Hygroscopicity classification

Hygroscopicity Expose samples to various RH values and measure weight gain after 1 week Perform at 93 or 97%RH, 53% RH, and other values of interest. Assign hygroscopicity classification to each salt... 

TABLE 16 Classification of Hygroscopicity and Example Pharmaceutical Excipients... 

DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Poison by ingestion. A corrosive irritant to skin, eyes, and mucous membranes. Explosive reaction with sodium. Violently hygroscopic. Violent reaction with rubidium (at 60°C), potassium. When heated to decomposition it emits toxic fumes of VO and CL. See also VANADIUM COMPOUNDS and HYDROCHLORIC ACID. 

The classification of saline nitride implies the presence of the N ion, and as we discussed in Section 14.1, this is unlikely. However, it is usual to consider Li3N, Na3N (see Section 10.4), Be3N2, Mg3N2, Ca3N2, Ba3N2 and AIN in terms of ionic formulations. Hydrolysis of saline nitrides liberates NH3. Sodium nitride is very hygroscopic, and samples are often contaminated with NaOH (reaction 14.50). 

PET, nylon, ABS, and PC come under the classification of hygroscopic resins. These types of polymer resin collect moisture inside the peUet itself. Removal of this moisture requires dry air as weU as heat. These resins therefore demand proper design and carefnl machine selection for each application. Desiccant dryers are the dominant technology for these resins. 

Classification Aliphatic polyester polymer Properties M.w. 6,000-600,000 hygroscopic Environmental Biodeg. 

Polymer Chemical category and classification Glass transition temperature (7 g) Molecular weight (MW) Solubility Hygroscopicity Solubility parameter Degradation temperature Technologies... 

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