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Determination of Santonox

Polymer (5 g) is weighed accurately into a 500 ml round-bottomed flask. Toluene (65 ml) is added and then heated on a boiling water bath for 90 minutes using a reflux condenser. [Pg.243]

The flask is removed from the water bath and 85 ml of absolute ethanol is immediately poured down the condenser to precipitate the dissolved PE from the hot toluene solution. [Pg.243]

After cooling to room temperature, the condenser is removed, the flask is stoppered and shaken well. The solution is filtered through a No.42 Whatman filter paper into a 250 ml beaker. The flask and residue are washed with a further 100 ml of ethanol. [Pg.244]

The toluene/ethanol solution is evaporated almost to dryness on a boiling water bath with the aid of a stream of nitrogen and finally to dryness using only the nitrogen stream. If more polymer is precipitated during the evaporation, the solution is refiltered into a smaller beaker. The residue is washed into a 2 ml volumetric flask with chloroform and diluted to the mark. [Pg.244]

The extract is applied to a thin-layer plate and the chromatogram developed. The concentration of Santonox R in the PE is estimated by visually comparing the intensity of the spot obtained with corresponding spots from known quantities of Santonox R. [Pg.244]


METHOD 3 - DETERMINATION OF SANTONOX R PHENOLIC ANTIOXIDANT IN POLYETHYLENE. 2,2 -DIPYRIDYL SPECTROPHOTO-METRIC METHOD. ... [Pg.169]

A method for the determination of various types of antioxidants in polyethylene as exemplified by the determination of Santonox R phenolic antioxidant, (Note 1). [Pg.169]

Determination of Santonox R phenolic antioxidant in polyethylene. 2,2 - dipyridyl spectrophotometric method... [Pg.506]

Applications Shake-flask extraction nowadays finds only limited application in polymer/additive analysis. Carlson et al. [108] used this technique to extract antioxidants from rubber vulcanisates for identification purposes (NMR, IR, MS). Wrist-action shaking at room temperature was also used as the sample preparation step for the UV and IR determination of Ionol CP, Santonox R and oleamide extracted from pelletised polyethylene using different solvents [78]. BHT could be extracted in 98 % yield from powdered PP by shaking at room temperature for 30 min with carbon disulfide. [Pg.66]

Fig. 2 Residual antioxidant content (%) of Santonox R in PE determined by HPLC (extraction by MAE), plotted versus the corresponding OIT values, for samples aged in oxygen-free water at 90 °C. owned by the first author [46]... Fig. 2 Residual antioxidant content (%) of Santonox R in PE determined by HPLC (extraction by MAE), plotted versus the corresponding OIT values, for samples aged in oxygen-free water at 90 °C. owned by the first author [46]...
Spell and Eddy [58] have described IR spectroscopic procedures for the determination of up to 500 ppm of various additives in PE pellets following solvent extraction of additives at room temperature. They showed that lonol (2,6-di- -butyl-p-cresol) and Santonox R... [Pg.93]

Straightforward UV spectroscopy is liable to be in error because of interference by other highly absorbing impurities that may be present in the sample [59-62], Interference by such impurities in direct UV spectroscopy has been overcome or minimised by selective solvent extraction or by chromatography [60], However, within prescribed limits UV spectroscopy is of use and, as an example, procedures are described next for the determination of lonol (2,6-di- e -butyl-p-cresol) and of Santonox R (4,4"-thio-bis-6-terUbutyl-m-cresol) in polyolefins [63-66],... [Pg.96]

The oxidation is followed by reaction of the ferrous iron produced, with 2, 2 -dipyridyl to form a coloured complex, the intensity of which is proportional to the concentration of antioxidant present. The procedure has been applied to various phenolic and amine type antioxidants, namely, Succanox 18, BHT, lonol (2,6-di-tert-butyl-p-cresol), and Nonox Cl (N-N-di- 3-napthyl-p-phenylenediamine). A typical application of the procedure is given next, namely to the determination of down to 0.01% of Santonox R in PE. As the Metcalfe and Tomlinson [5] procedure determines Santonox R only in its reduced form, it does not include any Santonox R which may be present in the oxidised form in the original polymer, for example produced by atmospheric oxidation of the additive during polymer processing at elevated temperatures. Total reduced plus oxidised Santonox R can be determined by UV spectroscopic procedures. [Pg.105]

