PRODUCTS

TERTIARY DODECYL MERCAPTAN

Tertiary Dodecyl Mercaptan (tert-dodecyl mercaptan, TDM) is a transitional ‘existing’ substance which was discussed by the former EU PBT Working Group on a number of o c c a si on s . As a result of these discussions the substance was included in Regulation (EC) No. 465/2008 of 28th May 2008, which required industry to conduct an enhanced biodegradation test and fish bioconcentration study and submit the results by November 2009. The data were provided in January 2013. Based on the available information, TDM does not meets the Annex XIII criteria for either a ‘persistent, bioaccumulative and toxic’ (PBT) or a ‘very persistent and very bioaccumulative’ (vPvB) substance in the environment.

CAS No. : 25103-58-6
EC No. : 246-619-1

Synonyms:
TDM (Tertiary Dodecyl Mercaptan); tert-dodecanethiol; tert-Dodecyl mercaptan; TERT-DODECANETHIOL; t-Dodecanethiol; t-Dodecylmercaptan; Sulfole 120; CCRIS 6030; t-DDM; 2,3,3,4,4,5-hexamethylhexane-2-thiol; Tertiary Dodecyl Mercaptan; terc.Dodecylmerkaptan [Czech]; EINECS 246-619-1; BRN 1738382; 2,3,3,4,4,5-Hexamethyl-2-hexanethiol; terc.Dodecylmerkaptan; Tertiary-dodecanethiol (tert-dodecyl mercaptan, TDM); n-Dodecyl mercaptan; Dodecyl mercaptan; Lauryl mercaptan; Mercaptan C12; NDM; 1-Dodecanethiol; CH3(CH2)11SH; 202.40; tert-Dodecyl mercaptan; TERT-DODECANETHIOL; tert-Dodecylthiol; t-Dodecanethiol; t-Dodecylmercaptan; Sulfole 120; CCRIS 6030; t-DDM; 2,3,3,4,4,5-hexamethylhexane-2-thiol; terc.Dodecylmerkaptan [Czech]; 1,3,3,4,4,5-Hexamethyl-2-hexanethiol; 3-01-00-01794; (Beilstein Handbook Reference); I14-10461; 119147-91-0; 90501-34-1; C12H26S; 1-Dodécanethiol; 1-Dodecanthiol; Pennfloat M; TERTIARY DODECYL MERCAPTAN; Pennfloat S; dodesil; dodesil merkaptan; merkaptan; dodecil; dodecil mercaptan; dodecyl mercaptane; dodesil mercaptane; dodecyl merkaptan; dodecyl merkaptane; dodesil merkaptane;n-Dodecyl mercaptan; Dodecyl mercaptan; Lauryl mercaptan; Mercaptan C12; NDM; 1-Dodecanethiol; CH3(CH2)11SH; Tertiary Dodecyl Mercaptan; tert-Dodecyl mercaptan; TERT-DODECANETHIOL; tert-Dodecylthiol; t-Dodecanethiol; t-Dodecylmercaptan; Sulfole 120; CCRIS 6030; t-DDM; 2,3,3,4,4,5-hexamethylhexane-2-thiol; terc.Dodecylmerkaptan [Czech]; 1,3,3,4,4,5-Hexamethyl-2-hexanethiol; EINECS 246-619-1; BRN 1738382; terc.Dodecylmerkaptan; (Beilstein Handbook Reference); I14-10461; 119147-91-0; 90501-34-1; C12H26S; 1-Dodécanethiol; 1-Dodecanthiol; Pennfloat M; Pennfloat S; dodesil; dodesil merkaptan; merkaptan; dodecil; dodecil mercaptan; dodecyl mercaptane; dodesil mercaptane; dodecyl merkaptan; TDM; tdm; tert-Dodecyl mercaptan; TERT-DODECANETHIOL; t-Dodecanethiol; t-Dodecylmercaptan; Sulfole 120; CCRIS 6030; t-DDM; terc.Dodecylmerkaptan [Czech]; EINECS 246-619-1; 2,3,3,4,4,5; Hexamethyl-2-hexanethiol; 2,3,3,4,4,5-hexamethylhexane-2-thiol, Dodécyl mercaptan tertiaire

Tertiary Dodecyl Mercaptan

TDM (Tertiary Dodecyl Mercaptan) is commonly used in the manufacturing process of polymers based on butadiene and styrene (SB latex, SB rubber, ABS...)

