Polymers colour-matched

Compounding as a separate industry was originally devoted mainly to the addition of colouring, especially for special colour matches. This gradually developed to skill in short-run production, with high efficiency in distribution, to meet the demand from plastics processors for small volumes of special grades. Many independent compounders now operate under franchise from polymer producers, while also marketing their own formulations. 

Today the principal outlets are knife handles, table-tennis balls and spectacle frames. The continued use in knife handles is due to the pleasant appearance and the ability of the material to after-shrink around the extension of the blade. Table-tennis balls continue to be made from celluloid since it has been difficult to match the bounce and handle of the celluloid ball, the type originally used, with balls fabricated from newer polymers. Even here celluloid is now meeting the challenge of synthetic polymers. Spectacle frames are still of interest because of the attractive colour. There are, however, restrictions to their use for this application in certain countries and cellulose acetate is often preferred. 

Differences between the ingredients in a formulation may be essentially of a chemical nature, but also may be physical (such as the ranges of particle sizes)—and quite often both chemical and physical variations are found in practice. In order to match a particular material consistently it is not sufficient merely to know even the precise formulation in terms of polymer, plasticizer, heat stabilizer, filler, anti-static agent, colour, and so forth each of the components in the formulation must be supplied consistently to a tight... 

Rhodium complex was loaded onto the quatemised polymer support by the reaction with [Rh(CO)2I]2 in hexane (Eq 2). The resulting polymer beads or films showed the characteristic yellow colour of [Rh(CO)2I2] . An infrared spectrum of the powdered beads (KBr disk) showed two weak v(CO) absorptions of similar intensity at 2056 and 1984 cm 1, consistent with the presence of the cis-dicarbonyl complex, [Rh(CO)2I2]" (2059, 1988 cm 1 in CH2C12). Spectra of a much higher quality and intensity were obtained from polymer films loaded with rhodium complex. These observations of polymer supported [Rh(CO),I,r match those reported in the original study of Drago et al. 

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