Abstract
The purpose of this paper is to study the surface energetics of the polymer excipient cellulose acetate propionate (CAP) in the solid form. The net retention volumes, V N, for n-alkanes and polar solutes have been measured in the temperature range 353.15–403.15 K by inverse gas chromatography. The dispersive surface free energy, \( \gamma_{\text{S}}^{\text{d}} \), and Lewis acid–base parameters \( K_{\text{a}} \) and \( K_{\text{b}} \), have been determined using V N values. The \( \gamma_{\text{S}}^{\text{d}} \) values are decreased linearly with increase of temperature. The \( \gamma_{\text{S}}^{\text{d}} \) value at 353.15 K is 24.50 ± 1.54 mJ/m2, and the temperature gradient was found to be −0.287 mJ/m2/K1. The \( K_{\text{a}} \) and \( K_{\text{b}} \) values are 0.410 ± 0.021 and 1.708 ± 0.388, respectively, which suggest that the CAP solid surface contain relatively more basic sites. The K a and K b values of CAP are compared with the similar values obtained on the cellulose acetate butyrate solid surface.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.