LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
2. PHYSICAL-CHEMICAL DATA
2.1 MELTING POINT
(a)
Value: 198.5 o C
Decomposition: Onset at 444 o C (47% weight loss at 500 o C)
Method: Thermal analysis was performed on the Netzsch DSC 204C and TG209C
with N2 atmosphere.
GLP: Yes [ ] No [X] ? [ ]
Test Substance: C10-14 Monoalkylbenzene sulfonic acid, sodium salt (CAS #85117-50-6);
mean molecular weight = 348, average alkyl chain length = C12.0. The test
material is a commercial product, contains 85% active matter and is a coarse,
cream-colored powder at 25 o C.
Remarks: This measured melting point value is significantly lower than the EPI Suite
estimated values for other LAS materials. Note that the activity represents
the total percent active materials (LAS, iso-LAS and DATS) in the test
substance. The nonactive material in a powdered sample of LAS is likely
sodium sulfate and other salts which have very high melting points (e.g.,
sodium sulfate = 884°C) and would not interfere with the measurement of
the LAS melting point.
Reference: Huntsman. 2002. Report of melting point analysis for NANSA HS 85/5.
Cover memo from A. Ashworth to K.B. Sellstrom dated April 12, 2002.
Reliability: 2 Valid with restrictions
(b)
Value: 274 o C
Decomposition: Not identified
Method: Estimation: EPI Suite (Mean or Weighted MP)
GLP: Yes [ ] No [X] ? [ ]
Test Substance: C10 LAS (CAS #1322-98-1)
Remarks: Structure modeled is the pure C10 sodium salt homologue, 2-phenyl isomer,
not the commercial material.
Reference: USEPA. 2000. EPI Suite v3.10.
Reliability: 2 Valid with restrictions. Standard EPA estimation software.
(c)
Value: 279 o C
Decomposition: Not identified
Method: Estimation: EPI Suite (Mean or Weighted MP)
GLP: Yes [ ] No [X] ? [ ]
Test Substance: C11 LAS (CAS #27636-75-5)
Remarks: Structure modeled is the pure C11 sodium salt homologue, 2-phenyl isomer,
not the commercial material.
Reference: USEPA. 2000. EPI Suite v3.10.
Reliability: 2 Valid with restrictions. Standard EPA estimation software.
(d)
Value: 284 o C
Decomposition: Not identified
Method: Estimation: EPI Suite (Mean or Weighted MP)
GLP: Yes [ ] No [X] ? [ ]
Test Substance: C12 LAS (CAS #25155-30-0)
Remarks: Structure modeled is the pure C12 sodium salt homologue, 2-phenyl isomer,
not the commercial material.
Reference: USEPA. 2000. EPI Suite v3.10.
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