Kraft lignin — Determination of thermal stability by thermogravimetry

1.1

This Standard describes the thermal analysis of kraft lignin using thermogravimetric methods.

Thermogravimetry can be used to determine the initial decomposition temperature(s), rate(s) of decomposition, and the temperature at maximum decomposition of various materials, including lignins at atmospheric pressure. All these temperatures are solely based on the mass loss and are not necessarily the real decomposition temperatures, because not all decompositions can generate evaporation at atmospheric pressure. Thus, these values are only for comparison purposes.

This procedure is applicable to solid (e.g., powdered form) lignins isolated from the kraft pulping process. It does not apply to raw black liquor.

Thermogravimetric measurement may be performed under different types of atmosphere, e.g., an inert atmosphere or an oxidative atmosphere.

1.2

In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.