Santonox

In the presence of carbon black the phenols and phenol/DLTP combinations are much less effective whilst some phenolic sulphides (e.g. Santonox) show positive synergism with carbon black. Flowever, in general terms the phenol systems tend to be reduced to about the same levels as to those to which the phenol sulphide systems are raised. Some typical figures are given in Table 10.8. 

A series of polyamine disulphides (polyaniline disulphide, polyamine disulphide, and polyparaphenylenedi-amine disulphide) represent effective thermostabilizers of cured polyethylene, and provide a decrease in gel fraction 2.5-3 times as large as that in case of inhibited thermal destruction. Stabilizers of normal polyethylene (Neozone D , Santonox R ) are inefficient as stabilizers of cured polyethylene, these substances decompose and even initiate thermal destruction of cured polyethylene. 

The extraction time has been observed to vary linearly with polymer density and decreases with smaller particle size [78,79]. The extraction time varies considerably for different solvents and additives. Small particle sizes are often essential to complete the extraction in reasonable times, and the solvents must be carefully selected to swell the polymer to dissolve the additives quantitatively. By powdering PP to 50 mesh size, 98 % extraction of BHT can be achieved by shaking at room temperature for 30 min with carbon disulfide. With isooctane the same recovery requires 125 min Santonox is extractable quantitatively with iso-octane only after 2000mm. The choice of solvent significantly influences the duration of the extraction. For example talc filled PP can be extracted in 72 h with chloroform, but needs only 24 h with THF [80]. pH plays a role in extracting weakly acidic and basic organic solutes, but is rarely addressed explicitly as a parameter. 

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. 

The pressurised dissolution/cooling procedure of Macko el al. [490], which uses a UV-transparent low-boiling point solvent, is fast and simple as no additional evaporation of the solvent, preconcentration or redissolution of the additive is necessary. Macko el al. [491] have given an extensive listing of HPLC analyses of aromatic antioxidants and UVAs which can be separated with n-heptane and n-hexane as the main component of the mobile phase. The method was also used for HPLC quantification of thioether antioxidants (Santonox R, Chimox 14 and Irganox PS 802) in MDPE [612],... 

Squirrell [469] has mentioned TLC of commercial polymer additives (Topanol OC, DLTDP, DSTDP, Ionox 330, Irganox 259/288/1010/1076, Nonox WSP, Polygard, Santonox R, Tinuvin 326/327/328, Topanol CA, UV531, Hoechst D 55, oleamide, erucamide, Ethomeen T12, stearic acid, and others). A TLC procedure has also been described for identification of... 

Various additives in PE (Santonox, Nonox DPPD, Neozone A, Ionol and Agerite White) were determined by conventional TLC [507]. Other additives in PE, studied by means of TLC, were Tinuvin P 120/326/327/770, Cyasorb UV531, Anti UV P (2-hydroxy-4-n-octyloxybenzophenone), Irganox 1076, Sanduvor EPU, AO-4 and Dastib 242/263 [508], TLC has also been used in the analysis of additives in polyurethanes [509,510] as well as of slip additives (ethoxylated amines and amides) in HDPE extracts... 

Applications Open-column chromatography was used for polymer/additive analysis mainly in the 1950-1970 period (cf. Vimalasiri et al. [160]). Examples are the application of CC to styrene-butadiene copoly-mer/(additives, low-MW compounds) [530] and rubbers accelerators, antioxidants) [531]. Column chromatography of nine plasticisers in PVC with various elution solvents has been reported [44], as well as the separation of CHCI3 solvent extracts of PE/(BHT, Santonox R) on an alumina column [532]. Similarly, Santonox R and Ionol CP were easily separated using benzene and Topanol CA and dilaurylthiodipropionate using cyclohexane ethyl acetate (9 1 v/v) [533]. CC on neutral alumina has been used for the separation of antioxidants, accelerators and plasticisers in rubber extracts [534]. Column chromatography of polymer additives has been reviewed [160,375,376]. 

Infrared measurement of additive concentrations is a more complex analysis than initially expected, as some additives may undergo a variety of chemical reactions during processing, as shown by Reeder et al. [128] for the FTIR analysis of phosphites in polyolefins. Some further examples of IR work refer to PVC/metal stearates [129], and PE/Santonox R [68,130]. Klingbeil [131] has examined the decomposition of various organic peroxyesters (TBPB, TBPP, TBPA and TBPO) and a peroxidicarbonate (BOPD) as a function of pressure, temperature and solvent by means of quantitative FTIR using an optical high p, T reaction cell. 