Campbell and Wise [2] applied column chromatography to the determination of known phenolic antioxidants in polyethylene (PE). This method is applicable to the analysis of mixtures of Santowhite powder (4, 4"-butylidene-bis-(6- er -butyl-w-cresol) with BHT (2,6-di-ter -butyl-p-cresol) and mixtures of Santonox R (4, 4 -thio-bis-(6-fert-butyl-m-... [Pg.141]

HPLC of polymer extracts has been used to determine dilauryl dithiopropionate, Irganox 1076 and distearyl-dithiopropionate in polyolefins [18], amine antioxidants and antiozonates in rubbers [16], Irganox 1076, Irganox 1010 and BHT in PE [19] and miscellaneous antioxidants, light stabilisers in polyolefins [20,21] and Santonox R, Ethanox 736, CAO-5, Irganox 1035, Irganox 259 and Topanol [22] in polyolefins and also the determination of antioxidants and accelerators in vulcanised rubber formulations [23-25]. [Pg.152]

Crompton [59] has described a simple direct thin-layer method for the determination of UV 531 ultraviolet stabiliser in hot toluene extracts of HDPE. Interference was encountered from a number of additives, namely, dilauryl thiodipropionate, lonox 330, lonol CP, Topanol CA, Santonox R and Polygard. [Pg.248]

Spell and Eddy [3] described infrared (IR) spectroscopic procedures for the determination of up to 500 ppm of various additives in polyethylene (PE) pellets following solvent extraction of the additives at room temperature. They showed lonol (2,6-di-ter -butyl-p-cresol) and Santonox R (4,4 -thio-bis(6-ter -butyl- /-cresol)) are extracted quantitatively from PE pellets by carbon disulfide in 2-3 hours and by isooctane in 50-75 hours. The carbon disulfide extract is suitable for scanning in the IR region between 7.8 and 9.3 (xm, while the isooctane extract is suitable for scanning in the UV region between 250 and 350 nm. [Pg.229]

Aromatic amines and phenols are among the few classes of compounds in which a large proportion of them exhibit useful fluorescence. Parker and Barnes [21] found that in solvent extracts of rubbers the strong absorption by pine tar and other constituents masks the absorption spectra of phenylnaphthylamines, whereas the fluorescence spectra of these amines are sufficiently unaffected for them to be determined directly in the unmodified extract by the fluorescence method. In a later paper Parker [22] discussed the possibility of using phosphorescence techniques for determining phenylnaphthylamines. Drushel and Sommers [7] have discussed the determination of Age Rite D (polymeric dihydroxy quinone) and phenyl-2-naphthylamine in polymer films by fluorescence methods and Santonox R and phenyl-2-naphthylamine by phosphorescence methods. [Pg.233]

A good example of an application of the van t Hoff calorimetric purity method is the determination of purity of 4,4 -thiobis(3-methyl-6-rm-butylphenol), a commercial antioxidant, with the trade name Santonox R and a molecular mass of 358g/mol. This type of phenolic antioxidant is used to prolong the life of polyolefins exposed to oxygen. Two comparative melting scans of different lots of Santonox R revealed a startling difference in melting behavior as shown in Fig. 2.11 (Bair 1997). [Pg.39]

An early report on the direct determination of stabilisers in pressed polymer films by UV spectrophotometry is due to Drushel et al [13]. The determination of a variety of additives (Santonox R, lonol, lonox 330, CAO-5, CAO-6, DPPD, Polygard, Topanol) in the 0.002-1.0% range in ten mils thick... [Pg.6]

In a very early report of direct determination of stabilisers in polymers by luminescence techniques by Drushel et al. [13] the fluorescence of EPR/Age Rite D (trimethyldihydroquinoline) and of EPR/Santonox R were examined. Lack of interference by other polymer additives and polymerisation catalyst residues was emphasised. Age Rite D concentrations can be measured directly in pressed EPR films (<0.01 cm thickness) by fluorescence at levels below 0.1-0.2 wt.% in order to prevent concentration quenching. In the fluorescence emission spectra of Irgafos 168 the fluorescence quantum yield of the phosphate is much greater than that of the phosphite [516]. This difference enables quantification of the phosphate concentration. Although direct quantitative determination of UV stabilisers in extruded polyolefins by means of fluorescence spectroscopy (ex, 370 nm em, 390-550 nm) has been described [517], this is certainly not a universally applicable technique (being additive and matrix dependent). The effects of additives (AOs and cross-linking agent by-products) on electroluminescence... [Pg.79]

