Synthesis and molecular dynamics simulation of biobased “bottle-brush” polyfarnesene via aqueous radical polymerization

Abstract

The farnesene monomer, obtained through bio-fermentation, offers a unique long side chain structure that serves as an excellent platform for the synthesis of bottle-brush polymers with exceptional thermal properties. Such polymers have immense potential in the production of polyurethane elastomers and adhesives. Molecular dynamics simulations of polyfarnesene were performed using Materials Studio to calculate pivotal mechanical parameters like glass transition temperature (Tg), cohesive energy density (CED), and free volume. The Tg was verified by comparing the results from the simulations with measured values obtained through experimental tests. Additionally, hydroxyl-terminated polyfarnesene was cured with a variety of isocyanate cross-linking agents, using a cross-linking script, to evaluate its mechanical and energetic characteristics. The results from the simulation of trans-1,4-polyfarnesene exhibited a Tg of 202 K, which was in close agreement with the Tg (197 K) obtained from differential scanning calorimetry (DSC) measurements. Moreover, the mechanical properties of hydroxyl-terminated polyfarnesene were significantly enhanced through cross-linking, with the multi-isocyanate (N100) curing system demonstrating the highest efficacy. These findings demonstrate the usefulness of molecular dynamics (MD) simulations in providing a thorough qualitative and quantitative understanding of the intricate connection between the properties and structure of polymers.