Значење и употреба

4.1 This test is a sensitive measure for degradation of cellulose resulting from the action of heat, light, acids, bases, oxidants and reducing agents during processing or purification. If desired, the intrinsic viscosity value can be converted to degree of polymerization (DP) or intrinsic fluidity.

4.2 Cellulose solutions are not Newtonian liquids; That is, their viscosity depends on the shear rate or velocity gradient during the measurement. For low molecular weight (DP) samples and low concentration samples, this effect is smaller than for high DP samples and high concentration samples. For cellulose and concentrations contained within the limits described in this test method, the effect of shear rate is assumed to be negligible for judging purposes. This assumption may not be valid for other conditions and for research purposes, but a way to discuss this effect is beyond the scope of this test method.

ASTM D1795-2013 Standard Test Method for the Characteristic Viscosity of Cellulose

Корак 1: Обим

1.1 This test method includes the determination of the intrinsic viscosity of purified cellulose, such as bleached wood pulp, cotton lint and regenerated cellulose. It is suitable for all cellulose samples with an intrinsic viscosity of 15dl/g or less. Most natural (unpurified) cellulose has intrinsic viscosity values that are too high to be measured by this test method.

Белешка 1 – The use of cuprammonium hydroxide solution for conventional viscosity determination is described in Method T206m-55 of the Pulp and Paper Industry Technical Association on “Cuprammonium Dispersion Viscosity of Pulp” and Joint Army-Navy Specification JAN-C-. 206.

1.2 Values expressed in SI units shall be regarded as standard values. Никакве друге мерне јединице нису укључене у овај стандард.

1.3 Овај стандард није намењен да реши све безбедносне проблеме, ако их има, повезана са његовом употребом. Одговорност корисника овог стандарда је да успоставе одговарајуће безбедносне и здравствене праксе и да утврде применљивост регулаторних ограничења пре употребе.