Since the determination of inhibitors in polymers by Drushel et al. [13] little information has been added to the literature on the quantitative aspects of the direct examination of polymer films by phosphorescence spectroscopy. These authors examined phosphorescence (at liquid-nitrogen temperature) of thin EPR films containing Santonox R (2,2 -di-methyl-5,5 -di-r -butyl-4,4 -dihydroxydiphenyl sulfide) and V-phenyl-2-naphthyl-amine (PBN). The rather intense phosphorescence of PBN may be used to advantage when other additives interfere in the UV absorption method. As to quantitative phosphorescence analysis, several factors, e.g. film thickness, concentration quenching, and background absorption, etc., affect the linearity of the analytical working curves and precision of the measurements [13]. The reliability of a correlation between stabiliser concentration in the film and phosphorescence intensity at 77 K is also influenced by the degree of crystallinity [544]. [Pg.82]

N = Weight (g) of Santonox R in 10 cm polyethylene extract obtained by referring determined optical density to the calibration graph. [Pg.172]

Santonox R is extracted from a finely ground sample with boiling cyclohexane. The extract is then shaken with aqueous sodium hydroxide. Santonox R forms a sodium salt in the alkali layer. This layer is then examined on an ultraviolet spectrophotometer. The base line absorbance is calculated and referred to a previously prepared calibrated graph relating weight of Santonox R to base line absorbance. lonol does not interfere in the determination... [Pg.178]

A thin layer chromatographic method for the determination of down to 0.002% of Santonox R in polyolefins. [Pg.184]

Thus the weight % of Santonox R in high density polyethylene = 2/5 x the level of Santonox R present in the 2 ml chloroform solution (as determined by thin-layer chromatography in % w/v). [Pg.186]

Ultraviolet spectroscopy is applicable to the determination of phenolic antioxidants in aqueous and alcoholic simulant liquids and also to one of the fatty simulants, liquid paraffin, recommended by the British Plastics Federation (BPF). Full details of the procedure, which is capable of determining down to 1-2 ppm of Santonox R in the simulent liquids, is given next. With the exception of the 5% citric acid simulent, errors are generally of the order of less than 10% of the determined concentration. Typical recoveries of Santonox R in the 5% citric acid extractant were between 15% of the expected result. [Pg.43]

Table 5.1 gives the formulation of a polyethylene and a polystyrene used in some Uvitex OB extractability studies. In addition to the ultraviolet stabiliser, liquids obtained in extractability tests carried out on these plastics would contain various other substances, some of which are ultraviolet absorbers and which may be present in the extractant at higher concentrations than Uvitex OB. In this case the polymer also contained Santonox R, Wingstay T, phenolic antioxidant and styrene monomer. The presence of such ultraviolet absorbing substances in the extractant will interfere in the determination of Uvitex OB at 378 nm. In applying spectroscopic methods of analysis to extractants, consideration must always be given to the possibility of interference by any polymer additives present other than that which one is required to determine. [Pg.75]

Interference by Santonox R in the determination of lonol CP at 276 nm was overcome by means of a preliminary separation on a column of 100-200 mesh silica gel (containing 4% water). To isolate total additives from the aqueous extraction liquid it was saturated with sodium chloride and then extracted with diethyl ether, followed by extraction with chloroform. The chloroform was dried with sodium sulfate and... [Pg.156]

A new method is described for the quantitative determination of some sulphur-containing antioxidants in PE. The polymer matrix is dissolved in hot n-heptane/ isopropyl alcohol, 97/3 v/v at 160 deg.C under elevated pressure (0.33 MPa) and precipitated by cooling. The solution is injected directly into a normal-phase silica gel column flushed with the same solvent as used for the dissolution of the polymer. This method gives high recovery of the antioxidants, good repeatability of the analysis and a low detection limit of 0.011 mg 4,4 -thiobis(3-methyl-6-tert-butylphenol) (Santonox R) /I g PE 0.074 mg ditetradecyl-beta,beta -thiodipropionate (Chimox 14) / 1... [Pg.124]


See other pages where Determination of Santonox is mentioned: [Pg.229]    [Pg.243]    [Pg.229]    [Pg.243]    [Pg.249]    [Pg.310]    [Pg.288]    [Pg.132]    [Pg.135]    [Pg.142]    [Pg.244]    [Pg.21]    [Pg.172]    [Pg.383]    [Pg.5]    [Pg.7]    [Pg.75]    [Pg.158]   


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