Chemical name : tert-dodecanethiol
Common name : TDM

Properties
Density (20°C): 858 kg/m3
Viscosity (20 °C): 36 mPa.s (cP)
Flash point (closed cup): 97 °C
Vapour pressure (20°C): 0.03 mbar (hPa)
Vapour pressure (50°C): 0.8 mbar (hPa)
Refractive index (20°C): 1.461
Boiling point: 233°C
Melting point < -30°C
Decomposition temperature: 350°C

SOLUBILITY
Tertiary Dodecyl Mercaptan is not soluble in water, slightly soluble in light alcohols and soluble in styrene and most organic solvents.

In the process of manufacturing latex such as styrene-butadiene, a chain transfer agent is required. The chain transfer agent assists in the polymerization to make products of the desired molecular distribution. Previously, chlorinated compounds such as carbon tetrachloride and chloroform have been used for this application, but because of their toxicity and negative environmental effects, it is no longer a practice to employ said compounds for the manufacturing of latex used for the carpet and paper industries. Instead, use of tertiary dodecyl mercaptan (TDM) is preferred for the applications described. As a result of the world demand for latex and the magnitude of the associated industries, Tertiary dodecyl mercaptan has become a chemical of industrial significance.

From a manufacturing standpoint, Tertiary dodecyl mercaptan is a mixture of isomeric thiols produced from oligomers of propylene tetramer or sometimes, isobutylene trimer. Propylene tetramer is produced by oligomerization of propylene in the presence of a FriedelCrafts type catalyst such as sulfuric acid. Tertiary dodecyl mercaptan is produced by passing hydrogen sulfide and either propylene tetramer or isobutylene trimer over a catalyst such as boron trifluoride. Because of the fact that there are many permutations of the tetramer structure, and hence the location of the –C=C– bond, the thiol group can be located in many different positions, resulting in a product mixture of isomers with an average boiling
point range around 230°C. Recently, there has also been some increased concerns regarding to the accumulation of Tertiary dodecyl mercaptan in the environment.

The open literature contains little to no information on the analysis of Tertiary dodecyl mercaptan. This is partly due to the fact that the matrix can be quite complex. An example would be water soluble emulsion polymer, comprizing hundreds of components which can cause chromatographic interference. Also, alkyl mercaptans such as Tertiary dodecyl mercaptan are difficult to analyze due to reasons such as the alkyl chains are C8 to C15 in size and cover a wide range of boiling points, the polarity of the individual components in Tertiary dodecyl mercaptan varies with the degree of thiolation, the location of the R-SH moiety. In addition to the differences in polarity and boiling points of the Tertiary dodecyl mercaptan components, the product can also contain a fraction of relatively non-polar, non-thiolated tetramer. For the measurement of Tertiary dodecyl mercaptan, an internal method involves the use of headspace gas chromatography in combination with flame photometric detection (FPD) had been developed. The method, however, has its constraints, including competing vapour–liquid equilibrium of solutes in the sample and the lack of linear dynamic range of the FPD.

As a result, a new chromatographic method is required for raw material identification of Tertiary dodecyl mercaptan, for trend analysis, and for the monitoring of residual material in the final products.

The new chromatographic method was developed with three enablers: (i) Liquid–liquid extraction to remove Tertiary dodecyl mercaptan isomers from their respective matrices; (ii) Low thermal mass gas chromatography to deliver the flexibility of either speciation of individual sulfur compounds, or peak compression to combine individual sulfur compounds into one discreet peak with high temperature programming capability and to improves overall sample to sample throughput; (iii) Dual plasma sulfur chemiluminescence detector (DP-SCD) to offer the highest degree of selectivity for Tertiary dodecyl mercaptan isomers, equi-molar response and a respectable linear dynamic range. This report summarizes the method development and analytical results obtained.

The total sulfur approach
In the total sulfur approach, the separation power of the column is compressed by operating the column at an elevated temperature. The rationale of this approach is that because all the isomers of Tertiary dodecyl mercaptan are compressed into one discreet, Gaussian peak, in theory, the sensitivity of the method can be improved and since chromatographic separation is not required, shorter analytical time can be attained. The downside, however, is if there is any sulfur containing compounds in the sample retainable by the chromatographic column, it will also be measured as Tertiary dodecyl mercaptan. Method optimization involved selecting the appropriate operating temperature for the analytical column to obtain a symmetric peak for reliable quantitative work. Peak symmetry quality was compared between maintaining the column temperature isothermally versus a slight temperature program.

