Polystyrene-polyethylene glycol composite

This is a composite of 1 % cross-linked polystyrene and covalently attached polyethylene glycol (PEG) (2000-3000 Da). One form, sold under the name TentaGel (Rapp Polymere), is made by polymerizing ethylene oxide on to a primary alcohol located on the cross-linked polystyrene [22,23], A second form, sold under the name PEG-PS (Perseptive), is made by attaching, through the formation of an amide bond, an already formed amino terminal PEG chain (Jeffamine) to 1% cross-linked polystyrene [24], The loading capacities for both types of supports are typically in the range of 0.2-0.3 mmol amine/g resin. 

---

Figure 4.4 Composition dependence of the Hory-Huggins interaction parameter Xn for physically distinct cases of mixtures of cyclohexane-polystyrene (dotted lines) and water-polyethylene glycol (solid lines), utilizing the data of (Bae et al, 1993) for several temperatures. 4>i is the volume fraction of the small-molecule solvent. For cyclohexane-polystyrene the assumption of composition independence of Xu is qualitatively satisfactory the lowest curve there is the r = 60°C data. For water-polyethylene glycol the assumption of composition independence of Xn is less satisfactory the upper curve there is the T = 40°C data, and the lower curve corresponds to F = 30 °C. The data were analyzed on the basis of Eq. (4.63), determining the value Xi2(4>i = 0) by fitting the empirical data to the form (c j - [<(>i]niin)Ti2( i = 0)> with the minimum...

Apart from the nse of a polymerizable alkoxysilane, silica/polystyrene composite particles with a raspberry-like morphology have been elaborated in the presence of a methyl methacrylate-terminated polyethylene glycol macromonomer. This macromonomer is mainly hydrophilic due to the presence of ethylene oxide repeat units (n 23), which are able to form hydrogen bonds with the silanol groups of silica and adsorb on its snrface. In addition, this molecnle contains a methacrylate functionality able to copoljmerize with styrene thus... 

Quaternary ammonium (3) and phosphonium ions (61), crown ethers such as (62), cryptands such as (63) and poly(ethylene glycol) ethers (64) bound to PS are catalysts for reactions of water insoluble organic compounds with organic insoluble inorganic salts. " Silica gel, alumina, polystyrene-polypropylene composite fibers, nylon capsule membranes, and polyethylene (Mn 1000-3000) have also been used as supports. The reactions are called phase-transfer-catalyzed because one or both of the reactants are transported from the normal liquid or solid phase into a polymer phase, where the reaction proceeds. 

---