Functional polydimethylsiloxane

Epoxy-functional polydimethylsiloxane oligomers are another group that can be cured by UV radiation. Epoxysilicone block copolymers exhibit a good photoinitiator miscibility, high cure rate, and compatibility with epoxy and vinyl ether monomers. These block copolymers form flexible films with excellent release properties and are therefore used as release coatings. ... 

The hydrosilylation of CC-double bond-containing compounds with SiH-functional polydimethylsiloxanes is a widely applied reaction in industrial synthesis for the production of organosilicon compounds (Fig. 3) on an industrial scale [1]. 

Typically, the reaction is performed in a liquid-liquid biphasic system where the substrates and products (upper phase) are not miscible with the catalyst/ionic liquid solution (lower phase). The SiH-functional polydimethylsiloxane and the olefin are placed in the reaction vessel and heated up to 90 °C. Then the precious metal catalyst (20 ppm) and the ionic liquid (1 %) are added. After complete SiH conversion, the reaction mixture is cooled to room temperature and the products are removed from the reaction mixture by either simple decantation or filtration (in case of non-room-temperature ionic liquids). The recovered catalyst/ionic liquid solution can be reused several times without any significant change in catalytic activity. A treatment or workup of the ionic liquid-catalyst solution after each reaction cycle is not necessary. The metal content of the products was analyzed by ICP-OES (Inductively coupled plasma optical emission spectroscopy) and the chemical identity of the organomodified polydimethylsiloxane was verified by NMR spectroscopy. 

The state-of-the-art silicone systems used in label stock application are normally solventless and thermal curing. Base polymers for these systems are vinyl-functionalized polydimethylsiloxanes having viscosities of around 200 - 600 mPa.s. Cross-linkers normally are hydride-functionalized polydimethylsiloxanes with a viscosity of around 25 mPa.s. These two components are cross-linked by a platinum catalyst, which can be the Karstedt catalyst. Additionally an inhibitor is added to the silicone mixture to prevent curing before it is applied on the substrate. These inhibitors ate... 

The hydrosilylation reaction can also be conventionally conducted by reaction of an olefin and an SiH-functional polydimethylsiloxane in the presence of a standard transition metal catalyst, and after the reaction the catalyst can be extracted with an ionic liquid. In some cases, the use of an ionic liquid in the hydrosilylation process even improved the quality of flie polyethersiloxanes with respect to color compared to the standard process. An explanation might be the avoidance of catalyst reduction leading to the formation of colloidal metal particles, which tend to color the product slightly brownish. In other words, the ionic liquid seems to have a stabilizing effect on the catalyst. 

Polysiloxane-containing amphiphilic block copolymers have been prepared by different approaches. Coupling of an end-functionalized polydimethylsiloxane with a functionalized poly(ethylene oxide) led to the formation of PDMS- -PEO diblock copolymers. The sequential anionic ring-opening polymerization of tetramethyltetravinylcyclotetrasiloxane and hexamethylcyclotetrasiloxane resulted in the formation of a vinyl-substituted diblock copolymer, the vinyl groups of which could be modified by further reactions so as to import amphiphilic character. The phase behavior of short-chain PDMS-Z -PEO diblock copolymers revealed the preferred formation of lamellar phases by this type of amphiphile... 

COMPARISON OF THEORETICAL AND EXPERIMENTAL EPOXY GROUP CONCENTRATIONS IN SILANOLATE EQUILIBRATED EPOXY FUNCTIONAL POLYDIMETHYLSILOXANE OLIGOMERS... 

A series of [2.2.1]bicycloheptenyl (norbornene) functional prepol)nners have been prepared via the cycloaddition reaction of cyclopentadiene monomer with corresponding acrylics. When these materials are formulated with an appropriate multifuntional thiol crosslinker and photoinitiator and irradiated, a rapid, exothermic, crosslinking reaction takes place. When the acrylic precursors are organic resins, the derived polymers behave like toughened plastics. The choice of a norbornene functional polydimethylsiloxane precursors gives elastomeric products. 

The platinum catalyzed condensation of the a,w-hydrogen difunctional polydimethylsiloxane oligomers with 3-vinyl-7-oxabicyclo[4.1.0]heptane proceeds smoothly and quantitatively. Under the above conditions, a,w-epoxy-functional polydimethylsiloxanes with n = 17, 41, 59 and 111 were prepared as colorless and odorless mobile oils. 