Comparison of performance between the two approaches
In terms of precision, as stated earlier for the speciated method, the distribution of individual isomers of Tertiary dodecyl mercaptan between 3.5 and 6.0 min was integrated, whereas for the total method, the discreet peak representing Tertiary dodecyl mercaptan was integrated. Standards containing 1000 ppm (v/v) of Tertiary dodecyl mercaptan in iso-octane were used for the evaluation. A relative standard deviation of 2.5% (n = 20) was obtained for the speciated method while a relative standard deviation of 3.9% (n = 10) was obtained for the total sulfur method. The results obtained were tabulated in Table I. In terms of linearity, over the range from 1 ppm to 1000 ppm (v/v) Tertiary dodecyl mercaptan, correlation coefficients R2 of 0.9994 and of 0.9995 were obtained for the speciated and the total sulfur method, respectively. The detection limit for Tertiary dodecyl mercaptan by the total sulfur method was found to be 0.5 ppm (v/v) Tertiary dodecyl mercaptan whereas 1.0 ppm (v/v) for the speciated method as shown in Figures 11 and 12. Table II shows a comparison of five iso-octane extract samples containing Tertiary dodecyl mercaptan. It was found the results obtained were comparable amongst the two methods; despite there is a trend that the Tertiary dodecyl mercaptan results obtained by the total sulfur method is consistently elevated as shown in Figure 13. Some plausible explanations for this bias include the samples might have a different distribution of isomers than Tertiary dodecyl mercaptan used for calibration, or more of the Tertiary dodecyl mercaptan is detected in the samples as isomers are thermally band compressed into a much shorter peak width than classical method.

Nevertheless, the results obtained show that the concept of tracking for the presence of Tertiary dodecyl mercaptan by measuring its sulfur content and associated retention time range in the speciated method or by measuring its sulfur content alone can be employed for the material identification, trend monitoring, or the measurement of residual Tertiary dodecyl mercaptan in various matrices. If a high degree of accuracy is required, the results obtained by using said techniques must be compared to other assaying techniques.

Conclusions
A gas chromatographic technique has been successfully developed for the measurement of Tertiary dodecyl mercaptan based on its sulfur content for raw material identification, trend analysis, or for the measurement of un-reacted material in the final products. The method employs LTM-GC offering the flexibility either for speciation of individual sulfur compounds or delivering peak compression to combine individual sulfur compounds into one
discreet peak without changing of hardware, and a DP-SCD to attain a high degree of sensitivity and selectivity. Using the technique described, a detection limit in the range of 0.5 ppm (v/v) Tertiary dodecyl mercaptan with less than 1 min analysis can be achieved. Response is linear over four orders of magnitude with a high degree of repeatability of less than 5%.

Physicochemical Information
Boiling point   233 °C (1013 hPa)
Density   0.856 g/cm3 (20 °C)
Flash point   98 °C
Ignition temperature   350 °C
Melting Point   -45 °C
Vapor pressure   1.33 hPa (25.5 °C)
Solubility   <0.1 g/l

Evaluation Summary
Tertiary Dodecyl Mercaptan (tert-dodecyl mercaptan, TDM) is a transitional ‘existing’ substance which was discussed by the former EU PBT Working Group on a number of o c c a si on s . As a result of these discussions the substance was included in Regulation (EC) No. 465/2008 of 28th May 2008, which required industry to conduct an enhanced biodegradation test and fish bioconcentration study and submit the results by November 2009. The data were provided in January 2013. Based on the available information, TDM does not meets the Annex XIII criteria for either a ‘persistent, bioaccumulative and toxic’ (PBT) or a ‘very persistent and very bioaccumulative’ (vPvB) substance in the environment.

