Silicones modified, applications

Floyd, D. T. Jenni, K. R. Silicone Polymers, Organo-Modified (Application in Personal Care Products). In Polymeric Materials Encyclopedia, Salamone, J. C., Ed. CRC Press Boca Baton, 1996 Vol. 10, pp 7677-7688. 

Perry, R. J. Adams, M. E. TOSPEARL Silicone Resin for Industrial Applications. In Silicones and Silicone-Modified Materials-, Clarson, S. J., Fitzgerald, J. J., Owen, M. J., Smith, S. D., Eds. AGS Symposium Series 729 American Chemical Society ... 

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. 

Topcoats based on fluorocarbon resins [poly(vinylidene fluoride)] produce extremely durable coatings (life to first maintenance > 20 years under most climatic conditions) with excellent color and gloss retention. Like silicone-modified resins they are used for applications where weather resistance is required (e.g., exterior panels on buildings). Because of high prices the importance of these systems is limited. 

Since application of a wet process for copper wiring was demonstrated by the IBM group in 1997 (Andrecacos et al. 1998), applicability of the electrochemical deposition to fine structure formation has been widely recognized. Electrochemical deposition enables to prepare various types of porous silicon modified with metal as illustrated in Fig. 1. We confine the topic in this section to the wet processes here. The processes consist of electrodeposition and displacement or electroless deposition. 

Alkoxylated polysiloxanes are a relatively new class of dyebath lubricants. They have practically no substantivity for the substrate, yet combine adequate lubrication with water solubility and easy rinsability. If the silicones contain primary hydroxy groups, these can be modified by esterification, phosphation, phosphonation, sulphation, sulphonation or carboxylation. These anionic substituents confer substantivity for various substrates without losing rinsability. Anionic organic sulphates and sulphonates probably offer the best overall properties for dyebath lubricants, whilst other types can be more suitable for selected applications [464]. 

When applied to silicon, both approaches suffer from problems common to small-basis-set techniques, namely they do not treat the conduction bands accurately. They can be parametrized to yield the proper band gap, and the defect properties seem not to be extremely sensitive to this factor. These approaches can be modified into supercell or cyclic-cluster forms, although most applications to date have involved finite clusters with hydrogen terminators. 

The hydrolytic polycondensation of silicon alkoxides of general formula Si(OR)4 or R/ Si(OR)4 , where the non-reactive organofunc-tional group R acts as a network modifier, is carried out in the presence of dopant molecules resulting in the formation of highly porous, reactive organosilicates whose applications span many traditional domains of chemistry. 

Boutevin, B. Guida-Pietrasanta, F. Ratsimihety, A. Side Group Modified Polysiloxanes. In Silicon-Containing Polymers. The Science and Technology of Their Synthesis and Applications-, Jones, R. G., Ando, W., Chojnowski, J., Eds. Kluwer Dordrecht, 2000 Chapter 3, pp 79-112. 

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