Heat crystallization

On strongly heating crystals of tetrammine palladium chloride, [Pd (NH3)4 ] Cl2. H20, palladium in the form of a sponge or fine powder is obtained. 

Heat crystal, dip it into liquid pitch and cedar oil, and it will become chrysolith. 

There is presently no complete explanation of how the device works. There is evidently a reversible structural change in the filament, which may have as its origin either the high field, high current flow, or local heating. Crystallization of the filament has been ruled out for several reasons - for example this would not give a reversible effect. 

Recently, tetrafunctional initiators have also been introduced for styrenics. In 2001, Atofina Chemicals introduced a novel tetrafunctional initiator, Luperox JWEB50, developed specifically for the styrenics industry to produce high molecular weight, high-heat, crystal polystyrene with improved productivity in a cost-effective manner. JWEB50 is a room temperature stable, liquid peroxide with a half-life similar to those of currently used cyclic perketals, appropriate for use in mass polystyrene processes. A unique aspect of... 

Heating crystals of both in proximity on a hot stage leads to a solid-solid transformation of one, followed by melting of both. Also, if on continued heating, one form melts and then can be induced to solidify by seeding with the other form, and then melted upon further heating, then the two are polymorphs. 

Most simple halides, ionic or covalent, melt unchanged on heating. Crystal defects have been identified as being important in the decompositions of C0F3 [48] and Cdlj [49]. Barret [50] studied the decomposition of CuBrj - CuBr + /2BT2 and discussed the role of diffusion within the mass of reactant particles on the overall kinetic behaviour. HF.LiF and HF.NaF decompose [51] before melting, in a single... 

Figure 13-16 Sublimation can be used to purify volatile solids. The high vapor pressure of the solid substance causes it to sublime when heated. Crystals of purified substance are formed when the vapor is deposited to form solid on the cooler (upper) portion of the apparatus. Iodine, fy, sublimes readily, fy vapor is purple.

Heat crystal malt and water to 180°. Strain into the boiling kettle. Add malt extract and Cascade hops to kettle and bring to a boil. Let boil for 30 minutes and then add Irish moss. Fifteen minutes later, add cinnamon and yeast nutrient. Boil for 10 minutes, add the honey and 3/s ounce of Hallertauer hops. Two minutes before the end of the boil add % ounce Hallertauer hops. Cool with wort chiller, strain into carboy, and pitch yeast. Rack to the secondary fermenter after 2 weeks. Let ferment another 6 weeks. Prime with Vz cup corn sugar and bottle. 

White, very hygroscopic, granular or flaky powder dec above 250. Dissolves in water with evolution of a considerable amount of heat. Crystallizes from water with 6H20. Keep rightly closed. 

When a wet chip (typically 0.5% moisture) falls into the fluid bed, the surface moisture is rapidly evaporated. As the chip is then further heated, crystallization occurs. This amorphous-to-crystalline transformation of PET is an exothermic reaction and the heat given off is quite sufficient to raise the surface temperature of PET to above the softening point. If the chips are not moving as they do in the fully developed fluidized state, this will produce large solid lumps of agglomerated chips. 

When prepared by fusion of boric acid, boron oxide forms a very hard and tough mass that can be ground only with great difficulty. However, the anhydrous oxide can be obtained in a porous form by carefully heating crystallized boric acid in a vacuum. The resulting product can be powdered readily. 

Form II could also be obtained by kneading or vapor digestion (Scheme 3). Both Forms I and II convert to Form III at high temperature. Form II is the thermodynamically stable form at room temperature, while Form I is a metastable form. Form III can also be prepared by heating crystals of Form II or Form I. Crystals of Form III, once formed, can be cooled down to room temperature. Kneading of Form III with a drop of water affords rapid and complete transformation into Form II. 

Comparison of Physical Properties of High Heat Crystal Poly-PMS and Polystyrene... 

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