Other Physical Properties

Other physical properties such as the smoke, flash, and fire points of oils and fats are measures of their thermal stability when heated. The smoke point is important for the oils and fats used for deep-frying. The flash point and fire points are a measure of residual solvent in crude and refined oils and are also a safety requirement. 

Properties Rapeseed oil Peanut oil Cottonseed oil Soybean oil Sunflower oil Coconut oil Palm oil Olive oil Beef tallow Lard 

Extractives have various effects on other physical properties. Extractives with special characteristics, such as quinones, seriously affect the adhesive and finishing qualities of the wood (9.4.2). The nonpolar extractives with a lower oxygen content such as terpenoids, oils, fats, and waxes, affect the hydroscopicity, and permeability. This causes trouble in adhesion and finishing by the inhibition of the wetting of the wood. On the other hand, since these nonpolar extractives have high caloric value, they increase the flammability of wood and make these woods valuable as fuel. 

The roles of these various wood properties and their influences in the utilization of wood are discussed in detail in the Wood Handbook (34). 

1 Abe Z, Minami K 1976 111 smell from the wood of Gonystylus bancanus (Miq.) Kurz. I. Mokuzai Gakkaishi 22 119-120 

3 Bentley K W 1960 The chemistry of natural products. IV. The natural pigments. Interscience New York, 74-92 

A few applications of isobenzofurans have been reported in the patent literature, e.g., for the preparation of polymers [90JAP(K)02/75625 90JAP(K)02/263824], for electrophotographic photoreceptors [88JAP(K)-63/60453 93JAP(K)04/212166, 93USP5250395 94JAP(K)05/158620, 

Wittig, E. Knauss, and K. Niethammer, Justus Liebigs Ann. Chem. 630, 10 (1960). 

Albert, Heterocyclic Chemistry, 2nd ed. Athlone Press, London, 1968. 

Cignarella, A. Saba, and G. G. Gallo, Gazz. Chim. Ital. 101, 508 

Saito and Y. Omura, Nagoya Kogyo Daigaku Gakuho 29, 197 

A correlation has been made between the Hammett substituent constants for 9-substituted benzo[h]quinohzinium salts and the rate of cycloaddition113 this, and the measured Arrhenius parameters for the same 

Density values (g/cm ) of different PET grades are reported in Table 4.2. 

With the introduction of automated helium pycnometer, true densities of raw materials can be determined with ease and at a high degree of accuracy. The true density can serve to assure the formulator the identity of the material and sometimes reveal the state of raw materials, like partial changes of a powder from anhydrous to hydrated form. 

The drum could be programmed to rotate at user-defined rates. A metal mesh collar was fitted onto the inner circumference of the drum to prevent the sliding of powder particles down the circumferential wall instead of avalanching. Test powders should be sieved before being poured into the sample drum. 

Analysis should be performed at a range of drum speeds in order to determine the flow index, as calculated by the equation described as follows  

Shear studies of powder bed can also be carried out to evaluate the cohesiveness of powders. There are many variations of shear cells for evaluation of powder cohesiveness. 

The change in the packing properties of powders under pressure is used to study the compactability of powders. This study can be made using compression punches attached to pressure transducers (24). The force exerted and the displacement can be utilized to calculate useful parameters for assessing the compactability of a powder or powder mix. 

One of the advantages of gas hydrates is the significant volume reduction compared with the original gaseous phase. For example, if all cavities of si are occupied, one volume of hydrate may contain 184 volumes of gas at standard temperature and pressure. Specifically, it is estimated that the maximum density of CO2 hydrates is 

resulting in a density of 1.12 g/cm. The main uncertainty of the density estimated this way arises from the cage occupancy, which may be affected by the pressure. Generally, the density of CO2 hydrates formed under deep sea conditions is slightly higher than that of hquid CO2 (around 1.05 g/cm ) tmder the same conditions. 

Monocrystals exhibit n- and p-type conductivity with thermoelectric powers a= -317 and +217 iV/K, respectively. The electrical resistivity is -10 Q-cm. The crystals show a rectifying effect, Yarembash etal. [7]. 

