcene. Apart from the polymyrcene homopolymer, copolymers were also synthesized. From the spectroscopic measurement, it was found that the polymyrcene possesses 3,4 and 1,2 vinyl defects along with 1,4-cis and -trans microstructures, whereas the microstructure of the copolymers vary with the amount of co-monomer. The molecular weight of the polymers was in the range of 93,200 to 36,000 Dalton, whereas the glass transition temperature was in between -69.0 to -35.2 °C depending on the co-monomer percentage. To evaluate the properties, polymyrcene and 70/30 β-myrcene/styrene copolymer were compounded and vulcanized. The later vulcanizate showed a tensile strength of 6.4 MPa and 400 % elongation at break along with superior dynamic mechanical properties over a conventional tyre tread compound. The present study therefore paves a green tarmac for the synthesis of terpenebased elastomers as a sustainable material of the future.