Handling properties

Neat ADN contains crystals shaped as needles or flakes. No method for re-crystallizing ADN to give more uniformly-shaped crystals has been reported. The ill-shaped crystals limit the amount of ADN in cast-cured compositions due to high viscosity. The only solution to this problem is to reshape the ADN crystals to be more regular. Since the melting point is not directly associated with decomposition, it is possible to use a method whereby ADN is melted. 

A laboratory scale prilling process is simply melting ADN in an immiscible liquid. Stirring above the melting point causes shearing forces to produce droplets, which are quenched to hard spheres upon cooling of the mixture. This process is also an opportunity to dissolve stabilizers in the ADN while molten. 

A problem with this process is the decomposition of ADN as the temperature is raised above the melting point. The problem is that the melting point at 92°C is only 40°C below the temperature of decomposition. At 110°C the decomposition becomes autocatalytic after 15 minutes, at 98°C after a few hours. This is not a problem on the laboratory scale, where the melting period can be reduced to a few minutes. On the industrial scale, where hundreds of kilos of ADN should be melted in a batch, the time is much longer. It is likely that most explosives producers would hesitate and most likely refrain from scaling up this process unless nothing is changed. 

A continuous method for prilling ADN has been invented that might be a solution to the safety problem [27]. The ADN is fed continuously into a heating zone, where it is melted, and then into a nonsolvent cooling fluid. This method would probably also increase the capacity and operational costs for prilling. 

Energetic Materials, Part 1 Decomposition, Crystal and Molecular Properties Theoretical and Computational Chemistry, Vol. 12 2003 Elsevier B.V. All rights reserved. 

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Table 3. Bulk Phase Handling Properties of Adipic Acid...

Although there is no official ASTM test to measure the water handling properties of gasoline, there are a number of widely used industry tests. One uses a Waring Blender to simulate high shear (57), whereas another uses a wrist action shaker to simulate mild shear conditions (58). 

The apex (often referred to as bead filler) compound must be formulated for excellent dynamic stiffness to facilitate stress distribution and provide good car handling properties. The bead insulation compound must possess good adhesion to this most important component for enclosing the pHes of the tire and holding the tine to the rim. The chafer/rim strip compound protects the pHes from rim abrasion and seals the tire to the rim. 

The submerged metal belt (Fig. ll-53b) is a special version of the metal belt to meet the peculiar handling properties of pitch in its solidification process. Although adhesive to a dry metal wall, pitch will not stick to the submerged wetted belt or rubber edge strips. Submergence helps to offset the very poor thermal conduclivity through two-sided heat transfer. 

Veronovski, N., Rudolf, A., Smole, M.S., Kreze, T. and Gersak, J. (2009) Self cleaning and handle properties of Ti02-modified textiles. Fibers and Polymers, 10, 551-556. 

In the pharmaceutical industry, surface area is becoming more important in the characterization of materials during development, formulation, and manufacturing. The surface area of a solid material provides information about the void spaces on the surfaces of individual particles or aggregates of particles [5], This becomes important because factors such as chemical activity, adsorption, dissolution, and bioavailability of the drug may depend on the surface on the solid [3,5]. Handling properties of materials, such as flowability of a powder, can also be related to particle size and surface area [4],... 

Similar exercises must be performed to identify synthetic nanocomponents. Considerations include suitability for the proposed environment, synthesis and handling properties, polydispersity, structural / chemical properties, as well as amenability to assembly into higher order structures. For medical devices, tolerability and safety of the structural materials is also an issue. Current materials technology offers powerful, but limited capacity to engineer an off the shelf approach to nanostructures. 

I I heology is an integral part of life, from decorative paint and movement of volcanic lava to the flow of blood in our veins. This book describes, without the use of complex mathematics, how atoms and molecules interact to control the handling properties of materials ranging from simple ionic crystals through polymers to colloidal dispersions. 

A. Martinez-Arias, M. Femandez-Garcia, C. Belver, J. C. Conesa, and J. Soria, EPR study of oxygen handling properties of ceria, zirconia and Zr—Ce (1 1) mixed oxide samples, Catal. Lett. 65,197-204 (2001). 

Plasticizers are used in the polymer industry to improve flexibility, workability, and general handling properties. Dibutyl sebacate and phthalates, such as dibutyl phthalate, diethyl phthalate, dicyclohexyl phthalate, butylbenzyl phthalate, and diphenyl-2-ethylhexyl phosphate, serve widely as plasticizers in vinylidene chloride copolymers, nitrocellulose-coated regenerated cellulose film, and cellulose acetate (Castle et ah, 1988a). In PVC, di(2-ethylhexyl)... 

The enthalpies of formation of 5-triazolinone (20) [—(142.4 0.7) kJ mol ], 3-nitro-5-tri-azolinone (21) [—(129.4+ 1.1) kJ mol ] and the sodium and potassium salts of (21) have been determined <91JCT1169). Compounds of this type are of interest as potential explosives with good handling properties. 

Bulk powder properties are important in understanding the handling properties of an excipient or a granulated product. Common parameters measured are bulk and tap density. From these values the compressibility can be calculated using the following ... 

The classification system introduced by Carr [29,30] was used to evaluate the flow properties of the sorbitol powders. In Carr s system, a flowable powder is defined as free flowing and will tend to flow steadily and consistently. This is to be contrasted with a floodable powder, which will exhibit an unstable, discontinuous, and gushing type of flow. The parameters in Carr s system include the angle of repose, angle of spatula, compressibility, cohesion, and dispersibility. Based on these parameters, flowability and floodability indices are calculated to determine the handling properties of bulk solids. 

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