SILICON COPOLYMER

Mazurek, M. Silicone Copolymer Networks and Interpenetrating Networks. In Silicon-Containing Polymers. The Science and Technology of Their Synthesis and Applications-, Jones, R. G., Ando, W., Chojnowski, J., Eds. Kluwer Dordrecht, 2000 pp 113-137. 

Keohan FL, Swint SA, Buese MA (1991) Selective degradation of silicone copolymers and networks. J Polym Sci Part A Polym Chem 29 303... 

A significant amount of information regarding the uses of silicone surfactants is still found primarily in the patent art, but the major applications have recently been reviewed in journals. Silicone (or siloxane) surfactants are also called silicone polyethers (SPEs), polyalkylene oxide silicone copolymers, silicone poly(oxyalkylene) copolymers and silicone glycols. The International Cosmetic Ingredient Nomenclature and the Cosmetic, Toiletry and Fragrance Association (CTFA) adopted name is dimethicone copolyol. 

The most common polymeric silicone surfactants are based on polyoxyalkylene groups. The structures of graft-type (rake-type) and ABA structures are illustrated in Figures 6.17 and 6.18. It should be noted that there are many possible variants of these basic structures. The actual structure of graft-type silicone copolymers is a random copolymer of m and n rather than the blocky structure suggested by the diagram. 

Fig. 7. Storage modulus (A), loss modulus (0) and tanS (O) as a function of temperature for unfilled (A) and filled silicon copolymer containing 12 vol% (30 phr) (B) and 17 vol% (46 phr) (C) of Aerosal (380 m g ) [49] the torsion widi the amplitude of 0.05% was measured for a rectangular sample at 1. 6 Hz on Rheometrics, INC, RMS 800 samples were cured with 2 wt. % dicumyl peroxide...

Surfactants. Silicone surfactants lower the surface tension and emulsify incompatible ingredients. Copolymers of polydimethylsiloxane and polyoxyalkylene were the originally used surfactants. Surfactants with Si—O—C bonds are hydrolysable, but those with only a Si—C bond are non-hydrolysable. Several non-hydrolysable alkyl pendant silicone copolymers are used as surfactants for specific formulations (Seymour, 1992). 

Silicone copolymer and SIS rubber (i.e., with a high lipophilic additive, paraffin) have a higher lipophilicity than acrylic copolymer. Hence, both bases give a much lower drug solubility than common acrylic copolymers. 

As demonstrated, SIS rubber and silicone copolymers are relatively inert drugs thus little interaction happens with these adhesives. But the acrylic copolymer easily causes interactions with drugs when polar functional groups exist in the copolymer. The extent of the interaction of drugs with the copolymer significantly influences the diffusion of drugs in the PSA matrix, and even affects drug stability. 

Keywords monofunctional silicone fluids, silicone copolymers... 

Silicone copolymers containing Wacker macromonomers may be used beneficially in all plications and industries where otiier hybrid materials from silicones and organic monomers are... 

The following list - though not comprehensive - gives an overview of potential implications for monofrmctional fluids and silicone copolymers. 

Summary Wacker Specialties succeeded in developing proprietary processes to manufacture silicone copolymers. The problems of combining silicone and vinyl polymers were overcome. So, for example, silicone-modified polyvinyl acetate, silicone-modified polyvinyl alcohol, and silicone-modified polyvinyl acetal were obtained on a laboratory or pilot plant scale. These products, having very interesting properties, could be advantageously used for various applications. 

Silicone Copolymers for Coatings, Cosmetics, and Textile and Fabric Care 711... 

The silicone content of the polyvinyl acetate-silicone copolymers can be varied by up to 50% or more. The glass transition temperature Tg is usually in the range between 10 and 35 °C. Typical molecular weights are between 10 000 and approximately 80 000 g/mol. 

Fig. 2. Rheological properties of a vinyl acetate-silicone copolymer (20 wt% silicone) in a molten state.

Saponified Polyvinyl Acetate-Silicone Copolymers (Silicone-Modified Polyvinyl Alcohols) [1]... 

Wacker Specialties saponified polyvinyl acetate-silicone copolymers (silicone-modified polyvinyl alcohols) have the following properties ... 

With these properties, saponified polyvinyl acetate-silicone copolymers can be used in cosmetic formulations (e.g., for hair and skin care) such as shampoos, lotions, and cremes or as a fabric care agent. 

Keywords silicone copolymers, surface analytics, atomic force microscopy... 

Summary Silicone copolymers are hybrid matmals with varying phase separation levels. The polymers themselves as well as surfaces formed by these copolymers were analyzed by a variety of polymer and surface characterization methods. Atomic force microscopy was found to be especially suitable for analysis of thin polymer films. Both surface and bulk properties are dominated by the domain size and the silicone content. 

Surface analysis (XPS, SIMS) of silicone copolymer films as a function of their thickness. Surprisingly, thinner films show a higher relative siloxane concentration at their surface than thicker ones. As expected, the silicon metal concentration measured by secondary ion mass spectrometry is higher because of the lower depth profiled by the method. 

Analytical characterization of hybrid silicone copolymer systems shows distinct phase separation patterns depending on the level of silicone concentration in the copolymer. Copolymers with a siloxane content of 10 wt% or lower do not show any domains. 

Auxiliary blowing agent - Fluorocarbon Catalyst - Organotin salt Catalyst - Tertiary amines Surfactant - Silicone copolymer... 

C linkages and are hydrolytically unstable others do not contain a silicone-carbon bond and are stable. In general, higher-viscosity silicone copolymers are more efficient and wiU provide foams with finer cell structures. Surfactants are used at the 0.5% to 1% level in rigid urethane foams. With too little silicone foam, cell structure is large. Too much silicone does not affect the foam properties, but is wasteful. There is no known health hazard with the use of silicones (20). 

Poly(dimethylsiloxane-co-oxyethylene-co-oxypropylene) is used as a surfactant, dispersant, and wetting agent, while poly[bisphenol A bis(oxyranylmethyl) ether]-co-poly(dimethylsiloxane) is used as an epoxy resin. More complicated silicone copolymers also were synthesized such as the silicone polyetherimide shown below ... 

Silicone Copolymers, Block Copolymers and Graft Copolymers... 

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