Expanding and Fusing

The catalyst was reformulated by Alwin Mittasch, who synthesized some 2500 different catalysts and performed more than 6500 tests. They arrived at a triply promoted catalyst consisting of a fused iron catalyst, with AI2O3 and CaO as structural promoters and potassium as an electronic promoter. The process was first commercialized by BASF, with the first plant located in Oppau in Germany producing 30 tons per day in 1913. The plant initially produced ammonium sulfate fertilizer, but when the First World War broke out it was redesigned to produce nitrates for ammunition. The plant was expanded and in 1915 it produced the equivalent of 230 tons ammonium per day. 

This composite material includes a PP moulded body having a particular melting point and a foamed body of expanded particles fuse-bonded to the body, which is... 

Fifteen to twenty billion years ago, the universe arose as a cataclysmic eruption of hot, energy-rich subatomic particles. Within seconds, the simplest elements (hydrogen and helium) were formed. As the universe expanded and cooled, material condensed under the influence of gravity to form stars. Some stars became enormous and then exploded as supernovae, releasing the energy needed to fuse simpler atomic nuclei into the more complex elements. Thus were produced, over billions of years, the Earth itself and the chemical elements found on the Earth today. About four billion years ago,... 

Fused-ring cyclopropylchlorocarbenes have been shown to ring expand to fused-ring chlorocyclobutenes with activation energies of 3-4 kcal mol-1 and activation entropies of ca —20 e.u., values that are similar to those observed for the parent cyclopropy-lchlorocarbene (Scheme 66).102 Carbon tunnelling is considered to be unimportant at low temperatures. 

Moldable beads are produced by suspension polymerization, swelling with pentane, warming to soften and pre-expand the beads, pouring them into a mold, and steaming to expand them fully, soften them, and fuse them together into a finished product. This produces drinking cups, molded packaging, board stock, and display and novelty products. 

The first of these processes took place in the first minutes following the Big Bang. The expanding cloud cooled enough for hydrogen atoms to form and for a series of nuclear reactions to occur. In each of these reactions, very high-velocity particles collided and fused to produce a new and larger nucleus ... 

Volume 90 of Advances in Heterocyclic Chemistry contains four chapters and the indexes. The book commences with Part II of Applications of Microwave Irradiation for Accelerating Reactions in Heterocycles. This continues Part I, which was published in Volume 88 of Advances in Heterocyclic Chemistry in 2005. Whereas Part I dealt with 3-, 4- and 5-membered heterocycles, the present Part II deals with 6-and 7-membered and spiro and fused heterocycles. Parts I and II have both been contributed by E. S. H. El Ashry, A. A. Kassem and E. Ramadan of Alexandria University, Egypt, and make available the large amount of recent work in this expanding area. 

On the other hand, PAI foams can be produced intentionally. For example, satisfactory foam structure and properties can be obtained by heating a commercial Torlon PAI powder in a closed mold to above glass transition temperatures for a time sufficient to soften and fuse the particles. Then, absorbed volatiles expand the polymer and fill the mold. The residence times range from several minutes to several hours. After heating. 

When the beads are heated in steam (or expanded ), the pentane volatilizes to expand the beads into a thermoplastic foam. These foam beads are subsequently packed into molds and fused by heat into the shape desired. The EPS can also be extruded into sheets and thermoformed into products such as meat trays and plates. EPS has good thermal insulation and shock-absorbing properties. 

In an effort to overcome steric interactions due to -substituents in cyclotetra(2,3-thienylene)s 4.6 (see above), Marsella et al. synthesized expanded thiophene-fused didehydro [12]annulene 4.32, which incorporated two additional ethynylene groups between the -positions of the cycUc stmcture (Scheme 1.44) [408]. Regiospeciflc halogenation of a 2,2 -bithiophene and Sonogashira-type cross-coupling with the ethynylated counter part were key elements of the synthetic strategy, which was also used to prepare a further extended macrocycle 4.33 (Chart 1.54), profiting from quadrupolar interactions of the central phenylene units [409]. 

In 1789 Guyton de Morveau reported that all attempts to decompose carbonic acid gas (e.g. Achard s of passing it over fused nitre) had failed. Although Monge, and Van Marum and Landriani, had found that the gas expands and becomes combustible on sparking, the latter concluded that the result was due to moisture. In 1791 Smithson Tennant showed that carbon is formed when phosphorus is heated with powdered marble, and Pearson obtained carbon on heating sodium carbonate with phosphorus. 

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