A recent paper by Comber and Thomas (2013) provided by the registrant suggests that
the water solubility of Tertiary dodecyl mercaptan could be lower than given in the registration dossier. The Comber and Thomas (2013) paper refers to a water solubility for Tertiary dodecyl mercaptan of 0.00393 mg/l obtained in a slow-stir water solubility study.
Details of the new water solubility test (Baltussen, 2013) have recently been provided in a robust study summary. The study was a GLP compliant OECD Guideline 105 study using the slow-stirring method. The substance tested had an analytical purity of 99.1%. The test was carried out by preparing triplicate samples in double distilled water at 19.9±0.4°C and stirring at 40 rpm. At various time points samples were
taken, centrifuged and prepared for analysis, taking care to avoid volatilisation of the test substance (no further details of how this was achieved are given). The concentration of Tertiary dodecyl mercaptan was determined by a validated analytical method involving derivatisation followed by analysis using HPLC/MS/MS (this was presumably a similar method to that discussed in relation to the biodegradation and bioaccumulation data). The pH of the water was in the range 6.5 to 7.1 throughout the test. Samples were analysed at 24, 48, 72, 96, 120 and 144 hours. For the first three samples the concentration was found to increase slightly with time (0.00139 mg/l at 24 hours, 0.00174 mg/l at 48 hours and 0.00217 mg/l at 72 hours). For the latter three sampling times the concentration was found to be more stable, although the maximum difference in the concentration at the three sampling points was >15%. The concentrations measured were 0.00467 mg/l at 96 hours, 0.00415 mg/l at 120 hours and 0.00296 mg/l at 144 hours. The test report concluded that the variability in the results at these sampling points probably reflected the difficulties in accurately determining very low concentrations of Tertiary dodecyl mercaptan rather than a continuing increase in the amount of Tertiary dodecyl mercaptan dissolved (in fact the concentrations declined slightly with time during this phase). The water solubility was therefore determined to be 0.00393 mg/l based on the mean concentration measured between 96 hours and 144 hours.

The robust study summary gives the study a reliability of 2 (reliable with restrictions) as the maximum difference between the measured concentrations at the last three sampling points was >15%. The eMS agrees with this reliability rating and also considers it likely that the variability seen in the measurements reflects the difficulties in measuring low concentrations of this substance rather than a continuing increase in the amount dissolved at the later sampling points. Therefore the actual water solubility of Tertiary dodecyl mercaptan can be taken to be around 0.00393 mg/l (3.93 µg/l) at 20°C. Comber and Thomas (2013) estimated a log Kow value for Tertiary dodecyl mercaptan of 7.43 using a validated QSAR based on this water solubility. A Robust Study Summary and details of the QSAR used have been made available to the eMS. The linear regression model was proprietary and was developed using confidential data sets (details of these were not given), but it was reported that the substance fell within the applicability domain of the QSAR. It should be noted, however, that the types of chemical used to train the model did not appear to specifically contain thiols (although it is not possible to be certain about this as the specific substances used were not given). The applicability of this method to thiols has since been demonstrated for a set of four thiols (primary and secondary), although the log Kow values of these were lower than for Tertiary dodecyl mercaptan (experimental log Kow values of the validation set were between 1.5 and 3.7) (personal communication to the evaluating Member State, 6th December 2013).

A further measured water solubility value for Tertiary dodecyl mercaptan is reported in EA (2005). The water solubility was determined to be 0.25 mg/l at 20°C and the study used a nonguideline protocol (simple flask method) but was carried out according to GLP. This value was used in the EA (2005) assessment but only limited details are available (the registrants do not have access to the study) for this study and so the reasons for the discrepancy between this value and the value of 0.00393 mg/l given above are currently unknown2. The physico-chemical properties of Tertiary dodecyl mercaptan have also been reviewed by EA (2005) and the data presented there are generally consistent with those from the registration dossier but, apart from the water solubility, the main exception is the vapour pressure, which is given as 4 hPa (400 Pa) at 20oC in EA (2005) based on a non-GLP study conducted according to Method A4 of Directive 92/69/EEC. The test report was not available for review by EA (2005) and the registrants do not have access to the study, so the influence of volatile impurities in the test substance is not known.

The value for the vapour pressure reported in EA (2005) is twenty times higher than the value reported in the registration dossier and the reasons for this discrepancy have not been investigated in detail for this evaluation. However, it is relevant to note that EA (2005) estimated a Henry’s law constant for Tertiary dodecyl mercaptan of around 3.24×105 Pa m3 /mole at 20oC based on the water solubility and vapour pressure (EA (2005) assumed a water solubility of 0.25 mg/l for Tertiary dodecyl mercaptan) and commented that this was higher than the Henry’s law constant estimated using the bond contribution method in EPIWIN of 5,900 Pa m3 /mole at 25°C. When the vapour pressure (20 Pa at 25 oC) and water solubility (0.21-0.28 mg/l at 25oC) given in the registration dossier are used to estimate the Henry’s law constant the value obtained is in the region of 14,490- 19,230 Pa m3 /mole at 25oC which is in closer agreement with the EPIWIN estimate than obtained using a vapour pressure of 400 Pa. When the more recent and lower water solubility value (0.00393 mg/l) is considered the Henry’s law constant can be estimated as around 1.03×106 Pa m3 /mole at 25°C using a vapour pressure of 20 Pa (and assuming the change in water solubility with temperature is minor between 20 and 25°C) or 2.06×10 7 Pa m3 /mole at 20°C using a vapour pressure of 400 Pa.

