This part of GB/T 9345 specifies three methods for the determination of the ash of poly(vinyl chloride). The general procedures given in GB/T 9345.1 are followed. For ash, method A is used. For sulfated ash, methods B and C are used. All three methods are applicable to resins, compounds and finished products. Methods B and C are applicable when lead-containing compounds are present.
2 Normative References
The following normative documents contain provisions which, through reference in this part, constitute provisions of this part of GB/T 9345. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this part. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 9345.1—2008 Plastics—Determination of Ash Part 1: General Methods (ISO 3451-1: 1997, IDT)
3 Principle
3.1 Method A (direct calcination)
The organic matter in a test portion is burnt off and the residue is heated at 950℃ until constant mass is reached.
3.2 Method B (calcination, with sulfuric acid treatment after combustion)
The organic matter in a test portion is burnt off, the residue is converted into sulfates using concentrated sulfuric acid and, finally, the residue is heated at 950℃ until constant mass is reached.