Oleochemical carbonates: A comprehensive characterization of an emerging class of organic compounds

Authors: TRIOLO, ALESSANDRO - Consiglio Nazionale Delle Ricerche; CHABAN, V - Yerevan State University; LO CELSO, F - Consiglio Nazionale Delle Ricerche; LEONELLI, F - University Of Rome Sapienza; VOGEL, M - Technical University Of Darmstadt; STEINRUCKEN, E - Technical University Of Darmstadt; DEL GIUDICE, A - University Of Rome Sapienza; OTTAVIANI, C - Consiglio Nazionale Delle Ricerche; Kenar, James - Jim; RUSSINA, O - Consiglio Nazionale Delle Ricerche

Submitted to: Journal of Molecular Liquids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2022
Publication Date: 11/26/2022
Citation: Triolo, A., Chaban, V.V., Lo Celso, F., Leonelli, F., Vogel, M., Steinrucken, E., Del Giudice, A., Ottaviani, C., Kenar, J.A., Russina, O. 2022. Oleochemical carbonates: A comprehensive characterization of an emerging class of organic compounds. Journal of Molecular Liquids. 369. Article 120854. https://doi.org/10.1016/j.molliq.2022.120854.
DOI: https://doi.org/10.1016/j.molliq.2022.120854

Interpretive Summary: Oleochemical carbonates are a class of biobased materials that can be prepared from plant oils that are attracting attention for lubricant and personal care applications due to their appealing flammability, toxicity, and viscosity attributes. However, basic understanding how their chemical physical properties are influenced by temperature, needed to effectively utilize these compounds, is lacking. This research examined a series of these oleochemical carbonates and provides new fundamental knowledge important to researchers and industry that extends previously determined data bases and provides a more complete picture as to how their properties depend on temperature.

Technical Abstract: Dialkyl carbonates (DAC) with short-medium alkyl length - oleochemical carbonates – are attracting attention because of their appealing properties, including low viscosity, flammability, toxicity, environmental impact and wide range of applications: lubricants, personal care, fuel additives etc. However, not much is known on their chemical physical properties and, more importantly on the nature of microscopic correlations that eventually determine bulk performances. In view of this paucity, here, we present a large exploration of a series of chemical physical properties of a set of DACs ranging from dimethyl up to didodecyl carbonate. This study extends previously determined data bases, thus providing a complete picture of the temperature dependence of chemical physical properties around room temperature. Furthermore, we explored the microscopic morphology of DACs, by synergic exploitation of X-ray scattering and Molecular Dynamics techniques. These tools allow detecting the existence of a distinct degree of mesoscopic spatial segregation between polar carbonate moieties and apolar alkyl chains domains. The role of first neighbour carbonate moieties in driving the corresponding molecules towards weak hydrogen bonding interactions and alkyl chain alignments is described. Such an effect is related to the overall mesoscopic segregation of alkyl tails that isolate small droplets formed by stacked carbonate groups. Such a highly compartmentalised morphology can explain and potentially suggest applications of DACs in fields as relevant as separation, catalysis, lubrication etc.