Poly aluminium chloride

Passive oxidation of mine water from the Maude Mine removes up to 98% of the contained As through precipitation of ferrihydrite and scavenging of As from solution. The remaining arsenic in the water can be removed by the use of the coagulating agents poly-aluminium chloride or ferric chloride. 

Poly aluminium chloride (PAC), A1i3(OH)20(SO4)2-C1i5 Floe formed is more dense and faster settling than alum in some applications Not often used... 

In an attempt to lower the salt consumption and form larger agglomerates, a small amount of an adsorbing polymer (e.g. poly(aluminium chloride)) is also added to the thickener. 

Reduction of poly(vinyl chloride) with lithium aluminium hydride. 

Freeder, B. G. et al., J. Loss Prev. Process Ind., 1988, 1, 164-168 Accidental contamination of a 90 kg cylinder of ethylene oxide with a little sodium hydroxide solution led to explosive failure of the cylinder over 8 hours later [1], Based on later studies of the kinetics and heat release of the poly condensation reaction, it was estimated that after 8 hours and 1 min, some 12.7% of the oxide had condensed with an increase in temperature from 20 to 100°C. At this point the heat release rate was calculated to be 2.1 MJ/min, and 100 s later the temperature and heat release rate would be 160° and 1.67 MJ/s respectively, with 28% condensation. Complete reaction would have been attained some 16 s later at a temperature of 700°C [2], Precautions designed to prevent explosive polymerisation of ethylene oxide are discussed, including rigid exclusion of acids covalent halides, such as aluminium chloride, iron(III) chloride, tin(IV) chloride basic materials like alkali hydroxides, ammonia, amines, metallic potassium and catalytically active solids such as aluminium oxide, iron oxide, or rust [1] A comparative study of the runaway exothermic polymerisation of ethylene oxide and of propylene oxide by 10 wt% of solutions of sodium hydroxide of various concentrations has been done using ARC. Results below show onset temperatures/corrected adiabatic exotherm/maximum pressure attained and heat of polymerisation for the least (0.125 M) and most (1 M) concentrated alkali solutions used as catalysts. 

Military propellants are based on relatively powerful oxidisers and fuels of high calorihc value in order to develop an improved thrust or impulse. Thus the most commonly-used oxidisers are potassium perchlorate, ammonium perchlorate or more esoteric compounds such as hydrazinium nitroformate. Metallic fuels include aluminium, magnesium and beryllium, while binders are mainly hydrocarbons such as polybutadiene, polyisobutylene, polyurethane or poly(vinyl chloride) (PVC) as presented in Table 3.2. 

The alternative route to synthesis of poly(p-phenylene), which has been widely used, is the Scholl reaction5A), which involves direct oxidative elimination of two aryl hydrogen atoms with concomitant formation of a new carbon-carbon bond. This reaction occurs under Friedel-Crafts conditions and requires the presence of an appropriate oxidant to remove the hydrogen liberated in the coupling process. This route is typified by the Kovadk polymerization of benzene55) induced by aluminium chloride in the presence of stoichiometric amounts of Cu(II) chloride ... 

Other well-defined catalysts for epoxide polymerisations, containing an isolated metal atom, have been derived from the reaction of diethylaluminium chloride with a Schiffs base [37-40]. For instance, 2,2 -[(l / ,2/ )-1,2-cyclo-hexylenebis(nitrilomethylidene)]diphenolato aluminium chloride [(sal)AlCl] appeared to produce low molecular weight poly(propylene oxide) characterised by a narrow distribution of molecular weights [40] ... 

Pyrocatechol Violet (formula 4.16) is a popular reagent for determining aluminium [11,31,33-36]. The value of 8 is 6.3-10 at 580 nm (pH 6.5-7.2) [35]. A relatively small increase in sensitivity is observed in ternary systems with CTA, CP, or poly(vinylbenzyltriphenylphosphonium) chloride [37-39]. The ternary complex with Zephiramine can be extracted into CHCI3 or 1,2-dichloroethane (e 9-10 at 590 nm) [40]. The extractive (xylene) method with the use of tridodecylethylammonium bromide is of very high sensitivity (e = 1.7-10 at 613 nm [41]. Aluminium was also determined by the FIA technique using Pyrocatechol Violet [42]. 

Poly(2,5-dialkoxy-l,4-phenylene)s can also be made by oxidation of para-dialkoxybenzenes (Scheme 11). Thus, 1,4-dimethoxybenzene (23) can be polymerised with aluminium chloride and copper(II) chloride or iron(III) chloride. The polymer 24 is only soluble in sulfuric acid, however, and so not usable in LEDs [7]. Oxidation of 1,4-dibutoxybenzene (25) with iron(III) chloride by contrast gives a polymer 26 which is soluble in organic solvents [70,71]. 

