BS ISO 1762:2019 pdf download – Paper, board, pulps and cellulose nanomaterials – Determination of residue [ash content) on ignition at 525 °C

02-26-2022 comment

BS ISO 1762:2019 pdf download – Paper, board, pulps and cellulose nanomaterials – Determination of residue [ash content) on ignition at 525 °C
6.2 Paper, board and puψp sampling
Guidance on obtaining representative samples found in ISO 186 for paper and board and in ISO 7213 for pulps delivered in bales or rolls shall be followed in cases where the analysis is being conducted to evaluate a lot. In this case or if the tests are made on another type of sample, take test specimens from various parts of the sample making sure they are thoroughly representative of the sample. The test specimen taken for incineration shall consist of a number of small pieces no larger than 1 cm2. In a similar manner, obtain a moisture content or dry matter content specimen from the sample. The specimen for incineration shall have a total mass of not less than 1 g on an oven-dry basis, and sufficient to give a residue on ignition of not less than 10 mg and preferably over 20 mg (see Clause Z). If the material has a very low residue on ignition (for example, in the case of so-called ashless grades), it might be necessary to divide the test specimen into two or several smaller portions which are incinerated consecutively in the same crucible, in order to obtain a total residue of at least 10 mg.
6.3 Cellulose nanomaterial sampling
For cellulose nanomaterials, care should be taken that the procedure is appropriate for the material being sampled. There is no ISO standard procedure for sampling cellulose nanocrystals, either in aqueous suspensions or dried forms, or for sampling dilute (wet) cellulose nanofibrils. When the original cellulose nanomaterial sample is a wet form or an aqueous suspension (dilute or concentrated), it shall be dried using an appropriate method such as heating at 105。C, freeze-drying or spray-drying, to give the sample in a solid form such as flakes, powder or other solid, which shall be mixed to homogeneity. The test specimen shall be obtained from this pre-dried sample. In a similar manner, obtain a moisture content or dry matter content specimen from the sample. Filtration to concentrate dilute samples prior to drying is not recommended as it may result in loss of dissolved material which gives ash upon heating to 525 °C. Chemically modified pulps are often prepared through TEMPO-mediated oxidation, carboxymethylation or phosphorylation prior to the production of cellulose nanofibrils (CNF). Chemically modified pulps, CNF made from chemically modified pulps, as well as cellulose nanocrystals (CNC) extracted from pulps by sulfuric acid hydrolysis or oxidative procedures, may contain various cations associated with the ionic carboxylate or phosphate groups introduced at the surface during production. When these pulps or cellulose nanomaterials are in the acidic form (i.e. contain only protons as the cations), they will have very low ash content. The ash content will be greater in pulps and cellulose nanomaterials containing metal cations, such as sodium or calcium, or organic cations such as alkyl ammonium cations. NOTE TEMPO stands for 2,2,6,6-tetramethylpiperidine-1-oxyl.

Download Link Download
PS: If you don't mind, please turn off your ad blocker.

LEAVE A REPLY

Anonymous netizen Fill in information