The various estimates of Henry’s law constant, along with the equivalent dimensionless Henry’s law constants (Kaw) are summarised in Table 3. Clearly there is a wide range of values that can be estimated for Tertiary dodecyl mercaptan. The values all suggest that volatilisation from water to air will be an important process in the environmental distribution of Tertiary dodecyl mercaptan. The significance of the range of estimates in relation to longrange transport potential is considered in Section 3.3. Based on the currently available data the best estimate of the log Kaw is probably 2.62 based on the vapour pressure of 20 Pa at 25°C given in the registration dossier and the recent water solubility determination of 0.00393 mg/l at 20°C.

Oxidation
EA (2005) considered that, although abiotic degradation of thiols to disulfides or sulfonic acids by oxidation is reported in the literature, the significance of this process for Tertiary dodecyl mercaptan in the environment was unknown. The registration dossier gives the results of a preliminary oxidation test carried out using the OECD 111 method (reliability rating 2). This test was considered a supporting study in the registration dossier. The Tertiary dodecyl mercaptan tested was a commercial sample with a purity of 99.3%. The test was carried out using both algal culture medium (prepared in accordance with the OECD 201 test guideline) with a pH of 8 and also buffer solution with a pH of 7. Tertiary dodecyl mercaptan was added to the media at 10 mg/l and incubated for up to 150 days at 20°C either under aerated (aerobic) conditions or nonaerated (anaerobic) conditions. A co-solvent (acetonitrile) at 10% v/v was used to maintain the substance in solution. The primary degradation of Tertiary dodecyl mercaptan was followed by parent compound analysis.

Tertiary dodecyl mercaptan was found to degrade slowly under the aerated conditions, with a half-life of approximately 150 days in both algal medium and pH 7 buffer. Under non-aerated conditions the half-life for Tertiary dodecyl mercaptan was found to be approximately 30 days in algal medium and 100 days in pH 7 buffer.

Analyses were also carried out for di-tert-dodecyl disulphide, the anticipated oxidation product of Tertiary dodecyl mercaptan. This was detected at a concentration of 0.2-0.3 mg/l in the non-aerated algal medium experiment but was at or below the limit of quantification (~0.1 mg/l) in the other experimental systems. It was concluded that the levels of ditert-dodecyl disulphide found did not account fully for the level of degradation of Tertiary dodecyl mercaptan seen implying that degradation mechanisms other that oxidation may also be occurring. It was also concluded in the registration dossier that the 30 day half-life measured in the non-aerated algal medium was probably falsely short owing to poor agreement between replicates for the later samples and that overall this test shows that Tertiary dodecyl mercaptan can be degraded slowly in solution but the route/mechanism of degradation is uncertain.

When considering this test, it should be noted that Tertiary dodecyl mercaptan is relatively volatile (vapour
pressure 20 Pa at 25° C). The full test report of the study indicates that precautions
were taken to avoid potential loss from volatilization (use of sealed vials and sampling
via septa). Therefor it is unlikely that volatile loss would have contributed
significantly to the removal of Tertiary dodecyl mercaptan seen. The other point worth noting is that,
although the test was carried out using 10% v/v of acetonitrile as a cosolvent, the
concentration of Tertiary dodecyl mercaptan used (10 mg/l) is well above the recently determined water
solubility of 0.0039 mg/l. The solubility of Tertiary dodecyl mercaptan in an acetonitrile:water mixture is
unknown but it is possible that not all of the Tertiary dodecyl mercaptan would have been in solution in this test.

In conclusion, the results of this study suggest that oxidation of Tertiary dodecyl mercaptan in the environment is likely to be only a minor loss process. Screening tests A modified OECD 310 Test Guideline ready biodegradability test has been carried out with Tertiary dodecyl mercaptan (Davis et al., 2009). The test material used was a commercial sample with a purity of 99.9% and the test was carried out in accordance with GLP.The substance was added to the test system coated on silica gel (as an inert support) in order to maximise its availability to the microbial inoculum in accordance with the ISO 10634 (1995) guidance. Two loading rates were used in the study. A nominal loading rate of 20.5 µmoles Tertiary dodecyl mercaptan/g silica gel (4.15 mg Tertiary dodecyl mercaptan/g) was firstly prepared by adding the test substance directly to the silica gel in a sealed bottle under argon atmosphere and mixing for three days. A nominal loading of 2.05 µmoles Tertiary dodecyl mercaptan/g silica gel was then prepared by mixing 1.1 g of the treated silica gel with 10.3 g of unspiked silica gel followed by mixing for 1 day. The loading rates, and uniformity of the spiked samples were confirmed by analysis of triplicate samples immediately after preparation of the silica gel and after preparation of the test microcosms (the mean loading rates determined were 16.9 µmol/g and 1.70 µmol/g at the two loading rates, respectively).

