Softening temperature range

Refractoriness. Most refractories are mixtures of different oxides, sometimes with significant quantities of impurities. Thus, they do not have sharp melting points but a softening range. Refractoriness is the resistance to physical deformation under the influence of temperature. It is determined by the pyrometric cone equivalent (PCE) test for aluminosiHcates and resistance to creep or shear at high temperature (see Analytical methods). 

Pontia.na.k. This resin is a copal and is similar to the alcohol-soluble Manilas. It is partially fossilized, so it melts at a higher temperature. Softening points range from 99—135°C, and acid numbers from about 112—120. Pontianak [9000-14-0] is used in specialty coatings and adhesives. 

Softening range Temperature range in which a plastic transforms from a rigid solid to a soft state. 

Laminate expansion/contraction characteristics were determined with a DuPont Model 942 TMA. In this test the movement of an 0.38 cm diameter, hemispherical-tipped quartz probe resting on the specimen was monitored as the specimen was heated from room temperature through its softening range. 

Softening range data can serve as guides to proper temperatures for melt fabrication, such as melt pressing, melt extruding, and molding. They also are related to the product s thermal stability. 

PYROMETRIC CONES. Small cones that differ in the temperatures at which they soften on heating. They are made of clay and other ceramic materials and are used in the ceramic industries to show furnace temperatures within ranges. In practice, three or four of the cones which... 

With crystalline types [not amorphous (Chapter 1)], melt leaving the die (and moving to a ring-shaped zone where the film approaches its diameter) changes from a hazy to a transparent (amorphous) condition. The level at which this transition occurs is the frost line. This zone is characterized by a frosty appearance to the film caused by the film temperature falling below the softening range of the plastic. 

A glass object can be used for indefinite periods below its annealing temperature but only for very short intermittent periods at the high end of its softening range. Fused silica is obviously very useful for high-temperature apparatus and Vycor, which contains a few percent of other oxides, is almost as good. At elevated temperatures fused quartz will devitrify, i.e., ciystallize and become opaque. 

A typical DSC plot of the rate of heat absorption versus temperature Is shown for poly(llmonene oxide) In Figure 6. An endothermic transition corresponding to an enthalpy change of 0.3 cal g was observed between 65.2 and 84.5 C, the peak being at 74.2 C. A similar plot was obtained for poly(a-plnene oxide), the peak occurring at 81.3 C with a AH of 0.13 cal g measured between 78.3 and 84.3°C. Ruckel et al. (14) have reported very similar softening ranges of 67-80 and 65-80 C for the catalytlcally-prepared poly(o-plnene oxide) and poly(B plnene oxide). 

Melting range can have a profound impact on performance as liquid formation can lead to shrinkage of the refractory, reaction with the contained product, high temperature softening and flow (especially under pressure), etc. The viscosity behavior of the liquid itself is also important as highly viscous fluids behave very similarly to solids so considerably more can be present before problems occur. 

During application of refractory oxides, melting range is typically more important than melting temperature. Softening point is defined as the temperature at which a... 

Resin Collective term for solid and viscous, organic, noncrystalline products with more or less broad dispersion of the molar mass. Usually, resins have a melting or softening range, are brittle in the solid state and break in a clam-like manner. They tend to flow at room temperature. Apart from resins as additives to adhesives, some adhesive raw materials, for example, epoxy resins, phenol resins, polyester resins bear this name, too. 

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