Naphthalene condensation products

For a pitch from the pyrolysis of naphthalene, heptameric and octameric naphthalene condensation products have been postulated as model mesogens the corresponding molecular weights are 878/876 and 1006/1008 (Figure 13.4). 

Naphthalenesulfonic Acid—Formaldehyde Condensates. The sodium salts of the condensation products of naphthalenesulfonic acid with formaldehyde constitute an important class of compounds which are mainly used in the area of concrete additives (32,33), agricultural formulations, mbber formulations, and synthetic tanning agents. They are also used in photographic materials (34). Hampshire Chemical Co. and Henkel of America, Inc., are the largest suppHers of naphthalene sulfonate in concrete additives (superplasticizer) and reportedly hold 75—80% of this market. It was estimated that naphthalene sulfonate demand from U.S. producers would reach approximately... 

In more recent times, naphthalene has been used in condensation products from naphthalene sulfonic acids, utili2ing formaldehyde as additives to improve the flow properties of concrete these are referred to as superplastici2ers. Another newer appHcation is the production of diisopropylnaphthalenes. The mutual depression of the melting points in the mixture gives a Hquid which is used as a solvent for dyes in the production of carbonless copy paper. 

Naphthalene and other aromatic hydrophobes are also used to produce sulphonates, such as structure 9.17. Of greater importance, however, are the more complex condensation products that form the basis of many excellent dispersing, resist and aftertreating (syntan) agents. Typical examples are the condensation products of naphthalenesulphonates with formaldehyde, and the lignosulphonates derived from pulping processes these are described in more detail in section 10.6.1. 

The sulphonated aromatic condensation products form a large and varied group, since formaldehyde will condense with many aromatic compounds [330], including sulphonated arylamines, phenols and aliphatic ketones the range of commercially important products is relatively limited, however. One of the oldest is the condensation product of naphthalene-2-sulphonic acid and formaldehyde (10.99), in which the degree of condensation is thought to... 

In the present estimation, a continuous dehydrogenation reactor in which decalin is supplied to the catalyst at various feed rates without internal refluxing is assumed. Here all the condensable products and unconverted decalin were removed from the reactor to the condensation part (see Figure 13.22). Now, the stationary rates of hydrogen generation (VH), naphthalene formation (VN), and evaporation of unconverted decalin (VD) are defined as the magnitudes per area of the catalyst layer (mol/m2h). All these rates are expressed from mass balance as follows . 

The acid, referred to as tetra acid , is prepared as follows In a Friedel-Crafts reaction, acenaphthene 72 is reacted with malonic dinitrile and aluminum chloride. The resulting condensation product 75 is oxidized with sodium chlorate/hy-drochloric acid to form the dichloroacenaphthindandione 76. Oxidation with sodium hypochlorite solution/sodium permanganate affords naphthalene tetracar-boxylic acid 68, mostly existing as the monoanhydride 68a. The dianhydride, on the other hand, evolves only after drying at approx. 150°C. 

Salts of high-molecular-weight condensation product of naphthalene sulfonic acid. 

The dispersion agents used are primarily lignin sulfonates (sulfite cellulose liquors) condensation products of naphthalene, sulfuric acid, and formaldehyde condensation products of m - and o-cresol, formaldehyde, and 2-hydroxynaphtha-lene-6-sulfonic acid [93-01-6] or mixtures of these products [46], Literature on dispersing agents is relatively scarce [47-49],... 

It is noteworthy that biphenyl-type borazines result as byproducts from such reactions in up to 25% yield, while yields of decamethyl-N—B-diborazyl 38> from l,2,3,4,6-pentamethyl-5-lithioborazine 39-40> and l,2,3,4,5-pentamethyl-6-chloroborazine range between 40 and 50%. The formation of naphthalene-type borazine condensation products 5 has been claimed to occur in such reactions 41>42>. 

The reaction of benzyne with pyridine has been studied only at 690°C (benzyne generated from phthalic anhydride).96 The main condensable products in order of decreasing abundance were naphthalene, phenyl-pyridines (three isomers), bipyridyls, and quinoline. It is necessary to consider two modes of 1,4-cycloaddition, followed by rearomatization, to account for the formation of naphthalene (Eq. 4) and quinoline (Eq. 5), respectively. 

It is appropriate to emphasize here that many similar condensation reactions can be suggested. Thus, we easily prepared a condensation product of p-XDC with naphthalene, taken in stoichiometric ratio, which... 

Figure 13.4 Condensation products from the pyrolysis of naphthalene...

The monomer solution makeup involves addition and solubilization of elemental sulfur and rosin (substituted diterpenes) in the chloroprene monomer. The water solution is made in a second vessel. Deionized water, sodium hydroxide, and a dispersant are mixed to form the water solution. The dispersant is a condensation product of naphthalene-sulfonic acid and formaldehyde. The monomer and water solutions are mixed with centrifiigal pumps to form an oil-in-water emulsion. The emulsion formed by virtue of formation of the sodiiun salt of rosin and resin components (abietic and dehydroabietic acids) having hydrophobic and hydrophilic ends. The large carbon-bearing portion of sodium abietate is hydrophobic and thereby solubilizes the monomer. The sodium carboxylate portion of sodium abietate is the hydrophilic end that extends into the aqueous phase and forms the electronic double layer that is critical to emulsion stability (84,85). In the patent example, the emulsion was added to the reactor and the temperatiu-e was increased to 40°C polymerization temperatiu-e (Table 3). 

Commercial polymerizations are typically carried out in jacketed glass-lined kettles at about 40 C using potassium persulphate as initiator with the emulsifier being formed in situ using rosin, aqueous caustic soda and the sodium salt of a naphthalene sulphonic acid-formaldehyde condensation product. Monomer conversion is followed by measuring the specific gravity of the emulsion. In the case of sulphur-modified polychloroprenes polymerization may be... 

Anionic fixatives, e. g., the sodium salt of condensation products of formaldehyde and naphthalene sulfonic add, also form color lakes of this type with cationic dyes. They are used to improve the fixation of basic dyes on bleached pulps that contain only small amounts of hgnin. Better dye fixation always results in richer colors, improved bleed fastness, and less effluent staining. 

Naphthalene Sulfonic Aci(j - 180 82 - G — E formaldehyde, condensation product of CafOH). NaOH. CaS0 . Na>SO . natural aeration through agitation... 

Here again the naphthalene nucleus proved to be more reactive than the benzene ring. The condensation product from mesityl 2-naphthyl ketone and the methyl reagent, obtained in a yield of 74%, was 2-mesitoyl-1 -methyl-1,2-dihydronaphthalene (JO). 

Wax-naphthalene or w y -phenol condensation products and their polymers are said to be effective as pour-point reducers. Viscosity Index may be improved by the addition of butene polymers or polymers of methacrylic acid esters. Detergency additives are usually complex calcium or barium sulfonates or phenates. Such additives tend to keep carbonaceous sludgelike materials from settling out of the oil and will even clean such materials from a dirty engine. When a detergency additive is used, the crankcase oil almost immediately appears dark and dirty because the sludge is carried in suspension. When such an oil is... 

Chem. Descrip. Condensation product of formaldehyde and naphthalene sulfonate, Na salt Uses Dispersant for paints Properties Powd. 92% act. 

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