Equation of state of aqueous polymer systems: poly(propylene glycol)+water

Abstract

The equation of state of the poly(propylene glycol) (PPG) ] water system has been measured using a vibrating tube densimeter in the intervals 0.1 O P/MPa O 40.0 and 298.15 O T /K O 328.15, and over the whole composition range. The PÈoÈT data can be well described by a generalized Tait equation. The results show that the e †ect of pressure on the relative molar volume is smaller than for both the PPG ] ethanol and PPG ] n-hexane systems. The excess volume is highly negative, and similar to that previously reported for poly(ethylene glycol) ] water. Increasing the pressure decreases both *GE and *HE. The corresponding states equation proposed by Huang and OÏConnell (Fluid Phase Equilibr., 1987, 37, 75) fails when applied to the present systems. Although the master curve proposed by Sanchez et al. (Macromolecules, 1993, 26, 4234) does not describe the PÈoÈT surface of PPG ] water with the same degree of precision as that for the PPG ] n-hexane or of PPG ] ethanol, it still can be useful for estimating high-pressure data from low-pressure isothermal compressibility data.

Tuning the Mesopore Size of Titania Thin Films Using a Polymeric Swelling Agent

“…The combination of hydrophilic (ether and hydroxyl) and hydrophobic (propyl) groups in PPG makes it soluble in a broad range of solvents, ranging from n -hexane to water . Furthermore, increasing the relative molecular weight of PPG from 400 to 1000 decreases the lower consolute temperature (LCST) in an aqueous system from above 50 to near 0 °C . The LCST of PPG with molecular weight above 2000 would be expected to be below 0 °C, although phase diagrams of aqueous PPG at these temperatures are rarely reported.…”

“…35 Furthermore, increasing the relative molecular weight of PPG from 400 to 1000 decreases the lower consolute temperature (LCST) in an aqueous system from above 50 to near 0 °C. 36 The LCST of PPG with molecular weight above 2000 would be expected to be below 0 °C, although phase diagrams of aqueous PPG at these temperatures are rarely reported. The hypothesis tested here is that, at a temperature between ambient temperature and 0 °C, PPG with molecular weight ∼3500 can be considered to be a tunable hydrophobic swelling agent for P123 micelles.…”

Thermoresponsive polymers with LCST transition: synthesis, characterization, and their impact on biomedical frontiers

“…34,123 In addition, poly(ethylene oxide) (PEO) and poly( propylene oxide) (PPO) and their copolymers with LCSTs varying from 20 °C to 85 °C contain EG units in their main chains and are commercially available under the names of Pluronics, Poloxamers, and Tetronics. [124][125][126] Amphiphilic balance in OEG structure is the main reason for the thermoresponsive property of these types of polymers. 127,128 The previous reports on thermoresponsive polymers are dominated by PNIPAM and POEGMA derivatives.…”

Experimental study of the equation of state and the surface tension of water-soluble polymers: poly(ethylene glycol)-b-poly(propylene glycol)-b-poly(ethylene glycol) + water at 298.15 K

“…In recent works we have carried out extensive experimental studies of the PÈoÈT surfaces of the systems PPG ] n-hexane, ]ethanol, and ]water. 25,26 Although it was possible to make a reasonable description of the experimental results for the non-aqueous systems using the lattice-Ñuid EoS of Panayiotou and Sanchez,27 the model did not describe the experimental data of the PPG ] water mixture. Therefore, there is a need to obtain experimental data on the equation of state of selected aqueous polymer systems which may be used for further theoretical progress.…”