Phenolics water-base

Phenolic-neoprene contact cements are used for structural metal-metal bonding. especially where fatigue resistance and low temperature performance are important [209]. They are also used for bonding textiles, wood, rubbers, plastics, ceramics, and glass to metal and to one another. Solvent toxicity and flammability has greatly reduced the use of contact cements in the wood products industry. Water-based contact cements persist, but generally do not perform as well as the solvent systems, thus allowing market erosion by alternative binders. 

On boiling with water, diazoaminobenzenc decomposes into phenol and base,... 

V. N. Umutbaev, M. G. Kamaletdinov, B. A. Andreson, R. G. Abdrakhmanov, A. U. Sharipov, and I. V. Utyaganov. Lubricant additive for water-based drilling muds—contains a mixture of phenolic mannich bases, additional phosphoric acid and water. Patent SU 1799895-A, 1993. 

Towards water, alcohols, phenols, and bases the anhydrides behave, chemically, exactly as do the chlorides, except that the former react more slowly than the latter. 

The starting material is an 18 electron nickel zero complex which is protonated forming a divalent nickel hydride. This can react further with alkenes to give alkyl groups, but it also reacts as an acid with hard bases to regenerate the nickel zero complex. Similar oxidative addition reactions have been recorded for phenols, water, amines, carboxylic acids, mineral acids (HCN), etc. 

FIGURE 2.11 Influence of substitution on solute retention. Functional groups with phenol as base. Column Lichrosorb RP CIS 250 x4 mm mobile phase water. 

Non-sulfonated lignins find utility as emulsifiers and stabilizers in water-based asphalt emulsions, as coreactants in phenolic binder applications, as negative plate expanders in lead acid storage batteries, as protein coagulants in fat rendering, and as flocculants in waste water systems. 

A potentiometric method for determination of ionization constants for weak acids and bases in mixed solvents and for determination of solubility product constants in mixed solvents is described. The method utilizes glass electrodes, is rapid and convenient, and gives results in agreement with corresponding values from the literature. After describing the experimental details of the method, we present results of its application to three types of ionization equilibria. These results include a study of the thermodynamics of ionization of acetic acid, benzoic acid, phenol, water, and silver chloride in aqueous mixtures of acetone, tetrahydrofuran, and ethanol. The solvent compositions in these studies were varied from 0 to ca. 70 mass % nonaqueous component, and measurements were made at several temperatures between 10° and 40°C. 

In particular, they found enhanced bonding between metal surfaces and resins such as acrylics (solvent- and water-based), epoxy chlorinated rubbers, silicones, and polysulphides. It was noted that titanium complexes caused colouration with phenolics, whilst zirconium complexes did not. 

Derivatives of alkaline, alkaline earth metals and phenols, naphtols, an-troles, etc. (pK> 10). These compounds are salts in their nature and, as the salts of strong bases and moderately weak acids, can exist in water solutions. They are soluble only in polar solvents (water, liquid ammonia), are prone to form adducts with phenols, water, etc., have high thermal stability and cannot be transferred into the gas phase. 

It is reported that an industrial explosion was initiated by charging potassium hydroxide in place of potassium carbonate to the chloro-nitro compound in the sulfoxide [1], Dry potassium carbonate is a useful base for nucleophilic displacement of chlorine in such systems, reaction being controlled by addition of the nucleophile. The carbonate is not soluble in DMSO and possesses no significant nucleophilic activity itself. Hydroxides have, to create phenoxide salts as the first product. These are better nucleophiles than their progenitor, and also base-destabilised nitro compounds. Result heat and probable loss of control. As it nears its boiling point DMSO also becomes susceptible to exothermic breakdown, initially to methanethiol and formaldehyde. Methanethiolate is an even better nucleophile than a phenoxide and also a fairly proficient reducer of nitro-groups, while formaldehyde condenses with phenols under base catalysis in a reaction which has itself caused many an industrial runaway and explosion. There is thus a choice of routes to disaster. Industrial scale nucleophilic substitution on chloro-nitroaromatics has previously demonstrated considerable hazard in presence of water or hydroxide, even in solvents not themselves prone to exothermic decomposition [2],... 

Alawi [315] has described a simple and specific high performance liquid chromatographic method for the determination of nitrite and nitrate in non saline water based on the nitration of an excess of phenol by nitrate or oxidised nitrite ions the... 

Why then are these lignin sulfonates not used as a partial replacement for phenol in phenol-formaldehyde-based wood adhesives The first reason is that the presence of the sulfonate groups confers a water sensitivity to the adhesive. This sensitivity is exacerbated by the presence of water-soluble carbohydrates. A second reason is the low reactivity of the lignin sulfonates with formaldehyde and the consequent low level of crosslink density achieved in the final adhesive. A third reason is the molecular size of some of the lignin sulfonates. Large molecular weight material cannot penetrate the cell walls of the wood to form an adhesive continuum between contiguous wood particles. 

The most important industrial process for the production of 2-phenyl- and 2,6-diphenyl-phenol, is based on the long established self-condensations of cyclohexanone under either acidic, or preferentially basic conditions to give mono- or di-substituted aldol-like condensation products79). These easily loose water giving semicyclic or endocyclic ring double bonds. Plesec et al. have studied these reactions extensively 80). 

Among the limited examples of polymers originated by path b (Fig. 153), the polymerization- of diallylamino Mannich bases leading to poly(pyrrolidine)s 397 (Fig. 155) is worth mentioning. The synthesis of ionene polymers of the type 398, used in water clarification, by reaaion between /ran.v-l,4-dichloro-2-butene and a phenolic Mannich base,- is also interesting. 

Surface water photooxidation t,/j = 66-3480 h in water, based on reaction rate constants for OH and ROj radicals with the phenol class (Gtiesten et al. 1981 Mill Mabey 1985 quoted, Howard et al. 1991) rate constant k = (1.2 0.3) x 10 M- s- for the reaction with ozone at pH 1.5/2.0 (Hoign6 Bader 1983) Vj(aerobic) = 2 d, t,//anaerobic) = 15 d in natural waters (Capel Larson 1995)... 

Oxidation rate constant k, for gas-phase second order rate constants, Icqjj for reaction with OH radical, k os with NO3 radical and ko3 with O3 or as indicated, data at other temperatures see reference k < 4 X 10 M h for singlet oxygen, 1.1 x 10 M fh for peroxy radical at 25°C (Mabey et al. 1982) photooxidation = 77-3840 h in water, based on reported reaction rate constants for ROj radicals with the phenol class (Mill Mabey 1985 selected, Howard et al. 1991) photooxidation ty, = 8.0 h in air, based on reaction with photochemically produced hydroxyl radical in air (GEMS 1986 selected, Howard 1989) koH = 71.5 X 10 cm molecule- s- at 296 2 K (Atkinson 1989)... 

Surface water photooxidation t,/, = 77-3840 h in water, based on reported reaction rate constants for ROj radical with the phenol class (Mill Mabey 1985 quoted, Howard et al. 1991). 

---