The Other Properties

In the present section some other properties of epoxy polymers will be considered briefly, namely thermal expansion, anharmonicity, heat capacity and microhardness. 

The authors of paper [76] showed the distinction of micro- and macroexpansion in amorphous polymers and explained it by a certain degree of ordering of chain macromolecules. In other words, the authors [76] found interconnection of thermal expansion and supramolecular structure for a number of amorphous polymers. However, the quantitative structural model for absence of the amorphous state does not allow similar interconnection details to be more precise. Therefore the authors [77] carried out the study of interconnection for amorphous epoxy polymers EP-1 and EP-2 of thermal expansion and structure, for the description of which the cluster model [8, 9] was used. 

This distinction can be explained within the frameworks of the cluster model, which is similar to that used in paper [76], excluding the type of local order domains. Slutsker and Filippov [76] supposed that those domains were the analogue of a crystallite with folded chains, whereas clusters are the amorphous analogue of a crystallite with extended chains [9]. Following the reasons in the paper [76] one can say that 

For an inextensible thread, which simulates a macromolecule part, under the assumption of sinusoidal oscillations, the wavelength can be written as follows [76]  

The obtained oscillation wavelength values can be compared approximately with local order domain longitudinal length, which in model [8,9] is accepted to be equal 

---

The principal characteristics of bitumen are its softening point and its needle penetrability. In France the latter has always been the basis for bitumen classification and class designation. Yet, the former is more representative of a bitumen s capacity to deform when the service temperature increases. The other properties have more or less importance depending on the application. 

The fact that two operators commute is of great importance. It means that once a measurement of one of the properties is carried out, subsequent measurement of that property or of any of the other properties corresponding to mutually commuting operators can be made without altering the system s value of the properties measured earlier. Only subsequent measurement of another property whose operator does not commute with F,... 

Table 1.3 shows a rough breakdown of material prices. Materials for large-scale structural use - wood, cement and concrete, and structural steel - cost between UK 50 and UK 500 (US 75 and US 750) per tonne. There are many materials which have all the other properties required of a structural material - nickel or titanium, for example - but their use in this application is eliminated by their price. 

Engineering design, then, involves many considerations (Fig. 1.7). The choice of a material must meet certain criteria on bulk and surface properties (strength and corrosion resistance, for example). But it must also be easy to fabricate it must appeal to potential consumers and it must compete economically with other alternative materials. In the next chapter we consider the economic aspects of this choice, returning in later chapters to a discussion of the other properties. 

These data, and the other properties of C M, suggest that bonding occurs by transfer of electrons from the alkali metal atoms to the conduction band of the host graphite. Consistent with... 

Anorin-38 has also shown an interesting effect as a multifunctional additive (a single additive to replace many of the conventional additives) for natural rubber (NR). It showed excellent blending behavior and compatibility with NR. Aorin-38 enhances the tensile properties and percent elongation, decreases fatigue, acts as an antioxidant and antiozonant, and positively affects many of the other properties, apart from acting as a process aid and a cure enhancer [183-186]. 

Referring to Tables 5-1 and 5-II, we find that both sodium chloride and copper have extremely high melting and boiling points. These two solids have little else in common. Sodium chloride has none of the other properties that identify a metal. It has no luster, rather, it forms a transparent crystal. It does not conduct electricity nor is it a good heat conductor. The kind of forces holding this crystal together must be quite different from those in metals. 

A typical example is as follows. Benzoic acid, C6H5COOH, is a solid substance with only moderate solubility in water. The aqueous solutions conduct electric current and have the other properties of an acid listed in Section 11-2.1. We can describe this behavior with reaction (42) leading to the equilibrium relation (43) ... 

The carboxyl group readily releases a proton, so it is an acid. For example, acetic acid dissolves in water and the solution is conducting, it turns blue litmus red, it is sour, and it shows all the other properties of an acid. The reaction... 

The bond orbitals of o, and relate to the other property of waves apart from the phase, that is, the amplitude. The bonding orbitals have large amplitudes on the low-lying atomic orbitals, i.e., on C of o, and on O of (Scheme 8). The antibonding orbitals have large amplitudes on the high-lying atomic orbitals. 

To see how pressure depends on the other properties, we consider the effect of changing one property at a time, holding the other properties constant. We analyze what happens to the molecular collisions as each property changes. 

Thus a good correlation between conversion yield and one of these properties obviously implies a similar correlation with the other property. The correlations between the volatile matter yield and the reactive maceral content and between the H/C atomic ratio and the reactive maceral content are not statistically significant. 

The best cure for a rubber product is always a compromise, but optimum cure may be defined as that time of cure necessary to bring a preselected property of the vulcanisate to near maximum (or minimum) value, at the same time ensuring that the other properties are satisfactory. All the physical properties of a rubber do not reach their optimum values at the same time of cure, and therefore the time must be selected so that the properties are near their optima, the most weight being given to the property considered most important. 

Currently available flame retardants must often be employed at concentrations at which they have adverse effects on the other properties of flame-retarded plastics or textiles. 

Some of the other properties of interest for fire hazard assessment cannot be measured with RHR calorimeters. They include flame spread, limiting oxygen index (LOI, or simply oxygen index, 01 both names have been used, but the author s preferred nomenclature is the one used here) and fire endurance. 

Metallic solids have metal atoms occupying the crystal lattice held together by metallic bonding. In metallic bonding, the electrons of the atoms are delocalized and free to move throughout the entire solid. This explains the electrical and thermal conductivity as well as many of the other properties of metals. 

IE s on some of the other properties of water are shown in Table 5.9. Many properties (like the enthalpies of phase change, triple points, etc.) are closely related to VP and can be interpreted similarly. Molar volume isotope effects are interesting and are discussed in Chapters 12 and 13. In the low temperature liquids... 

Specific grades of carbon and steel fibres are especially marketed as additives for conductive plastics allowing resistivities of roughly 10 ohm.cm to be obtained. The other properties of the final material - colour, modulus, impact strength. .. are modified. Carbon fibres have a large reinforcing effect. 

The matrix is the most important parameter in determining the other properties o thermal behaviour, durability, chemical and fire resistance... 

An equation of state for the vapor is needed to be able to calculate density from the pressure or temperature, lowing any one property (T, P, or pj pins down all the other properties since there is only one component, and two pMses are present in the tank. The perfect-gas law is used. 

Toxicologists have begun to understand how the chemical structure and some of the other properties of these chemicals contribute to their carcinogenicity. One important part of the effort to reduce reliance upon animal testing involves further validation of the use of chemical structure information along with other properties of a chemical - its... 

---