The inoculum used in the study was derived from activated sludge mixed liquor collected from a municipal waste water treatment plant treating predominantly domestic waste water (>90% from domestic sources). The mixed liquor suspended solids (MLSS) concentration of the activated sludge was 1,230 mg/l and appropriate volumes were added to mineral salts medium to give a nominal MLSS concentration in the test microcosm of either 30 mg/l or 4 mg/l4. The tests were carried out using a series of sealed 160 ml glass serum bottles containing 75 ml of mineral salts media inoculated with MLSS at either 4 or 30 mg/l and containing Tertiary dodecyl mercaptan (adsorbed onto silica gel) at a nominal concentration of either 2 µM (~0.4 mg/l) or 20 µM (~4 mg/l). The 2 µM concentration was around twice the estimated water solubility for Tertiary dodecyl mercaptan (given as 1.4 µM, which is equivalent to a water solubility of 0.28 mg/l (the estimated water solubility given in the registration dossier). As discussed in Section 1.5 a much lower water solubility of 0.0039 mg/l has recently become available and so the 2 µM treatment may have been as much as 100 times higher, and the 20 µM treatment as much as 1,000 times higher than the actual water solubility of Tertiary dodecyl mercaptan. The significance of the new water solubility on the bioavailability of Tertiary dodecyl mercaptan in this study is unclear but it is possible that the bioavailability may still have been limited even though the substance was adsorbed onto silica gel. Viability controls (containing 25 mg/l of aniline and MLSS), toxicity controls (containing MLSS and both aniline and Tertiary dodecyl mercaptan) and inoculum blanks (containing MLSS only) were also prepared. In addition abiotic controls (containing heat sterilized MLSS and Tertiary dodecyl mercaptan) were also prepared in order to assess abiotic loss of Tertiary dodecyl mercaptan. The tests were carried out at 20°C.

The degradation was followed by monitoring the disappearance of Tertiary dodecyl mercaptan at various
time periods (primary degradation). For this, replicate bottles (two or three per time
point) were extracted with acetonitrile for 3 hours on a rotary shaker and the
concentration of Tertiary dodecyl mercaptan determined. In addition, the formation of carbon dioxide
(mineralization) was also determined at certain time points. The degradation of aniline
was determined based on dissolved organic carbon measurements. The concentrations
of Tertiary dodecyl mercaptan measured in the experiments using an initial Tertiary dodecyl mercaptan concentration of 20 µM
are summarized in Table 5. The carbon dioxide measurements taken during the study
indicated that little or no mineralization of Tertiary dodecyl mercaptan was occurring.

About Tertiary dodecyl mercaptan
Helpful information
Tertiary dodecyl mercaptan is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, at ≥ 10 000 to < 100 000 per annum.

Tertiary dodecyl mercaptan is used in formulation or re-packing, at industrial sites and in manufacturing.

Consumer Uses
ECHA has no public registered data indicating whether or in which chemical products the substance might be used. ECHA has no public registered data on the routes by which Tertiary dodecyl mercaptan is most likely to be released to the environment.

Article service life
ECHA has no public registered data on the routes by which Tertiary dodecyl mercaptan is most likely to be released to the environment. ECHA has no public registered data indicating whether or into which articles the substance might have been processed.

Widespread uses by professional workers
ECHA has no public registered data indicating whether or in which chemical products the substance might be used. ECHA has no public registered data on the types of manufacture using Tertiary dodecyl mercaptan. ECHA has no public registered data on the routes by which Tertiary dodecyl mercaptan is most likely to be released to the environment.

Formulation or re-packing
Tertiary dodecyl mercaptan is used in the following products: polymers and pH regulators and water treatment products.
Tertiary dodecyl mercaptan has an industrial use resulting in manufacture of another substance (use of intermediates).
Release to the environment of Tertiary dodecyl mercaptan can occur from industrial use: formulation of mixtures.

Uses at industrial sites
Tertiary dodecyl mercaptan is used in the following products: polymers and pH regulators and water treatment products.
Tertiary dodecyl mercaptan has an industrial use resulting in manufacture of another substance (use of intermediates).
Tertiary dodecyl mercaptan is used in the following areas: mining.
Tertiary dodecyl mercaptan is used for the manufacture of: chemicals and rubber products.

