Active Standard ASTM D1926 | Developed by Subcommittee: D01.36
Book of Standards Volume: 06.03
Historical (view previous versions of standard)
Significance and Use
These test methods measure the amount of carboxyl groups present in wood or cotton linter pulp. Carboxyl groups are indicative of the surface charge of the pulp which is a very important quantity for use in the papermaking industry.
1.1 These test methods cover the determination of the carboxyl content, or ion-exchange capacity, of cellulose from any source. Two test methods are described, the sodium chloride-sodium bicarbonate method (1) and the methylene blue method (2). The test methods must be used within their limitations, and it must be recognized that there is no way of determining the accuracy of any method for the determination of carboxyl. The precision of the sodium chloride-sodium bicarbonate method is low in the lower range of carboxyl values. The methylene blue method can be used over the whole range of carboxyl values; it is especially useful in the low range. It is not applicable to the determination of carboxyl in soluble carbohydrate material. Although these test methods may be used to determine the ion-exchange capacity of unbleached pulps, the residual lignin will cause an undetermined error, especially the sulfonic acid groups in unbleached sulfite pulps (3).
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D1193 Specification for Reagent Water
ICS Number Code 85.040 (Pulps)
UNSPSC Code 12352200(Biochemicals)