Propyl silicone

Propyl silicon trichloride is formed by the action of propyl magnesium bromide on silicon tetrachloride, and is a clear, colourless liquid, B.pt. 128° to 125° C. In preparing the chloride all traces of moisture must be absent. It has a penetrating odour and fumes in the air. By allowing the liquid to drop into ice-water, the acid, PrSiO. OH, is obtained, and with anhydrous alcohol the trichloride gives silicon propyl triethyi ester, PrSi(OEt)3. 

Fig. 5. Swelling of silicone rubber by solvents (493). A, fluorosilicones (methyl trifluoro-propyl silicones) B, dimethylsUicone C, methyl(phenyl)silicone.

Compounds containing a (CH2)3 linkage to the POSS core have become more widely studied than many of the alkyl derivatives because of their ready preparation and because the propyl arm is the shortest linker that usually prevents the reactivity of functional groups being enhanced by the nearby silicon... 

A silica gel containing 3-imidazole propyl groups bonded to surface atoms of silicon has been prepared (253), and was treated 254) with a solution of Fe(TPP)L2, where L = py or pip, where upon the iron(II) porphyrin became attached to the imidazole groups on the surface of the gel,... 

The class of 3-silyl-substituted reagents provides, upon addition with aldehydes, allylic silanes that offer many options for further derivatization. Oxidative processes are described in previous sections (see the sections on Preparation of 1,2-Diols and 1,4-Diols). If the appropriate silicon substituents are chosen, formal [3+2] cycloadditions with aldehydes can be promoted under Lewis acid catalysis. For example, the mismatched addition of the Z-3-propyl-3-benzhydryldimethyl allylsilane 183 to an a-benzyloxy aldehyde proceeds with low diastereofacial selectivity in favor of product 184 however, after protection of the secondary alcohol, an efficient [3+2] annulation provides the polysubsubstituted furan 185 in good yield and acceptable stereoselectivity (Scheme 24). ° The latter is brought forward to a tricyclic unit found in the antitumor natural product angelmicin B. 

The first surface-initiated enzymatic polymerization reported was the synthesis of amylose brushes on planar and spherical surfaces [145]. For this, silica or silicone surfaces were modified with self-assembled monolayers of (3 amino-propyl)trimethoxysilane or chlorodimethylsilane, respectively. To these functionalities, oligosaccharides were added via (a) reductive amidation of the oligosaccharides to surface-bound amines, (b) conversion of the oiigosaccharide to the according aldonic acid lactone and reaction with surface bound amines, and (c) incorporation... 

Experiments like those described above have been performed to evaluate sodium ion barrier properties of Hitachi PIQ and DuPont PI 2540 polyimide films. Also included in the comparison were silicon nitride coatings plasma deposited in both tensile and compressive stress modes. The structure of the samples is illustrated in Figure 9. N-type, (111) oriented silicon substrates were cleaned and oxidized in dry oxygen ambient at 1100°C to form a 1060 A Si02 film. Wafers intended for polyimide characterization were coated with an organic silane film (gamma glycidal amino propyl trimethoxysilane) to promote adhesion of the polyimide to the oxide surface. The polyimide resins were spun onto the wafers at speeds to produce final... 

Optical fibres need to be free of impurities such as transition metal ions (see Chapter 8) and conventional methods of preparing silica glasses are inadequate. The sol-gel process is one way of forming fibres of sufficient purity (chemical vapour deposition. Section 3.7, is another). These processes use volatile compounds of silicon which are more easily purified, for example by fractional distillation, than silica. It is possible to produce silica fibres using a method similar to that studied in the nineteenth century, but with the geldrying time reduced from a year to a few days. Liquid silicon alkoxide (Si(OR)4), where R is methyl, ethyl, or propyl, is hydrolysed by mixing with water. 

The formation of novel silicon-rich synthetic zeolites has been facilitated by the use of templates, such as large quaternary ammonium cations instead of Na+. For instance, the tetramethylammonium cation, [(CH3)4N], is used in the synthesis of ZK-4. The aluminosilicate framework condenses around this large cation, which can subsequently be removed by chemical or thermal decomposition. ZSM-5 is produced in a similar way using the tetra-.n-propyl ammonium ion. Only a limited number of large cations can fit into the zeolite framework, and this severely reduces the number of [AIO4] tetrahedra that can be present, producing a silicon-rich structure. 

Flotation - [AMINES - FATTY AMINES] (Vol 2) - [FLOTATION] (Vol 11) - [FOAMS] (Vol 11) - [METALLURGY-SURVEY] (Vol 16) -dye water effluent treatment [DYES, ENVIRONMENTAL CHEMISTRY] (Vol 8) -isopropyl xanthates for [PROPYL ALCOHOLS - ISOPROPYL ALCOHOL] (Vol 20) -of lead ore [LEAD] (Vol 15) -formica [MICA] (Vol 16) -m paper recycling [RECYCLING - PAPER] (Vol 21) -ofpotassium chlonde [POTASSIUM COMPOUNDS] (Vol 19) -silicates for [SILICON COMPOUNDS - SYNTHETIC INORGANIC SILICATES] (Vol 22) -use of copper composition [COPPER COMPOUNDS] (Vol 7) -usmgSCFs [SUPERCRITICAL FLUIDS] (Vol 23)... 

Aminopropylsilane is known to deposit with some amine groups oriented towards the substrate surface the conformation can be that of a zwitter ion, with the silicon and nitrogen atoms next to the substrate with the propyl chain outermost [23], or inverted, with the nitrogen next to the substrate and the silicon atom outermost [24], Either orientation will produce a peak in the N Is envelope... 

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