Release to the environment of Tertiary dodecyl mercaptan can occur from industrial use: as an intermediate step in further manufacturing of another substance (use of intermediates), as processing aid, in processing aids at industrial sites and as processing aid.

Manufacture
Release to the environment of Tertiary dodecyl mercaptan can occur from industrial use: manufacturing of the substance.

Tertiary dodecyl mercaptan is used in lubricant intermediates to produce additives as well as final components to improve lubricant performance in base oils and metal working fluids

Tertiary dodecyl mercaptan is a mixture of tertiary mercaptans, predominantly tertiary dodecyl mercaptan (thus the source for its acronym TDM). This product contains highly branched C12H25 alkyl mercaptan isomers, produced by the addition of hydrogen sulfide to propylene tetramer. It is used as a chemical intermediate to introduce bulky C12H25 alkyl-thio substituents into chemical substances. Its major use is as a chain transfer agent to control molecular weight of polymeric systems undergoing free-radical polymerization.

Physical state : Liquid
Color : Colorless
Odor : Repulsive
Flash point : 98 - 110 °C
Oxidizing properties : no
Autoignition temperature : 198 - 230 °C
Thermal decomposition : 149 °C
Molecular formula : C12H26S
Molecular weight : 202,44 g/mol
pH : Not applicable
Melting point/range -16 °C
Boiling point/boiling range : 233 °C
Vapor pressure : 4,00 Paat 24 °C
Relative density : 0,86 at 16 °C
Water solubility : 0,00393 mg/l
Method: OECD Test Guideline 105
Partition coefficient: noctanol/water: Pow: 7,43 at 20 °C
Viscosity, dynamic : 2,6 cP at 20 °C
Relative vapor density : 3 (Air = 1.0)
Evaporation rate : < 1
Primary Chemistry: Sulfole® 120

Features & Benefits
Sulfolane 120 (+b) Tertiary dodecyl mercaptan is a main component to produce metallic decoration (inks) for food packaging (porcelain, ceramics glass). Tertiary dodecyl mercaptan is also a lubricant additive used to improve lubricant performance in base oils and metal working fluids. Last but not least, it is a chain transfer agent in process where control of molecular weigh is critical from Polymer Modifiers in paint and coatings for emulsion polymerization, adhesives (pressure sensitive adh. for labeling) and surfactants & emulsifiers.

Markets
Automotive and transportation
Polymer and rubber
Chemical and plastics industry
Polymer engineering
Packaging and Paper
Paper
Paper and board
Rigid packaging
Specialty paper
Paint, coatings and adhesives
Acrylic resins

Applications
Chain transfer agent

TDM (Tertiary Dodecyl Mercaptan) is commonly used in the manufacturing process of polymers based on butadiene and styrene (SB latex, SB rubber, ABS...)

INDUSTRIAL USE of Tertiary Dodecyl Mercaptan
Intermediaries
Lubricants and Oil Additives
Process regulators

Automotive and Transportation
Oil additive: to produce final components as well as final components to improve lubricant performance in fatty acids and metalworking fluids
We supply a variety of chemicals used in lubricant intermediates.

Polymers and rubber applications
Normal (n-) dodecylmercaptan is used as reagents in the synthesis of antioxidants that minimize the unwanted effects of processes such as thickness balancing.

dodecyl mercaptan, 1-dodecanethiol, lauryl mercaptan, NDDM, CAS # 112-55-0) are used.

Consumer uses
Plastic and rubber products not covered elsewhere

Help on calculated properties New window
Property name Property value Reference
Molecular weight 202.4 g / mol calculated by PubChem 2.1 (PubChem release 2019.06.18)
XLogP3-AA 4.8 calculated by XLogP3 3.0 (PubChem release 2019.06.18)
Number of hydrogen bond donors 1 calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Number of hydrogen bond acceptors 1 calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Number of rotary links 3 calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Exact mass 202.175522 g / mol calculated by PubChem 2.1 (PubChem release 2019.06.18)
Monoisotopic mass 202.175522 g / mol calculated by PubChem 2.1 (PubChem release 2019.06.18)
Topological polar surface 1 Å² calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Number of heavy atoms 13 calculated by PubChem
Formal load 0 calculated by PubChem
Complexity 176 calculated by Cactvs 3.4.6.11 (PubChem version 2019.06.18)
Number of isotopic atoms 0 calculated by PubChem
Defined number of atomic stereocenters 0 calculated by PubChem
Undefined atomic stereocenter number 0 calculated by PubChem
Defined number of bond stereocenters 0 calculated by PubChem
Number of undefined binding stereocentre 0 calculated by PubChem
Number of covalently bound units 1 calculated by PubChem
The compound is canonized Yes