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

Chem. Descrip. Amino, methoxy functional polydimethylsiloxane CAS 9016-00-6 Uses Automobile finish... 

Chem. Descrip. Alkoxylated triglyceride Uses Emulsifier tor silicone oil, amino-functional polydimethylsiloxane, coatings tood-pkg. adhesives defoamer in food-contact paper/paperboard... 

Chem. Descrip. Emulsion of a hydroxy-functional polydimethylsiloxane resin... 

The concept of Reactive Silicones comprises a great number of different silicon compounds containing various functional groups. Examples of such organofunctional silicones include hydroxy-, amino-, epoxy-, carboxy-, acryloxyalkyl- or vinyl-functionalized polydimethylsiloxanes. 

Pyrrole was copolymerized with siloxane since siloxane polymer has distinct and advantageous properties such as high temperature stability, high flexibility, and solubility in nonpolar or weakly polar solvents [55]. Figure 8.15 shows the synthesis procedure to prepare a block copolymer of pyrrole-functionalized polydimethylsiloxanes (PDMS-PPy). PDMS-PPy was polymerized by electrochemical polymerization of pyrrole on the electrode coated with the precursor PDMS-PPy. 

PPE-polysiloxane blends have also been compatibilized through copolymer formation between amine-terminated polydimethylsiloxane and either epoxy-functionalized PPE (Blohm et al. 1995) or anhydride-functionalized PPE (Shea et al. 1989). Compatibilized blends have also been formed by extmsion of PPE with epoxy-functionalized polydimethylsiloxane (Celia et al. 2002) and by kneading of anhydride-functionalized PPE with carboxylic acid-functionalized polydimethylsiloxane in the presence of a diamine coupling agent (Moritomi and Iji 2002). 

Novi, C. Mourran, A. Keul, H. Moller, M., Ammonium-Functionalized Polydimethylsiloxanes Synthesis and Properties. Macromol. Chem. Phys. 2006, 207, 273-286. 

They have studied silane-functionalized polydimethylsiloxanes with different chain lengths and functionality patterns, and polyethers and ethers with different ethylene and propylene oxide content (Fig. 20.22) [52, 54]. Several ionic [H2(PtCl6)] and neutral [(//-Cl)2 PtCl- (cyclohexene) 2] platinum catalysts (Table 20.9) as well as ionic liquids [1-butyl-4-methylpyridinium tetrafluoroborate (la), l-butyl-3-methylpyridinium chloride (lb), 1,2,3-trimethylimidazolium methylsulfate (2), and TEGOl IL K5MS (3)] were evaluated (Fig. 20.22). 

Dispersion (styrene aery late/aery late/ vina-ethylen-copolymere/VeoVa) Silicone (functionalized Polydimethylsiloxane)... 

PureVision is a copolymer of tris-(trimethylsiloxy)-silyl-propylvinyl carbamate (TRIS-VC), N-vinylpyrrolidone, a vinyl carbonate functional polydimethylsiloxane (PDMS) macromer, and a vinyl carbamate derivative of alanine. Eor more information, see Nicolson, P. C. Vogt, J. Biomaterials 2001, 22, 3273. 

Polymerization Procedure. All polymerizations were conducted in one ounce bottles under an argon atmosphere either in bulk or using benzene as a solvent to minimize chain transfer reactions. A typical reaction mixture contained 10 ml benzene that had been distilled from CaH2, copper octanoate (0.1 g, 2.86 x lO mole), pyridine (0.5g), triphenylphosphine (0.3g, 1.14 x 10 mole), triethylamine (O.lg, 1 x 10 mole), monomer (- 5 ml) and aldehyde-functional polydimethylsiloxane (0.4 - 2.34 g, 3.1 x lO" mole of aldehyde groups). After being heated at 70 C for 21 hr., the reaction mixtures were cooled to room temperature, diluted with benzene, and added to methanol to pre-... 

The most common polyester-modified polysiloxanes [61] that are used in the coatings industry contain a polyester based on e-caprolactone. It is polymerized on a hydroxy functional polydimethylsiloxane with 7-50 silox-ane units and 1-8 hydorxyl groups. The structural diversity of the siloxane backbone is the same as described for the polyether-modified siloxanes. 

Scheme 3.9 Synthesis of graft copolymers via side chain dithiocarbamate functionalized polydimethylsiloxane as macrophotoiniferter.

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