Effect of temperature on properties

The effect of temperature on properties can be seen in Figure 2, which shows the effect on modulus of increasing temperature of unmodified and glass-reinforced nylon-6,6. Impact strength, however, shows a steady increase with temperature as it does with moisture. 

Figure 1 Effect of temperature on properties of glass-filled PPS...

Mackenzie J.D., Huang Q., Rubio-Alonso F., Kramer S.J. Effects of temperature on properties of Ormosils. In Better Ceramics Through Chemistry VII Organic/Inorganic Hybrid Materials, Materials Research Society Symposium Proceedings, Vol. 435. Materials Research Society, Pittsburgh, PA, USA, 1996,pp. 229-236... 

Fig. 12. Effect of temperature on the stress—mpture properties of three niobium alloys coated with a siUcide at A, 1205°C, and B, 1315°C (B) represents all...

Fig. 3. Effect of siHcon on properties of iron (10). = Curie temperature = magnetocrystaUine anisotropy constant. To convert T to G, multiply by...

The effect of temperature on PSF tensile stress—strain behavior is depicted in Figure 4. The resin continues to exhibit useful mechanical properties at temperatures up to 160°C under prolonged or repeated thermal exposure. PES and PPSF extend this temperature limit to about 180°C. The dependence of flexural moduli on temperature for polysulfones is shown in Figure 5 with comparison to other engineering thermoplastics. 

The mechanical properties of wood tend to increase when it is cooled and to decrease when it is heated (6,18). If untreated wood heated in air is not exposed to temperatures of more than - 70° C for more than about 1 year, the decrease in properties with increasing temperature is referred to as immediate or reversible ie, the property would be lower if tested at the higher temperature but would be unchanged if heated and then tested at room temperature. The immediate effect of temperature on strength and modulus of elasticity of clear wood, based on several different loading modes, is illustrated in Figures 4—6 (6). 

Fig. 5. The immediate effect of temperature on strength properties of clear wood, expressed as percentage of value at 20°C. Trends illustrated are composites from studies on three strength properties modulus of mpture in bending, tensile strength perpendicular to grain, and compressive strength parallel to grain. VariabiUty in reported results is illustrated by the width of the bands. MC = moisture content.

At room temperature and atmospheric pressure ammonia is a colourless, alkaline gas with a pungent smell. It dissolves readily in water. Physical properties are summarized in Table 9.6. The effect of temperature on vapour pressure of anhydrous ammonia is shown in Figure 9.2. 

It follows that although the thermodynamic functions can be measured for a given distribution system, they can not be predicted before the fact. Nevertheless, the thermodynamic properties of the distribution system can help explain the characteristics of the distribution and to predict, quite accurately, the effect of temperature on the separation. 

Using the results calculated from the density data, the concentration of the individual components of the methanol/water mixture at different temperatures can be computed thus disclosing the effect of temperature on the elution properties of methanol/water mixtures. The results are shown in Figure 30. 

Thermal Properties. Before considering conventional thermal properties such as conductivity it is appropriate to consi r briefly the effect of temperature on the mechanical properties of plastics. It was stated earlier that the properties of plastics are markedly temperature dependent. This is as a result of their molecular structure. Consider first an amorphous plastic in which the molecular chains have a random configuration. Inside the material, even though it is not possible to view them, we loiow that the molecules are in a state of continual motion. As the material is heated up the molecules receive more energy and there is an increase in their relative movement. This makes the material more flexible. Conversely if the material is cooled down then molecular mobility decreases and the material becomes stiffer. 

K. Higashi, T.G. Nieh, and J. Wadsworth, "Effect of Temperature on the Mechanical Properties of Mechanically-Alloyed Materials at High Strain Rates," Acta Metall. Mater., 43 3275 (1995). 

Bianchi, G., Corguetti, A., Mazza, F. and Torchio, S., Electronic Properties of Oxide Films and Pitting Susceptibility of Type 304 Stainless Steel , Corros. Sci., 12, 495 (1972) Szkiarska-Smialowska, Z. and Mankowski, J., Effect of Temperature on the Kinetics of... 

Masuelli, Martin Alberto. Viscometric study of pectin. Effect of temperature on the hydrodynamic properties.. International Journal of Biolovical Macromolecules 48 (2011) 286-291. 

Hydrogen sulphide is used in the preparation of metal sulphides, oil additives etc., in the purification and separation of metals, as an analytical reagent and as raw material in organic synthesis. Physical properties are summarized in Table 8.11 and effects of temperature on vapour pressure are shown in Figure 8.4. 

It is a non-flammable colourless gas which is twice as dense as air, and slightly soluble in water, forming sulphurous acid. It is readily liquefied as a gas under its own vapour pressure of about 35psig (2.4 bar) at 21°C. Figure 8.5 depicts the effect of temperature on vapour pressure Table 8.12 lists the physical properties. Cylinders tend to be protected against over-pressurization by metal plugs melting at about 85°C. 

Liquid carbon dioxide produces a colourless, dense, non-flammable vapour with a slightly pungent odour and characteristic acid taste . Physical properties are given in Table 8.5 (see also page 277). Figure 8.1 demonstrates the effect of temperature on vapour pressure. 

The effect of temperature on the mechanical properties has definite place in specification of a material for any particular application. Some materials become dangerously brittle under arctic conditions, and all metals exhibit at elevated temperatures a phenomenon called creep. 

Li, J. and Carr, P.W., Effect of temperature on the thermodynamic properties, kinetic performance, and stability of polybutadiene-coated zirconia, Anal. Chem., 69(5), 837, 1997. 

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