Building materials, flooring Materials for flooring (carpet, wood, vinyl flooring) or related to flooring such as wax or floor varnish

General manufacturing information
Processing sectors of the industry
All other basic organic chemical manufacturing

Manufacture of paints and coatings

Plastic and resin manufacturing

Synthetic rubber manufacturing

Tertiary dodecyl mercaptan (tertiary dodecyl mercaptan) is commonly used as a chain
transfer agent in the manufacturing process of styrene / butadiene latex for use in the carpet and paper industries. A technical gas chromatography has been successfully developed for the measurement of tertiary dodecyl mercaptan based on its sulfur content for material identification, trend analysis, or for monitoring unreacted residual material in finished products. The process uses low thermal mass gas chromatography (LTM-GC) and dual plasma sulfur chemiluminescence detector (DP-SCD) to achieve a high degree of sensitivity and selectivity. Using the described technique, a detection limit of between 0.5 ppm (v / v) tertiary dodecyl mercaptan and less than 1 minimum analysis time can be achieved. The response is linear over four orders of magnitude with a high degree of repeatability less than 5% RSD.

introduction
In the process of making a latex such as styrene-butadiene, a chain transfer agent is needed. The chain transfer agent assists in polymerization to produce products of the desired molecular distribution. Previously, chlorinated compounds such as carbon tetrachloride and chloroform were
used for this application, but because of their toxicity and their negative environmental effects, it is no longer a practice to employ said compounds for the manufacture of latices used for the carpet and paper industries. Instead, the use of tertiary dodecyl mercaptan (tertiary dodecyl mercaptan) is preferred for the applications described. As a result of the worldwide demand for latex and the scale of the associated industries, tertiary dodecyl mercaptan has become an industrial chemistry of importance.
From a manufacturing point of view, tertiary dodecyl mercaptan is a mixture of isomeric thiols produced from oligomers of propylene tetramer or sometimes, isobutylene trimer. The propylene tetramer is produced by oligomerization of propylene in the presence of a FriedelCrafts type catalyst such as sulfuric acid. Tertiary dodecyl mercaptan is produced by passing hydrogen sulfide and either propylene tetramer or
isobutylene trimer on a catalyst such as boron trifluoride.
Due to the fact that there are many permutations of the
tetrameric structure, and therefore the location of the –C = C– bond,
the thiol group can be localized in many different positions, resulting in a mixture of isomeric products with a medium boiling point range around 230 ° C.

Recently there have also been growing concerns concerning the accumulation of tertiary dodecyl mercaptan in the environment.
The open literature contains little or no information on the analysis of tertiary dodecyl mercaptan. Part of this is because the matrix can be quite complex. An example would be the water soluble polymeric emulsion, comprising hundreds of components that can cause chromatographic interference. In addition, alkylmercaptans such as tertiary dodecyl mercaptans are difficult to analyze for reasons such as alkyl chains are size C8 to C15 and cover a wide boiling range points, the polarity of individual components in Tertiary Dodecyl Mercaptan varies with the degree of thiolation, the location of the R-SH group. In in addition to the differences in polarity and boiling point of Components Tertiary dodecyl mercaptan the product may also contain a relatively nonpolar and non-thiolated tetramer fraction. For measurement tertiary dodecyl mercaptan, an internal method involves the use of headspace gas chromatography in combination with photometric flame detection (FPD) has been developed. The method, however, has its constraints, including competing vapor-liquid equilibrium solutes in the sample and the lack of linear dynamic range of the FPD.

As a result, a new chromatographic method is needed for the identification of tertiary dodecyl mercaptan materials, for trend analysis and for the monitoring of residual materials in finished products. The new chromatographic method was developed with three catalysts: (i) Liquid-liquid extraction to remove tertiary Dodecyl mercaptan isomers from their respective matrices; (ii) Low temperature mass gas chromatography to provide the flexibility of speciation of individual sulfur compounds or maximum compression to combine individual sulfur compounds into a single discrete peak with ability to program temperature and improve sample overall for sample the flow; (iii) Sulfur Dual Plasma Chemiluminescence Detector (DP-SCD) to provide the highest degree of selectivity for tertiary Dodecyl Mercaptan isomers, equi-molar response and respectable linear dynamic range.
This report summarizes the development of the method and the analytical results obtained.