Aluminum compounds, and

Sohd sorbent materials have the abiUty to adsorb water vapor until an equiUbrium condition is attained. The total weight of water that can be adsorbed in a particular material is a function of the temperature of the material and of the relative humidity of the air (see Adsorption). To regenerate the sorbent, its temperature must be raised or the relative humidity lowered. The sohd sorbents most commonly used are siUca (qv), alumina (see Aluminum compounds), and molecular sieves (qv). 

Dicyclopentadiene is also polymerized with tungsten-based catalysts. Because the polymerization reaction produces heavily cross-Unked resins, the polymers are manufactured in a reaction injection mol ding (RIM) process, in which all catalyst components and resin modifiers are slurried in two batches of the monomer. The first batch contains the catalyst (a mixture of WCl and WOCl, nonylphenol, acetylacetone, additives, and fillers the second batch contains the co-catalyst (a combination of an alkyl aluminum compound and a Lewis base such as ether), antioxidants, and elastomeric fillers (qv) for better moldabihty (50). Mixing two Uquids in a mold results in a rapid polymerization reaction. Its rate is controlled by the ratio between the co-catalyst and the Lewis base. Depending on the catalyst composition, solidification time of the reaction mixture can vary from two seconds to an hour. Similar catalyst systems are used for polymerization of norbomene and for norbomene copolymerization with ethyhdenenorbomene. 

Dimersol A family of processes for dimerizing single or mixed olefines, catalyzed by mixtures of trialkyl aluminum compounds and nickel salts. Developed by IFP and first commercialized in 1977 by 1997 it was used in 26 plants. 

Terpolymers of CO, C2H4 and propylene have been prepared using Ziegler-Natta type catalysts consisting of a combination of alkyl aluminum compounds and vanadium oxyalkoxides47>. The same procedure was also used to incorporate methyl vinyl ketone as the fourth component in the polymers. 

Weberg and Berstad 1986 Yokel and McNamara 1988). The effect has been shown with a variety of aluminum compounds and several forms of citrate in both experimental and clinical studies. The combination of citrate and aluminum has been responsible for a number of deaths in uremic patients, and the clinical implications of the interaction has led some investigators to advise against concomitant exposure to aluminum and citrate in any form (e.g., antacids and orange juice), especially to patients with impaired renal function. As discussed in Sections 2.3.1.2 and 2.4.1, citrate complexes with aluminum to form a species that is particularly bioavailable in the near-neutral pH conditions of the intestines. 

The precipitate prepared at 80° C. at about the stoichiometric AlEta/TiCE ratio of H has a reddish-brown color, and, according to x-ray analysis, consists of 3-TiCla, whereas the product prepared at 170° C. at the same Al/Ti ratio has a purple color and the structure of 7-TiCE (4, 24, 26). Analysis further showed that the TiCE thus formed contains an appreciable amount of aluminum compounds, and if prepared at 80° C., also some ethyl groups. These aluminum compounds, which apparently consist mainly of A1CE, and possibly of some AEEtCE, are taken up in the crystal lattice of the TiCE since they could not be removed by washing and hardly show up in the x-ray diagram (4, 24). About one out of every six titanium atoms is replaced by aluminum in the 80° C. solid reaction product (4), whereas in the 170° C. product, this... 

The filtrate obtained after collecting the crude product contains highly reactive alkyl aluminum compounds, and contact with water should be avoided. The alkyl aluminum compounds may be decomposed by the dropwise addition of 200 ml. of ethanol to the cooled solution followed by the cautious addition of water. 

Tin-aluminum exchange has been used to prepare bidentate aryl aluminum compounds and aluminoles as illustrated in equations (20) and (21)." ... 

SAFETY PROFILE A poison. Spontaneously flammable in air. Explodes in oxygen with traces of water. Incompatible with alkenes and water. See also ALUMINUM COMPOUNDS and BORON COMPOUNDS. 

ACGIH TLV TWA 2 mg(AI)/m3 SAFETY PROFILE Mildly toxic by inhalation. See also ALUMINUM COMPOUNDS and CHLORIDES. Ignites spontaneously in air. When heated to decomposition it emits toxic fumes of Cl". 

The combined use of a wide variety of tri alkyl aluminum compounds and alkylidene iodide serves as a highly convenient and versatile method for cyclopropanation of simple olefins under mild conditions. For example, treatment of 1-dodecene with CH2I2/R3AI (R = Me, Et, i-Bu) in dichloromethane at room temperature for 3-8 hr gave decylcyclopropane. in 96-98 6 yields. 

Motivated by the fact that polyolefins are stabilized using piperidine derivatives that can leach with time, the copolymerization of a-olefins with polymerizable piperidine derivatives was investigated. Hindered vinyl piperidines (e.g., Pip-I) can complex with aluminum compounds and incorporate into copolymers with propylene using commercial TiCh/MgCF Ziegler—Natta catalysts. ... 

In particular, ILs with the liquid phase ranging down to —80°G can be prepared with a relatively low viscosity. The Lewis acidity of these salts can be modulated by the relative amount of the aluminum compound and is usually expressed by the molar fraction (x) of the aluminum compound." Gonventionally, when x = 0.5 the mixture is called... 

In literature data there is an example of effective modification of organicaluminum catalysts by their combination with ethers [175]. Application of Al(i-C4H9)Cl20R2 provides decreasing of pentadiene-1,3 oligomerization rate and elimination of gel formation reaction [240]. Complex formation of Al(i-C4H9)Cl2 with ethers leads to the decrease of Lewis acidity of aluminum compound and value of acidic force decrease is determined by ethers electron-donor properties. In particular,... 

An aluminum eontaining photoinitiation eatalyst was reported by Hayase and eoworkers It eonsists of the aluminum compound and o-nitrobenzyl triphenylsilyl ether. The o-nitrobenzyl triphenylsilyl ether photo decomposes to form triphenylsilanol ... 

The manufacture of paper and allied products involves the preparation of wood and other raw materials, separation and recovery of cellulose fibers, and blending of the fibers with proper additives to produce furnish , which is formed into paper. The additives include sizing materials such as alum and resins, sodium aluminate, and wax emulsions synthetics, such as acrylics, isocyanates, and fiuocarbons and fillers such as clays, calcium carbonate and sulfate, talc, barium sulfate, aluminum compounds, and titanium oxide. When fillers are used, retention aids (starches or synthetic resins) are added to increase the retention of the filler. 

The precise mechanism and the localization of the absorption for orally taken aluminum are not known so far. It is assumed, however, that the aluminum is absorbed in the stomach and the duodenum, possibly in the proximal jejunum as well. The absorbed amount depends on the solubility of the aluminum compound and the respective gastrointestinal pH level. In addition, iron and fluorine increase the enteral absorption. Furthermore, the aluminum intake might be influenced by the parathyroid hormone and vitamin D. The daily aluminum intake via nutrition depends on eating habits and is estimated at an average of 5-10 mg/day less than 1% of this amount is absorbed. 

---