The diamagnetic susceptibility x of LaSe2 was measured at 88 to 440 K. Due to -0.3% paramagnetic impurities, x varies linearly with ITT. The extrapolation to zero gives x(0) = -24x10 cm /mol. According to the additivity rule, x(0) Xdia should be -122 x 10 cm /mol if available data for La and Se are used. The difference corresponds to a paramagnetic Van Vleck contribution. This arises from deformation of the ions due to mixed ionic-covalent bond character, Lashkarev, Savitskii [14]. 

The compound is black [8] or grayish black with a greenish tinge [6]. The X-ray L, absorption spectrum of LaSe2 shows a principal maximum at 5488.3 eV. This corresponds to a displacement by -0.8eV relative to the La203 maximum, Vainshtein etal. [16]. 

The reaction of LaSe2 with H2 at 350 to 360°C gives a black material and near 900°C the usual brick red form of La2Se3. The same forms are obtained in an inert atmosphere at 150 to 

200°C higher temperatures. Heating in an H2Se current to 1200°C also reduces the Se content to a limiting 60 at.% (La2Se3), Obolonchik, Mikhlina [1]. 

Considerations on the Polarographic Behavior of Organometallic Compounds of the Type R. Me -X, Ann. Chim. [Rome] 41 [1951] 207/20. 

Cresswell, W. T., Leicester, J., Vogel, A. I., Bond Refractions for Compounds of Tin, Silicon, Lead, Mercury, and Germanium, Chem. Ind. [London] 1953 19. 

Dibeler, V. H., Mass Spectra of the Tetramethyl Compounds of Carbon, Silicon, Germanium, Tin, and Lead, J. Res. Natl. Bur. Std. 49 [1952] 235/9. 

Lutskii, A. E., Molecular Constants and the Physical Properties of Liquids. The Boiling Points, Zh. Fiz. Khim. 30 [1956] 396/406. 

The activation energy of the viscous flow, E = 8.4 kj/mol, and the free energy of flow activation, E = 13.7 kJ/mol were calculated. Parameters to characterize the surface layer are as follows excess surface entropy, 85= -0.090 J mor surface enthalpy, Hs = 54.9 J/mol at 20 C, and free surface energy, Gs = 81.4 J/mol at 20 °C [16]. 

The diamagnetic susceptibility, Xpb- Pb(C2H5)4 Is estimated to be -47.5x10 [5], — 44.3x10 cm /mol [4, 6, 8] see also [1]. The contribution of the individual bonds (Xc-Pb= -12.8X 10 ) to the total diamagnetic susceptibility is calculated in [10]. The total ionization cross section and polarizability of M(C2Hs)4 (M = Si, Ge, Sn, Pb) show a good linear relationship [12]. 

Values have been calculated for the nonlinear Index of refraction (arising from molecular reorientation and local spatial redistribution), the threshold power for self-focusing in the liquid (over periods so short that macroscopic density changes do not have time to take place), and the nonlinear index of Debye (for molecular reorientation alone) [11]. 

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Compilation of azeotropic data as well as other physical properties including melting and boiling points. 

For other physical properties, the specification differences between diesel fuel and home-heating oil are minimal. Note only that there is no minimum distillation end point for heating oil, undoubtedly because tbe problem of particulate emissions is much less critical in domestic burners than in an engine. 

The immobility of the surface atoms of a refractory solid has the consequence that the surface energy and other physical properties depend greatly on the immediate history of the material. A clean cleavage surface of a crystal will have a different (and probably lower) surface energy than a ground, abraded, heat-treated or polished surface of the same material. 

D. Dependence of Other Physical Properties on Surface Energy Changes at a Solid Interface... 

These fascinating bicontinuous or sponge phases have attracted considerable theoretical interest. Percolation theory [112] is an important component of such models as it can be used to describe conductivity and other physical properties of microemulsions. Topological analysis [113] and geometric models [114] are useful, as are thermodynamic analyses [115-118] balancing curvature elasticity and entropy. Similar elastic modulus considerations enter into models of the properties and stability of droplet phases [119-121] and phase behavior of microemulsions in general [97, 122]. 

