This test method covers the determination of typical Thiophenic sulfur impurities found in Styrene monomer extracted from Pygas. This test method also determines non-thiophenic sulfur compounds as a group, calculated using 1-Hexanethiols response. This test method is applicable to finished Styrene monomer from Pygas extraction, Styrene monomer derived from Ethylbenzene, and other upstream styrene concentrate samples from the same processes. The applicable concentration range will vary to some extent depending on the instrumentation used and calibration range. Typical lower limit of detection of this method is 0.4 ppm S or lower. This test method is not intended to identify all thiophenic and non-thiophenic compounds.
Sulfur; Styrene; Thiophenic sulfur; non-Thiophenic sulfur
It has been studied that mercaptans and disulfides in styrene monomer negatively affect the downstream polymerization of Styrene. Adversely, Thiophenic sulfur is not harmful to the styrene polymerization process. Therefore there needs to be a standard method which determines the two types of sulfur in Styrene monomer (thiophenic and non-thiophenic). Furthermore, Styrene monomer specification (ASTM D2827) may change in the future to reflect non-thiophenic sulfur limitation. Thus this method can be used for the determination of the non-thiophenic sulfur in Styrene as will be specified in the new ASTM D2827.
The title and scope are in draft form and are under development within this