Melting Point Depression of Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Triblock Polymers in Supercritical Carbon Dioxide in the Presence of Menthol as a Solid Co-Plasticiser

Vivek Trivedi; Adejumoke Lara Ajiboye; Nichola J Coleman; Ruchir Bhomia; Marion Bascougnano

doi:10.3390/polym14142825

Melting Point Depression of Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Triblock Polymers in Supercritical Carbon Dioxide in the Presence of Menthol as a Solid Co-Plasticiser

Polymers (Basel). 2022 Jul 11;14(14):2825. doi: 10.3390/polym14142825.

Authors

Vivek Trivedi¹, Adejumoke Lara Ajiboye¹, Nichola J Coleman², Ruchir Bhomia³, Marion Bascougnano²

Affiliations

¹ Medway School of Pharmacy, University of Kent, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK.
² Department of Pharmaceutical, Chemical and Environmental Science, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK.
³ Procter & Gamble, 452 Basingstoke Road, Reading RG2 0RX, UK.

Abstract

The melting behaviour of the triblock polymers, Pluronic F38, F68, F77, F108, and F127, was investigated in pressurised CO₂ and in the presence of menthol. The melting points of the polymers combined with 0, 10, 25, and 50 wt% of menthol were studied at atmospheric pressure and compared with those at 10 and 20 MPa in supercritical carbon dioxide (scCO₂). The highest melting point depressions of 16.8 ± 0.5 °C and 29.0 ± 0.3 °C were observed at 10 and 20 MPa, respectively. The melting point of triblock polymers in pressurised CO₂ was found to be dependent on molecular weight, poly(propylene oxide) (PPO) content, and menthol percentage. The melting point of most of the polymers studied in this work can be reduced to room temperature, which can be pivotal to the formulation development of thermolabile substances using these polymers.

Keywords: melting point depression; solid co-plasticiser; supercritical carbon dioxide; triblock polymers.

Grants and funding

This research received no external funding.