Location of the compound within a class (or homologous series) of compounds. Reference to the literature or to tables of the physical properties of the class (or classes) of organic compounds to which the substance has been assigned, will generally locate a number of compounds which boil or melt within 6° of the value observed for the unknown. If other physical properties e.g., refractive index and density for a hquid) are available, these will assist in deciding whether the unknown is identical with one of the known compounds. In general, however, it is more convenient in practice to prepare one, but preferably two, crystalhne derivatives of the substance. 

Preparation of derivatives. If two distinct crystaUine derivatives of the unknown have the same melting point (or other physical properties) as those of the compound described in the hterature (or in the tables), the identity of the two compounds may be assumed. Further... 

The production of both an alcohol and the sodium salt of an acid might easily be confused with the hydrolysis products of an ester (in the above instance benzyl benzoate). Such an error would soon be discovered (e.g., by reference to the b.p. and other physical properties), but it would lead to an unnecessary expenditure of time and energy. The above example, however, emphasises the importance of conducting the class reactions of neutral oxygen-containing compounds in the proper order, viz., (1) aldehydes and ketones, (2) esters and anhydrides, (3) alcohols, and (4) ethers. 

Most of the techniques described in this Chapter are of the ab initio type. This means that they attempt to compute electronic state energies and other physical properties, as functions of the positions of the nuclei, from first principles without the use or knowledge of experimental input. Although perturbation theory or the variational method may be used to generate the working equations of a particular method, and although finite atomic orbital basis sets are nearly always utilized, these approximations do not involve fitting to known experimental data. They represent approximations that can be systematically improved as the level of treatment is enhanced. 

The elastic and viscoelastic properties of materials are less familiar in chemistry than many other physical properties hence it is necessary to spend a fair amount of time describing the experiments and the observed response of the polymer. There are a large number of possible modes of deformation that might be considered We shall consider only elongation and shear. For each of these we consider the stress associated with a unit strain and the strain associated with a unit stress the former is called the modulus, the latter the compliance. Experiments can be time independent (equilibrium), time dependent (transient), or periodic (dynamic). Just to define and describe these basic combinations takes us into a fair amount of detail and affords some possibilities for confusion. Pay close attention to the definitions of terms and symbols. 

Oriented polypropylene film (OPP) may be classified as heat-set and non-heat-set, blown and tentered, coextmded and coated. Orientation improves the cold-temperature resistance and other physical properties. Heat-set biaxially oriented polypropylene film (BOPP) is the most widely used protective packagiag film ia the United States. It is used to wrap bakery products, as lamination pHes for potato and com chips, and for pastas and numerous other flexible pouch and wrapping appHcations. Nonheat-set OPP is used as a sparkling, transparent shrink-film overwrap for cartons of candy. 

The thermal conductivity of gas-phase deuterium is about 0.73 times that of gas-phase hydrogen. This thermal conductivity difference offers a convenient method for analysis of H2—D2 mixtures. Other physical properties of D2, T2, HD, DT, and HT are Hsted in the Hterature (60). 

Enclosure also changes the redox properties of a compound, its color, and other physical properties (1,2). On this basis nonlinear optical materials, luminescence markers, controlled light switches, and other high-tech devices might be designed and prepared (15,17,137). 

Physical Properties. The absorption of x-rays by iodine has been studied and the iodine crystal stmcture deterrnined (12,13). Iodine crystallizes in the orthorhombic system and has a unit cell of eight atoms arranged as a symmetrical bipyramid. The cell constants at 18°C (14) are given in Table 1, along with other physical properties. Prom the interatomic distances of many iodine compounds, the calculated effective radius of the covalently bound iodine atom is 184 pm (15). 

Isophorone. Isophorone (3,5,5-trimethyl-2-cyclohexen-l-one) is a cycHc a,P-unsaturated ketone derived from the trimeri2ation of acetone. It has a light yellow color and a disagreeable camphoraceous odor. It has the tendency to discolor and form residues on prolonged storage. Isophorone is completely miscible with organic solvents, and other physical properties are Hsted ia Table 1. 

Penta.nedione, 2,4-Pentanedione [123-54-6] (acetylacetone) is the lowest member of the aUphatic 1,3-diketones and is a colorless Hquid with a mild ketone-like odor. It is completely miscible with organic solvents other physical properties ate shown in Table 1. 

