Plastic solids

Wax usually refers to a substance that is a plastic solid at ambient temperature and that, on being subjected to moderately elevated temperatures, becomes a low viscosity hquid. Because it is plastic, wax usually deforms under pressure without the appHcation of heat. The chemical composition of waxes is complex all of the products have relatively wide molecular weight profiles, with the functionaUty ranging from products that contain mainly normal alkanes to those that are mixtures of hydrocarbons and reactive functional species. 

Spirals have been manufactured from concrete, plastics, solid rubber, iron, and special iron alloys. 

Figure 7.2. Response of elastic-plastic solid to planar impact at X = 0 u = longitudinal particle velocity. Measurements are made as a function of time at fixed Lagrangian position X.

The third test shown in Fig. 17.2 is the compression test. For metals (or any plastic solid) the strength measured in compression is the same as that measured in tension. But for brittle solids this is not so for these, the compressive strength is roughly 15 times larger, with... 

Fig. 2.8. Idealized elastic/perfectly plastic solid behavior results in a stress tensor in which there is a constant offset between the hydrostatic (isotropic) loading and shock compression. Such behavior is only an approximation which may not be appropriate in many cases.

Fig. 8-5 Rheology and flow properties of plastics (solid curve) and water (dotted curve).

Degrade plastics (solid waste) by one of four processes biodegradation, photodegradation, chemical degradation, and hydrodegradation. 

This dosage form will be most familiar to the pharmacist since it is used for companion animals (dogs and cats) and is sold in most drugstores, supermarkets, and animal health product centers. There are two types of flea and tick collars, also known as slow-release pesticide generators vaporous and powder-producing collars. Both contain the insecticide and a plasticized solid thermoplastic resin. 

Quillen, C.S., Mixing liquids, pastes, plastics, solids, continuous mixing, Chemical Engineering, 61, pp. 178-224 (June 1954). 

It is important when using the term yield stress to distinguish between an extrapolated value, sometimes called the dynamic yield stress and a true or static yield stress . The latter can only be observed for plastic solids whilst the former is readily obtained with pseudoplastic liquids. In practical terms this can be critical in evaluating the performance of a material. 

Petroleum becomes more or less a plastic solid when cooled to sufficiently low temperatures. This is due to the congealing of the various hydrocarbons that constitute the oil. The cloud point of petroleum (or a product) is the temperature at which paraffin wax or other solidifiable compounds present in the oil appear as a haze when the oil is chilled under definitely prescribed conditions (ASTM D2500, D3117). As cooling is continued, petroleum becomes more solid, and the pour point is the lowest temperature at which the oil pours or flows under definitely prescribed conditions when it is chilled without disturbance at a standard rate (ASTM D97). 

Chemical/Physical. Wet oxidation of acrolein at 320 °C yielded formic and acetic acids (Randall and Knopp, 1980). May polymerize in the presence of light and explosively in the presence of concentrated acids (Worthing and Hance, 1991) forming disacryl, a white plastic solid (Humburg et al., 1989 Windholz et al, 1983). 

Docusate Sodium. Aerosol OT, Colace, and Doxinate are trade names of docusate sodium [577-11-7] (dioctyl sodium sulfo succinate, sodium salt of l,4-bis(2-ethylhexyl)ester butanedioic). This white, wax-like, plastic solid, with a characteristic odor suggestive of octyl alcohol, is usually available in the form of pellets. One gram of the sodium salt slowly dissolves in about 70 mL water. Docusate sodium is freely soluble in alcohol and glycerol, very... 

Zisman discovered that there is a critical surface tension characteristic of low-energy solids, such as plastics and waxes. Liquids ihat have a lower surface tension than the solid will spread on that solid, while liquids with a higher surface tension will not spread. Examples of critical surface tension values for plastic solids in dynes per cm are "Teflon/ 18 polyethylene, 31 polyethylene terephthalate, 43 and nylon, 42-46. As one indication of the way this information can be used in practical applications, one can consider the bonding of nylon to polyethylene. If nylon were applied as a melt to polyethylene, it would not wet the lower-energy polyethylene surface and adhesion would be poor. However, molten polyethylene would spread readily over solid nylon to provide a strong bond. 

Cubic Plastic Solid Crystals Crystal at Lower... 

Utilize plastic, solid-floored cages with sufficient space (e.g., <5 animals per cage). The mouse holding room should be kept at approximately 21°C, on a 12/12 h light cycle. As mice are nocturnal, the light cycle may be inverted if spontaneous activity measures are needed (16). 

Utilize plastic, solid-floored cages with sufficient space for mice to exercise and fully rear up. Note that enrichment items, such as cardboard tunnels, can improve general welfare but may also affect experimental outcomes or increase territorial aggression. 

Cocoa Butter Substitute occurs as a white, waxy solid that is predominantly a mixture of triglycerides derived primarily from palm, safflower, sunflower, or coconut oils. The resulting products may be used directly or with cocoa butter in all proportions for the preparation of coatings. In contrast to many edible oils and hard butters, Cocoa Butter Substitute has an abrupt melting range, changing from a rather firm, plastic solid below 32° to a liquid at about 33.8° to 35.5°. 

Coconut Oil (Unhydrogenated) occurs as a viscous, white to light yellow-tan liquid. It is obtained from the kernel of the fruit of the coconut palm Cocos nucifera (Fam. Palmae). The crude oil obtained by mechanically pressing dried coconut meat (copra) is refined, bleached, and deodorized to substantially remove free fatty acids, phospholipids, color, odor and flavor components, and other non-oil materials. Compared with many natural fats, Coconut Oil (Unhydrogenated) has an abrupt melting range, changing from a rather firm, plastic solid at about 21° or below to a liquid at about 21°. 

Dioctyl Sodium Sulfosuccinate occurs as a white, waxlike, plastic solid. One gram of sample dissolves slowly in about... 

The spiropyrans are not photochromic in the solid state but do exhibit photochromic behavior when dissolved in any of the following solvents, gels, films, plasticized resins, and plastic solids. 

PAT should be used for such studies only when other techniques fail to reveal clearly a given phase transition. Thus, in Figure 4.13, it is interesting to note that the liquid/plastic transition is not detected through the PALS and DB parameters, although it is easily seen by direct observation. On the opposite, the plastic/solid transition is well marked, although it is not easily seen by using conventional techniques. 

Forsyth, M., Meakin, P., MacFarlane, D.R., Hill, A.J. (1993) Positron annihilation lifetime spectroscopy as a probe of free volume in plasticized solid polymer electrolytes . Electrochimica Acta, 40(13), 2349. 

An interesting characteristic of mthenocene is that it is a photoinitiator for the anionic polymerization of ethyl 2-cyanoacrylate. Solutions with millimolar concentrations of the complex in neat cyanoacrylate polymerize to a hard, plastic solid within seconds upon exposure to light. The low concentration of mthenocene required for the polymerization makes it desirable in applications such as coating and adhesives that require solvent-free solutions of monomer. ... 

---