Miscibility of polysulfone blends with poly(1‐vinylpyrrolidone‐co‐styrene) copolymers and their interaction energies

Abstract

The miscibility of polysulfone (PSf) with various hydrophilic copolymers was explored. Among these blends, PSf gave homogeneous mixtures with poly(1vinylpyrrolidone-co-styrene) [P(VP-S)] copolymers when these copolymers contained 68 -88 wt % 1-vinylpyrrolidone (VP). Miscible PSf blends with P(VP-S) copolymers underwent phase separation on heating caused by lower critical solution temperature (LCST)-type phase behavior. The phase behavior depended on the copolymer composition. Changes in the VP content of P(VP-S) copolymers from 65 to 68 wt % shifted the phase behavior from immiscibility to miscibility and the LCST behavior. The phaseseparation temperatures of the miscible blends first increased gradually with the VP content, then went through a broad maximum centered at about 80 wt % VP, and finally decreased just before the limiting content of VP for miscibility with PSf. The interaction energies of binary pairs involved in PSf/P(VP-S) blends were evaluated from the phase-separation temperatures of PSf/P(VP-S) blends with lattice-fluid theory combined with a binary interaction model. The decrease in the contact angle between water and the membrane surface with increasing VP content in P(VP-S) copolymers indicated that the hydrophobic properties of PSf could be improved via blending with hydrophilic P(VP-S) copolymers.

Phase behavior of ASDs based on hydroxypropyl cellulose

“…All investigated ASDs revealed a glass-transition temperature close to that of pure itraconazole. This is no direct evidence for amorphous phase separation as for example Raman Imaging ( Luebbert et al, 2018b ), but a strong indirect hint that also itraconazole is not fully miscible with HPC-UL and at least some of the here-investigated ASDs underwent amorphous phase separation ( Nyamweya and Hoag, 2000 ; Brostow et al, 2008 ; Kim et al, 2003 ).…”

Amorphous-Amorphous Phase Separation in API/Polymer Formulations

“…Formulations which undergo APS usually show two distinguishable glass-transition temperatures as long as the pure component glass-transition temperatures differ to a certain extend [ 7 ]. The presence of two glass-transition temperatures is therefore considered as the main qualitative proof for the immiscibility of API/polymer formulations [ 8 ], polymer blends [ 9 , 10 , 11 ] and amorphous mixtures of APIs and small-molecule excipients, e.g., indomethacin/citric acid [ 12 ]. However, due to the high viscosity of the formulations, demixing may take very long time and therefore the quantitative analysis of APS and determining the equilibrium compositions of the two amorphous phases is quite challenging.…”

Novel Miscible Blends Composed of Poly(ether sulfone) and Poly(1-vinylpyrrolidone-co-styrene) Copolymers and Their Interaction Energies

“…For the evaluation of the interaction energies responsible for the equilibrium phase behavior using an equation-of-state theory, pressure−volume−temperature data for each polymeric component are required so that characteristic parameters can be determined. The characteristic parameters of P(VP-S) were obtained by using the mixing rule with those of PS and PVP obtained from PVT data of each polymer. − To obtain the characteristic parameters of PES, the changes in the density of PES as a function of temperature and pressure were measured using a density gradient column and a Genimix PVT apparatus. Starting at 30 °C, PES was compressed along with 28 isotherms, spaced about 10 °C apart, up to about 300 °C, with volume data recorded at pressure intervals of 10 MPa between 0 and 100 MPa along with each isotherms.…”

“…Starting at 30 °C, PES was compressed along with 28 isotherms, spaced about 10 °C apart, up to about 300 °C, with volume data recorded at pressure intervals of 10 MPa between 0 and 100 MPa along with each isotherms. The specific volume at zero pressure for each isotherm was obtained by extrapolation using the Tait equation. − Pressure−volume−temperature data of PES homopolymer above the glass transition temperature are listed in Table . The characteristic parameters of the lattice-fluid theory were obtained by the nonlinear least-squares methods of fitting PVT data to the equation of state.…”

“…The characteristic parameters of P(VP-S) were obtained by using the mixing rule with those of PS and PVP obtained from PVT data of each polymer. [30][31][32][33][34][35] To obtain the characteristic parameters of PES, the changes in the density of PES as a function of temperature and pressure were measured using a density gradient column and a Genimix PVT apparatus. Starting at 30 °C, PES was compressed along with 28 isotherms, spaced about 10 °C apart, up to about 300 °C, with volume data recorded at pressure intervals of 10 MPa between 0 and 100 MPa along with each isotherms.…”