Bond dissociation energies (BDEs) for the oxygen—oxygen and oxygen— hydrogen bonds are 167—184 kj/mol (40.0—44.0 kcal/mol) and 375 kj/mol (89.6 kcal/mol), respectively (10,45). Heats of formation, entropies, andheat capacities of hydroperoxides have been summarized (9). Hydroperoxides exist as hydrogen-bonded dimers in nonpolar solvents and readily form hydrogen-bonded associations with ethers, alcohols, amines, ketones, sulfoxides, and carboxyhc acids (46). Other physical properties of hydroperoxides have been reported (46). 

Infrared, uv, nmr spectra (66), and photoelectron spectra have been reviewed (67). Physical properties of siHcon peroxides are summarized in Reference 43. Other physical properties, eg, dipole moments, dihedral angles, and heats of combustion ate Hsted in Reference 68. The oxygen—oxygen bond strengths of various diaLkyl peroxides have been reported (69). 

Process Measurements. The most commonly measured process variables are pressures, flows, levels, and temperatures (see Flow LffiASURELffiNT Liquid-levell asurel nt PressureLffiASURELffiNT Temperaturel asurel nt). When appropriate, other physical properties, chemical properties, and chemical compositions are also measured. The selection of the proper instmmentation for a particular appHcation is dependent on factors such as the type and nature of the fluid or soHd involved relevant process conditions rangeabiHty, accuracy, and repeatabiHty requited response time installed cost and maintainabiHty and reHabiHty. Various handbooks are available that can assist in selecting sensors (qv) for particular appHcations (14—16). 

Crystals of the dihydrate belong to the monoclinic system and have lattice parameters a = 659 pm, b = 1020 pm, and c = 651 pm. The anhydrous crystal belongs to the cubic system, a = 596 pm. Other physical properties of the anhydrous salt are Hsted iu Table 1. The anhydrous salt is hygroscopic but not dehquescent. 

Descriptions of sulfuric acid analytical procedures not specified by ASTM are available (32,152). Federal specifications also describe the requited method of analysis. Concentrations of 78 wt % and 93 wt % H2SO4 are commonly measured indirectly by determining specific gravity. Higher acid concentrations are normally determined by titration with a base, or by sonic velocity or other physical property for plant control. Sonic velocity has been found to be quite accurate for strength analysis of both filming and nonfuming acid. 

Chemical Intermediates and Reagents. Table 1 Hsts some chemical intermediates and synthesis reagents containing bromine. The references cited in the table generally give a method of synthesis and often some physical properties. Other physical properties are also available (194—196). 

Progressive chlorination of a hydrocarbon molecule yields a succession of Hquids and/or soHds of increasing nonflammability, density, and viscosity, as well as improved solubiUty for a large number of inorganic and organic materials. Other physical properties such as specific heat, dielectric constant, and water solubihty decrease with increasing chlorine content. 

AHyl chloride is a colorless Hquid with a disagreeable, pungent odor. Although miscible in typical compounds such as alcohol, chloroform, ether, acetone, benzene, carbon tetrachloride, heptane, toluene, and acetone, aHyl chloride is only slightly soluble in water (21—23). Other physical properties are given in Table 1. 

Oxirane (1) and methyloxirane (3) are miscible with water, ethyloxirane is very soluble in water, while compounds such as cyclopentene oxide and higher oxiranes are essentially insoluble (B-73MI50501) (for a discussion of the solubilities of heterocycles, see (63PMH(l)l77)). Other physical properties of heterocycles, such as dipole moments and electrochemical properties, are discussed in various chapters of pmh. The optical activity of chiral oxiranes has been investigated by ab initio molecular orbital methods (8UA1023). 

McGraw-HiU, New York, 1964 and Bretsznajder, Prediction of Transport and Other Physical Properties of Fluids, Pergamon, New York, 1971, may be found useful. The most exhaustive recent compilation for gases is by Mason and Marrero,y. Phys. Chem. Ref Data, 1 (1972). Unfortunately, the Mason and Marrero work cites only equations and equation constants and not direc t tabulations. For these, tne Landolt-Bornstein series is suggested. 

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