- Generic, metal-free cross-linking and modification of silicone elastomers using click ligation
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Silicone elastomers are widely used in a variety of biomaterials applications. Their high hydrophobicity can, in some cases, compromise their utility. There exist few convenient, efficient and metal-free processes to introduce hydrophilic groups onto the elastomer surface. We describe the utilization of the metal-free click reaction between azido- and alkynyl-modified silicones to both cross-link and functionalize silicone elastomers. Initial cross-linking at, optionally, reduced or elevated temperatures depending on the alkyne used, results in elastomers whose moduli and tackiness can be controlled by manipulation of cross-link density through use of different chain length constituents: the systematic capping of azides on the azide-rich partner provides a level of control of both cross-linking and residual functionality after cross-linking. The residual azides or alkynes resulting from nonstoichiometric mixing of the starting materials can be used for sequential functionalization of the elastomer as shown through the improved wettability that results from the grafting of alkyne-functional PEG to azide-rich silicone elastomers: contact angles decrease from ~105° for the pure silicone elastomers to 85° for the azide-rich silicone elastomer, and to as low as 41° for the PEG-modified product. It is possible to modify the entire elastomer body or only the surface by judicious choice of the solvent used for the hydrophilic modification.
- Rambarran, Talena,Gonzaga, Ferdinand,Brook, Michael A.
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- HYDROXYBENZOPHENONE DERIVATIVES
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Disclosed are hydroxyphenylbenzophenone derivatives of formula (1), wherein R1 and R2 independently from each other are hydrogen; C1-C20alkenyl; C3- C10cycloalkyl; or R1 and Rsu
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Page/Page column 11
(2008/06/13)
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- Composition for separating mixtures
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Therefore, there is provided herein in one specific embodiment a composition comprising: a) at least one silicone surfactant, and where silicone of silicone surfactant (a) has the general structure of: [in-line-formulae]Ma1Mb2Dc1Dd2Te1Tf2Qg; [/in-line-formulae][in-line-formulae]and, [/in-line-formulae][in-line-formulae]2≦(a+b+c+d+e+f+g)≦100; and, [/in-line-formulae] b) a mixture comprising an aqueous phase, a solid filler phase and optionally an oil phase that is substantially insoluble in said aqueous phase.
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Page/Page column 21-22
(2008/06/13)
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