Adipic acid, from decomposition

Carothers next step was to move from polyesters to nylons and to increase the fractional conversion (p) by making salts using the equivalent reaction of 1,6-hexanediamine (hexamethylenediamine) and adipic acid. These salts were recrystallizable from ethanol giving essentially a true 1 1 ratio of reactants. Thus, a high molecular weight polyamide, generally known as simply a nylon, in this case nylon-6,6, was produced from the thermal decomposition of this equimolar salt as shown in structure 4.55. This product has a melting point of 265°C. 

Post and co-workers [49] have used TG-FTIR to study the outgassing of a plasticiser (type and amount) from an ethylene-propylene-diene terpolymer (EPDM) compound. Figure 1.6 shows the thermogravimetric decomposition behaviour of the EPDM compound. The plasticiser emerges in the first mass-loss step, which was identified as adipic acid diisobutylester by on-line infrared analysis. 

The literature of this reaction to 1940 has been adequately reviewed. The emphasis up to that time was placed on obtaining higher yields of carbonyl compounds by hydrolysis of the ozonides. Several methods have been described for the oxidative cleavage of ozonides to acids. These procedures may prove valuable in the synthesis of certain acids. By adding the ozonide of 1-tridecene to an alkaline silver oxide suspension at 95°, a 94% yield of lauric acid is obtained. Decomposition of ozonides with 30% hydrogen peroxide is described for the preparation of 5-methyl-hexanoic acid (67%) from 6-methyl-l-heptene and of adipic acid (60%) from cyclohexene. A study of solvents for ozonolysis has been made. ... 

Because of the large scale of adipic acid manufacture, emissions of N2O from this source are significant. Since the 1990s, measures have been put in place to prevent N2O reaching the atmosphere. Both thermal destruction and catalytic (e.g. CUO/AI2O3) decomposition convert N2O to N2 and O2. 

For materials based on MDI and polyester SS, the initial decomposition point is 227°C [244]. Much higher decomposition temperature, i.e. 319°C was recorded for polyester PUs achieved with TDI and polyesters derived from adipic acid, ethyl glycol and neopentyl glycol, and trimethylolpropane [245]. Decomposition of the urethane bonds in polyester PUs based on the diisocyanate MDI and chain extended with EG begins at 240°C, and it reaches its maximum rate at 337-356°C [246]. Decomposition of PUs obtained form TDI was observed to start as early as at 200 C and to run through three steps with polybutadiene derived PUs being more stable [247]. 

Nitrous oxide is obtained in commercial quantities by the thermal decomposition of ammonium nitrate and by recovery from a by-product stream from adipic acid manufacturing processes. 

Besides, successful attempts based on the oxidation of cyclohexanone/ cyclohexanol mixture by HNO3 were obtained for controlling N2O as primary side product from adipic acid plant (Eqs. (27.1) and (27.2)). Indeed, the abatement of huge amount of N2O from the exothermic decomposition of N2O (AH — -81.5 kj/mol) can be valorized through the production of steam that can be reused for others chemical processes [6]. In this specific case, two different technologies have been envisioned thermal destruction and catalytic decomposition. 

The context differs from the previously described adiabatic decomposition of high concentration of NgO from adipic acid plants. As a matter of fact, a wide variety of catalysts can be active in such operating conditions and do not... 

The predominant gaseous products of the decomposition [1108] of copper maleate at 443—613 K and copper fumarate at 443—653 K were C02 and ethylene. The very rapid temperature rise resulting from laser heating [1108] is thought to result in simultaneous decarboxylation to form acetylene via the intermediate —CH=CH—. Preliminary isothermal measurements [487] for both these solid reactants (and including also copper malonate) found the occurrence of an initial acceleratory process, ascribed to a nucleation and growth reaction. Thereafter, there was a discontinuous diminution in rate (a 0.4), ascribed to the deposition of carbon at the active surfaces of growing copper nuclei. Bassi and Kalsi [1282] report that the isothermal decomposition of copper(II) adipate at 483—503 K obeyed the Prout—Tompkins equation [eqn. (9)] with E = 191 kJ mole-1. Studies of the isothermal decompositions of the copper(II) salts of benzoic, salicylic and malonic acids are also cited in this article. 

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