BS ISO 1762:2019 pdf free

BS ISO 1762:2019 pdf free.Paper, board, pulps and cellulose nanomaterials – Determination of residue (ash content) on ignition at 525 °C
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.
Determine the moisture or dry matter content on the relevant test specimen (air-dry) using the procedure described in ISO 287 or ISO 638, as relevant. Do not use the moisture or dry matter content test specimen for incineration. Weigh the crucible containing the moisture or dry matter content test specimen at the same time as the crucible containing the test specimen (air-dry) used for incineration (see 7.3).BS ISO 1762 pdf free download.