https://ris.utwente.nl/ws/files/6775659/Witte96phase.pdf

Phase-Separation Processes in Polymer-Solutions in Relation to Membrane Formation

1. Multifunctional Initiators. 3749 2. Multifunctional Linking Agents 3751 3. Use of Difunctional Monomers 3754 B. Star−Block Copolymers 3754 C. Functionalized Stars 3755 1. Functionalized Initiators 3755 2. Functionalized Terminating Agents 3756 D. Asymmetric Stars 3757 1. Molecular Weight Asymmetry 3757 2. Functional Group Asymmetry 3760 3. Topological Asymmetry 3761 E. Miktoarm Star Polymers 3761 1. Chlorosilane Method 3761 2. Divinylbenzene Method 3766 3. Diphenylethylene Derivative Method 3766 4. Synthesis of Miktoarm Stars by Other Methods 3770

/pdf/polymers-with-complex-architecture-by-living-anionic-3vdnrccgfu.pdf

Polymers with Complex Architecture by Living Anionic Polymerization

The permeability of poly(dimethylsiloxane) [PDMS] to H2, O2, N2, CO2, CH4, C2H6, C3H8, CF4, C2F6, and C3F8, and solubility of these penetrants were determined as a function of pressure at 35 °C Permeability coefficients of perfluorinated penetrants (CF4, C2F6, and C3F8) are approximately an order of magnitude lower than those of their hydrocarbon analogs (CH4, C2H6, and C3H8), and the perfluorocarbon permeabilities are significantly lower than even permanent gas permeability coefficients This result is ascribed to very low perfluorocarbon solubilities in hydrocarbon-based PDMS coupled with low diffusion coefficients relative to those of their hydrocarbon analogs The perfluorocarbons are sparingly soluble in PDMS and exhibit linear sorption isotherms The Flory–Huggins interaction parameters for perfluorocarbon penetrants are substantially greater than those of their hydrocarbon analogs, indicating less favorable energetics of mixing perfluorocarbons with PDMS Based on the sorption results and conventional lattice solution theory with a coordination number of 10, the formation of a single C3F8/PDMS segment pair requires 460 J/mol more energy than the formation of a C3H8/PDMS pair A breakdown in the geometric mean approximation of the interaction energy between fluorocarbons and hydrocarbons was observed These results are consistent with the solubility behavior of hydrocarbon–fluorocarbon liquid mixtures and hydrocarbon and fluorocarbon gas solubility in hydrocarbon liquids From the permeability and sorption data, diffusion coefficients were determined as a function of penetrant concentration Perfluorocarbon diffusion coefficients are lower than those of their hydrocarbon analogs, consistent with the larger size of the fluorocarbons © 2000 John Wiley & Sons, Inc J Polym Sci B: Polym Phys 38: 415–434, 2000

Gas sorption, diffusion, and permeation in poly(dimethylsiloxane)

A theory has been developed which predicts the minimum permeability that can be expected for a polymer filled with platelike particles. Models are also developed for the permeability of liquids through filled polymers when the liquid adsorbs or collects at the filler-polymer interface. Some of the cases discussed include different types of dispersions, orientation of filler particles, and the effects of filler aggregation. Permeability, especially of liquids, is extremely complex, and many different types of behavior can be expected.

Models for the Permeability of Filled Polymer Systems

Fouling release coatings: a nontoxic alternative to biocidal antifouling coatings.

The diffusion and clustering of water vapour in polymers

Solution and diffusion in silicone rubber I—A comparison with natural rubber

Adsorption and desorption diffusion time lags are given for some homogeneous hollow cylinder and spherical shell membrane systems. The treatment relates to a constant diffusion coefficient with solution or sorption obeying Henry's law. Time lags for both “forward” and “reverse” flow have been determined and identities between them derived. For the hollow cylinder and spherical shell membrane systems considered here, there are only three distinguishable time lags.

James A. Barrie

Papers

The diffusion and clustering of water vapour in polymers

Solution and diffusion in silicone rubber I—A comparison with natural rubber

Time lag in diffusion

The diffusion and solution of gases in highly crosslinked copolymers

The sorption and diffusion of water in epoxy resins