Industrial & Engineering Chemistry Research, Vol.58, No.46, 20946-20960, 2019
Redox Emulsion Polymerization of Terpenes: Mapping the Effect of the System, Structure, and Reactivity
Synthesis of biobased polymers from renewable feedstocks has been the focus of research on sustainability. The family of acyclic terpenes, particularly beta-myrcene, beta-ocimene, and beta-farnesene from renewable feedstocks, imparts a classical chemistry close to isoprene (unsaturated hydrocarbon from petroleum). In this work, redox emulsion polymerization of these terpenes was carried out. The polymerization of beta-myrcene produced a high molecular weight rubbery polymer (M-n = 1.68 x 10(5) Da) with a maximum yield of 65%. The spectroscopic measurements showed that polymyrcene predominantly contained a 1,4- microstructure. The polymyrcene from the best redox initiator system was characterized in detail. Its microstructure was established using 1D and 2D NMR spectroscopy. Polymyrcenes synthesized using different recipes displayed a glass transition temperature from -70 to -58 degrees C, indicating a rubbery nature. However, beta-ocimene and beta-famesene polymerization yielded low molecular weight polymers with preferable 1,4-addition products. Density functional theory provided the ground state-optimized structure of terpenes.