Polydimethylsiloxane polyether

Martin D.J., Warren L.A.P., Gunatillake P.A., McCarthy S.J., Meijs G.F., and Schindhelm, K. Polydimethylsiloxane/polyether-mixed macrodiol-based polyurethane elastomer. Biomaterials, 21, 1021, 2000. 

D. Martin, L. Warren, P. Gunatillake, S. McCarthy, G. Meijs, K, Schindhelm, Polydimethylsiloxane/polyether-mixed macrodiol-based polyurethane elastomers biostability. Biomaterials 21 (10) (2000) 1021-1029. 

For polyethers in polysiloxanes, allyl or butyl alcohol (R ) is commonly used as a starting molecule. The most popular monomers for polyethers are ethylene oxide (EO), propylene oxide (PO), and mixtures thereof. The effect of their ratio can be described with the hydrophilic-lipophilic balance (FILB) concept, which will be discussed later [11]. The higher the PO content, the more hydrophobic is the corresponding polyether. Thus, by varying the composition of the polyethers, sometimes denoted as polyoxyalkylene, it is possible to adjust the polarity of the polydimethylsiloxane polyether copolymer. A macroscopic measure for the polarity of both polyethers and polyethersi-loxanes is the cloud point of a 1% aq. solution. The higher it is, the more hydrophilic is the molecule. In this chapter we will denote these compounds as polyethersiloxanes. It is possible to design silicone surfactants that are suitable for aqueous and nonaqueous systems. 

Surface active agents are important components of foam formulations. They decrease the surface tension of the system and facilitate the dispersion of water in the hydrophobic resin. In addition they can aid nucleation, stabilise the foam and control cell structure. A wide range of such agents, both ionic and non-ionic, has been used at various times but the success of the one-shot process has been due in no small measure to the development of the water-soluble polyether siloxanes. These are either block or graft copolymers of a polydimethylsiloxane with a polyalkylene oxide (the latter usually an ethylene oxide-propylene oxide copolymer). Since these materials are susceptible to hydrolysis they should be used within a few days of mixing with water. 

TABLE 1. Comparison of tensile properties of bis(4-isocyanatocyclohexyl) methane-basedpolydimethylsiloxane-urea and polyether/polydimethylsiloxane-nrea segmented copolymers. 

Chem. Descrip. Sol n. of a polyether modified polydimethylsiloxane in alkylbenzenes/xylene (6/1)... 

Chem. Descrip. Polyether modified acryl functional polydimethylsiloxane CAS 90164)0-6... 

CAS 64365-23-7 68937-54-2 68938-54-5 Synonyms Dimethylmethyl (polyethylene oxide) siloxane Dimethylsilox-ane/glycol copolymer Polyoxyethylene-grafted polydimethylsiloxane Polysiloxane polyether copolymer Siloxanes and silicones, dimethyl, hydroxy-terminated, ethoxylated propoxylated Classification Silicone glycol surfactant... 

A metal overlayer ATR-FTIR technique which markedly enhances the SNR of monolayer and submonolayer film spectra has been described. The metals investigated were gold and aluminium, with a substrate of polyether-urethane elastomer (375). The use of silver films under ATR geometry has improved the detection limit of the surface layer on polymer films. An enhancement factor of 10 and 2 is reported for polydimethylsiloxane and polycarbonate respectively, compared to the conventional ATR technique (362). 

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