Santonox R In Polyolefins

A representative sample was ground in the Apex Mill, About 1 gram of the sample was weighed into a 100 ml round-bottomed flask and cyclohexane (20 ml) was added, A condenser was fitted to the flask and the cyclohexane was allowed to reflux on a water bath for 1 hour. The condenser was washed with 20 ml cyclohexane, the flask was removed from the bath, cooled to room temperature and then shaken well. The solution was filtered through a No, 802 filter paper into a 100 ml separating funnel. The filter 

The base line absorbance was plotted against the concentration of Santonox R in mg/100 ml. 

Ruddle and Wilson [66] have described a UV spectroscopic method for the characterisation of phenolic stabilisers in solvent extracts of polymer compositions. 

These workers point out that usually the additive must be separated in a pure state from co-extracted additives usually by thin-layer chromatography (TLC) and then identified by measurement of the UV, IR, nuclear magnetic resonance (NMR) and mass spectra of the compound. This full treatment is required only for new stabilisers - for a characterisation of well known compounds the simplest method is by direct comparison of the UV absorption spectra with those of a series of known stabilisers. For some compounds this will probably be sufficient, but many substituted phenols have similar spectra, and for three of the most frequently used antioxidants the UV spectra are identical. Topanol OC, lonox 330 and Binox M (see Table 2.11 for their chemical constitution) in ethanolic solution all have = 277 nm, with a shoulder at 282 nm. To extend this procedure Ruddle andWilson [66] prepared the spectra of alkaline solutions of the phenols, which were then measured either directly against a solvent blank or as difference spectra measured against the neutral solution. This still gives almost identical spectra for the three compounds mentioned previously. 

Ruddle and Wilson [66] developed two further stages in this procedure for extending the use of UV spectrophotometry in the characterisation of these compounds. They consist of (a) measuring the UV absorption spectrum of the stabiliser solution after reaction with solid nickel peroxide and (b) remeasuring it after making the reaction products alkaline. Cook [67] obtained the substituted stilbene quinone after 

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Straightforward UV spectroscopy is liable to be in error owing to interference by other highly absorbing impurities that may be present in the sample [11-13]. Interference by such impurities in direct UV spectroscopy has been overcome or minimised by selective solvent extraction or by chromatography. Flowever, within prescribed limits UV spectroscopy is of use and, as an example [14-18], procedures have been developed for the determination of lonol and of Santonox R in polyolefins. 

A thin layer chromatographic method for the determination of down to 0.002% of Santonox R in polyolefins. 

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