Polymers from Thiophen Derivatives.—The bifunctionality of thiophen and its potential availability in large quantities at a low price has for many years attracted the interest of polymer chemists. However, progress has been slow. 2,5-Dichlorothiophen has been polymerized to a solid in 93% yield on treatment with aluminium chloride and cupric chloride in carbon disulphide. The product is believed to be poly-5-chloro-2,3-thienylene. Thiophen-2,5-dicarboxylic hydrazide was prepared by the reaction of thiophen-2,5-dicarbonyl chloride with the corresponding dihydrazide and then cyclodehydrated to poly-(thienylene-[2,5]-alt-l,3,4-oxadiazolylene-[2,5]-amer) (258) by polyphosphoric acid. This polymer could also be obtained directly from thiophen-2,5-dicarboxylic acid and hydrazine in oleum. The polymers produced were investigated in view of their thermal stability and as polymeric organic semiconductors. The same research... 

The majority of grafting from syntheses have been accomplished by converting polymeric halides into macro-initiators. Allyl halides provide suitably stable carbocation derivatives and consequently the partial dehydrohalogenation of poly(vinyl chloride) has been found to enhance the rate of styrene grafting in the presence of aluminium chloride. Similar sites available in chloroprene were activated by silver hexafluorophosphate to induce grafting of IBVE. Nitrosyl and... 

The cationic cyclization of polyisoprene with acid catalysts is well documented. The same reaction in polybutadienes requires much more severe conditions, higher temperatures and more acidic catalysts, and until recently has received much less attention. A cyclized polymer with a reduction of 35—40% of the initial unsaturation, can be prepared by treating cis-l,4-polybutadiene with an alkyl aluminium chloride-organic halide catalyst in xylene solution at >100 C."- Such polymers, containing polycyclic sequences apparently at random within the chains, have better skid resistance and tensile properties than the parent polymer. Cyclization has been reported to accompany other reactions in polydienes, for example the radiation-induced addition of carbon tetrachloride to 1,2-polybutadiene, and the direct addition of a o j unsaturated carboxylic acids (acrylic and cinnamic) to polydienes and polypentenamers. It is reported that the thermal isomerization of cis-transoidal poly(phenylacetylene) is accompanied by cyclization, and additionally chain scission and aromatization at temperatures >120°C. ... 

Aluminium chloride (AICI3) as the Lewis acid (catalyst) with cupric chloride (CuCb) as the oxidizing agent was the best catalyst-oxidant combination used by Kovacic et al. for the polymerization of benzene. Polymerization occurred under mild conditions (36-37°C, 15 minutes), with water as a co-catalyst, and the yield of poly-(p-phenylene) was found to depend on the aluminium chloride to cupric chloride ratio. 

In the first stage, a Friedel-Crafts reaction is carried out by treating benzene with ethylene in the liquid phase at 90—100°C at slightly above atmospheric pressure. The catalyst is aluminium chloride (with ethyl chloride as catalyst promoter). A molar excess of benzene is used to reduce the formation of poly ethylbenzenes the molar ratio of reactants is generally about 1 0.6. The reactants are fed continuously into the bottom of a reactor whilst crude product is removed from near the top. The product is cooled and allowed to separate into two layers the lower layer, which consists of an aluminium chloride-hydrocarbon complex, is removed and returned to the reactor. The remaining ethylbenzene is then separated by distillation from polyethylbenzenes and benzene, which are recycled. 

There is also evidence that commercial poly(vinyl chloride) is slightly branched. When the polymer is treated with lithium aluminium hydride a type of polyethylene is obtained, the infrared spectrum of which indicates about 20 branches per polymer chain. Branching occurs during polymerization by transfer of hydrogen from within the polymer to growing radicals. The most labile hydrogen atoms in poly(vinyl chloride) are those in the —CHCl— groups since the resultant free radical has resonance stability ... 

Direct Friedel-Crafts alkylation of ferrocene gives only low yields of mono- and poly-alkylated ferrocenes. Better yields are obtained using aluminium chloride and olefins under pressure ... 

Unlike all the other classes described above these adhesives do not typically undergo hardening after they have been applied to the substrate surfaces and the joint formed. They are generally in the form of an already polymerized adhesive which is coated onto one or both sides of a backing material such as cellulose, polyester, foamed polyurethane, poly(vinyl chloride), aluminium or lead. The adhesive is usually permanently tacky and based upon natural rubber, styrene-butadiene rubber (random and, more recently, block copolymers), polyisobutylene or an acrylic polymer, but as usual is a complex formulation containing many additives. The adhesive is formulated so that it flows sufficiently, when hand pressure is applied to the joint for a short period of time, to wet the substrate adequately in order to attain a certain, albeit minimal, level of joint strength. Thus, the term pressure-sensitive is often applied to this class of adhesives. 

Paraflow is an important pour point dcpre.ssant which, when present in concentrations of 1 to 2 per cent, may reduce the Wax pour point of an oil by 50°F or more. Paraflow is a poly-alkyl naphthalene and is prepared by condensing chlorinated wax with naphthalene in the presence of anhydrous aluminium chloride which acts as a catalyst... 

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