Direct pyrolysis in the ion source of a mass spectrometer (QMS) was used to analyse PE/(dicumylperoxide, Santonox R) and PVC/DIOP [259]. In-source PyMS is an analytical tool for fast analysis of flame retardants in unknown mixtures of polymers [223, 265], Heeren and Boon [224] used in-source filament pyrolysis FTMS for high-speed, broadband screening of additives in polymeric household appliances. 

SFE-LC-MS has given unique information for the examination of polymer additives and their breakdown products [131]. Lynch et al. [46] studied PE/(Santonox R, Cyasorb UV531, Irganox 3114/1010/1076) by means of SFE-LC-TSP-MS and SFE-LC-PB-MS. This system has been shown to give less degradation in polymer... 

Structural isomer pairs Ethanox 720 and Plastanox 2246 Topanol L and Santonox R. 

I- Topanol (1,1,3-tri ter-butyl hydroxy methyl phenyl)butane) and Nonox DLTDP (di laurylthiodipropionate) 0.1 wt% in solution II- Santonox-R (4,4 -thio-bis-(6-terbutyl... 

Tenite 3310 and DFD 6040 (formerly DYNK) have been described (23). Both contain 0.05% Santonox (Monsanto Chemical Co.), a thio-bisphenolic antioxidant. 

Monsanto Santonox R 4,4 -thiobis (6-tert-butyl-w-cresol)... 

SYNS BIS(3-tert-BU1TL-4-HYDROXY-6-METHYL-PHENYL) SULFIDE BIS(4-HYDROXY-5-tert-BUTyL-2-METHYLPHENYL) sulfide DISPERSE MB-61 SANTONOX SANTOVC HITE CRYSTALS THIOALKOFEN BM 4 4,4 -THIOBIS(2-tert-BUTYL-5-METHYLPHENOL) 4,4 -THIOBIS(6-tert-BUTYL-3-METHYLPHENOL) 4,4 -THIOBIS(3-METHYL-6-tert-BUTYLPHENOL) l,l -THIOBIS(2-METHYL-4-HYDRO-XY-5-tert-BUTYLBENZENE) USAFB-15 YOSHINOX S... 

SANTOFLEX A see SAVOOO SANTOFLEX AW see SAVOOO SANTOFLEX IC see PEY500 SANTOMERSE 3 see DXW200 SANTONOX see TFC600 SANTOPHEN see PAX250... 

PE Dicumyl peroxide, Santonox Extract with methanol, concentrate (evaporative) Lichrosorb RP 18, 250 X 4.6 mm, 10 pm Methanol/water, 80/20 254 1 mL/min [1]... 

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]...

Similar results are shown in Eig. 2 for the antioxidant Santonox R aged in oxygen-free water at 90 °C [46]. 

Lichtentaler and Ranfeldt have shown that the size of the antioxidant has an impact on the extraction efficiency. They Soxhlet-extracted five phenolic antioxidants (BHT, Irganox 1010, Irganox 1076, Santonox R, lonox 330) from a PE powder with chloroform for a time between 2 and 5 h, and analyzed the extracts by both isocratic HPLC analysis in n-hexane and by gradient HPLC in -hexane DCM (0-30%) [53]. In the case of BHT, only 2 h of extraction were needed to achieve an extraction yield of 95%, whereas the larger antioxidant Irganox 1076 required a time of 3.5 h for 90% recovery, and Irganox 1010 required a time of 5 h for a yield of about 85% (Fig. 3). 

Fig. 6 HPLC chromatograms of Santonox R extracted by MAE from PE plates, un-aged and aged at different times in oxygen-free water at 90 °C. Santonox R peak at 1.6 min and internal standard peak at 7.3 min. owned by the authors...

Macko et al. [35] quantified thioether antioxidants (including Santonox R) in PE by HPLC, after extraction under pressure in an autoclave in 100 mL of n-heptane IPA (97 3 v/v). The temperature was ramped up to 160 °C over 15 min and this temperature was then held for 75 min. Only about 80% of the... 

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