Stabilizer exudation

Compatibility Many stabilizers exude from the polymer during fabrication, storage or irradiation. One way of preventing this is to incorporate long alkyl chains into the stabilizer molecule which acts as a link. 

Thermal Stability, Piging and Exudation ofMETN Propellants, PubHcation LL 77-29, CPIA, Laurel, Md., 1977. 

Organic compounds released from plant roots have been categorized according to (a) their chemical properties, such as stability (e.g., hydrolysis and oxidation), volatility, molecular weight, solubility in water, etc. (Chap. 2) (b) the modality of their release (exudates, secreted, or lysates) (c) the way of utilization... 

The nature of the nitrocellulose used is of particular importance in explosives if freedom from exudation of free nitroglycerine during storage is to be avoided. Nitroglycerine is only a poor solvent for nitrocellulose and stability of the gel depends on continuous formation and breakdown of gelled structures. The distribution of nitrogen content and viscosity, even in the individual fibres of the nitrocellulose, is therefore of paramount importance. 

It is normally found in the Caribbean, the South Pacific, Southeast Asia, the West Indies, India, and the Middle East. The natural reservoirs are humans, primates, and mosquitoes. Does not produce disease in animals. This is a biosafety level 2 (classical) or 3 (hemorrhagic) agent. Typically a fulminant, nonlethal disease however, it may progress to a hemorrhagic form. Stabile outside a host in dried blood and exudates for up to several days at room temperature. 

Gum, arabic. This thickening agent used for stabilizing emulsions is made from the dried exudate of the stems of the Acacia Senegal. 

The compounding technique for latex differs from that of dry mbber and is fundamentally simpler. A critical factor of colloidal stability makes necessary that each ingredient is of optimum particle size, pH, and concentration when added as an aqueous dispersion to the latex. Rubber latex is a colloidal aqueous emulsion of an elastomer and natural mbber latex is the milky exudation of certain trees and plants that of greatest commercial importance is the... 

The exudate had a much lower stability and brisance than a-TNT but the same sensitivity to friction or impact. In some of the I05mm shells as much as 39-5g of exudate was collected, which amounts to 1.8% of total TNT present (Ref 5)... 

A second consideration concerned with propellant storage and which applies specifically to slurried propellants is its mechanical stability. The suspended particles must remain in stable suspension in the gelled liquid for long times, and the mixture must not exude liquid (syneresis). To... 

Besides the gravimetric density test which is conducted with unwrapped cartridges, and the exudation test which can be conducted either with unwrapped cartridges or with prepd samples, the following stability tests are recommended before proceeding with complete chemical analysis... 

Residual alkalinity in expls and in propellants is undesirable because even traces of alkalies may lower the stability and mp of an expl with a resulting increase in exudation. Alkalies also may form products which are more sensitive than the original expl.Some discussion on this subject is given under Alkalies, Action on Nitric Esters and... 

Ref 50). By the addn of Al to such mixts, expls were obtained having brisance and stability characteristics equal to TNT. However, when cast-loaded into 3" shell and detonated, the expl was of too low brisance for military use. Addn of Ammpicratetothe basic ternary mixt resulted in an expl of satisfactory brisance but upon storage at elevated temps, the expl exuded (See also Addnl Ref H on p a352)... 

---