Green Approach toward Sustainable Polymer: Synthesis and Characterization of Poly(myrcene-<i>co</i>-dibutyl itaconate)

Abstract

Motivated by an epidemic spur in developing sustainable polymers, we report here a series of biobased random rubbery copolymers from β-myrcene and dibutyl itaconate, which have the potential to substitute commercial rubbers. These were prepared by an environmentally benign emulsion polymerization method. The copolymers had predominately 1,4 - cis and - trans -polymyrcene in their microstructure and molecular weight in the range of 13, 330–64, 700 Da. The copolymers displayed a subambient glass transition temperature between −60.3 to −33.5 °C depending on the weight percent of β-myrcene. Morphological studies unveil random placement of the two phases in the copolymer. The copolymers also showed reasonably good thermal stability over the individual homopolymers and pseudoplastic flow behavior. Monitoring of the polymerization reaction at different times and temperatures revealed a first order reaction pathway. A plausible mechanistic insight into the emulsion copolymerization was provided. The reactivity ratio of the monomers indicated quasi ideal copolymerization behavior. Molecular dynamics simulation predicted the spatial arrangements of the macromolecular chains and glass transition temperature of the copolymers, which are in accord with the experimental findings. The current study would thus pave a way for synthesizing terpene-based elastomers as a sustainable material of the future.