Slip agents, determination

LDPE or HDPE extracts has been determined colorimet-rically at 430 nm by oxidation with H202 in the presence of H2S04 [66]. p-Phenylenediamine derivatives such as Flexzone 3C, used as antiozonants in rubber products, have been determined colorimetrically after oxidation to the corresponding Wurster salts [67]. A wide range of amine AOs in polyolefins has been determined by the p-nitroaniline spectrophotometric procedure [68]. Monoethanolamine (MEA) in a slip agent in PE film has been determined as a salicylaldehyde derivative by spectrophotometric quantification at 385 nm [69]. Table 5.6 contains additional examples of the use of 1JV/VIS spectrophotometry for the determination of additives in polymers. 

But many fadors determine the right concenttation for a film. If anything, slip agents are often added at too high a concenttation. This causes an excessive... 

The effectivity of a lubricant or slip agent is determined by its affinity to the polymer. Lubricants well dissolved by the polymer are enriched in the outer zones of the flow units. The flow units swell and liquify with the already liquid phase. Such lubricants act as internal lubricants, that is, they are a kind of plasticizer. 

Various workers have reviewed the application of IR spectroscopy to the determination of additives [16, 17, 18]. Other recent applications of IR spectroscopy include the determination of slip agents in PE [19], ethyl acetate and ethanol in HDPE [20], stearic acid in polystyrene (PS) [21], talc, antimony trioxide and decabromophenylether flame retardants in polyvinyl chloride (PVC) [22-24], mould release agents [25] and binders in aged paint film [26]. 

Semi-volatile and non-volatile additives in polycarbonate (PC) and PC/polybutylene terephthalate blends have been determined without chromatographic separation using a particle beam interface for direct introduction of the samples into the mass spectrometer. Antioxidants, UV stabilisers, flame retardants, and slip agents were among the additives determined. The key to this approach was the speed and simplicity of identifying multiple additives in a single matrix [134]. 

Several analytical methods were developed using liquid chromatography to determine concentrations of slip agents in polyethylene and pol3q)ropylene. ... 

The SNCR reaction has been studied extensively, and the detailed chemistry is fairly well established. Use the provided chemical kinetic model for SNCR (SNCR.mec [276]) together with a plug-flow code to assess the potential of SNCR in reducing NO in the municipal solid waste (MSW) facility, based on the available technical information. Determine the preferred agent injection location and the optimum NH3/NO ratio, with the restriction that the NH3 slip must not exceed 15 ppm. 

Anti-blocking agents reduce the tendency of layers of film to stick together in tightly wound reels or stacked sheets. The use of an anti-blocking agent may affect the performance of other additives (such as slip or anti-static). It is therefore important that a full evaluation is carried out to determine the suitability of combinations of additives. 

Friction. The coefficient of friction (COE) is a measure of the friction forces between two surfaces. It characterizes a film s frictional behavior. The COE of a surface is determined by the surface adhesivity (surface tension and crystallinity), additives (slip, pigment and antiblock agents), and surface finish. Cases in which the material s COE values require careful consideration include film passing over free-running rolls bag form-... 

Due to their partial incompatibility, which determines effectiveness, a certain degree of slip effect, which may cause feed difficulties during extrusion, has to be taken into account when processing TPO with antistatic agents. The addition of small amounts... 

Polymer formulations usually include one or more compounds such as antioxidants, secondary antioxidants, antistatic additives, light stabilisers, lubricants, plasticisers, stabilisers, slip and antiblock agents. In addition, the polymer and hence the extractant liquid might contain other substances not deliberately added such as unreacted monomers, residual polymerisation solvents and catalysts. The result is that practical extractants from such plastics can contain very low concentrations of several very different types of substances which may or may not mutually interfere with each other during these subsequent analyses and one or more of which it may be necessary to determine. 

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