Ammonolysis and Aminolysis

These treatments have been less widely investigated for PET chemical recycling. Ammonolysis consists of the reaction of PET with ammonia at temperatures between 70 and 180°C, usually under pressure and in the presence of ethylene glycol.65 The main product of the degradation is the TPA amide, which is obtained with a purity above 99% and in yields of around 90%. This reaction is also catalysed by zinc acetate, as in other PET chemolysis processes mentioned above. 

PET depolymerization by aminolysis is based on the reaction with primary amines such as methylamine, ethylamine and ethanolamine.66 69 The degradation takes place at temperatures in the range 20-100 °C and the studies carried out show that the attack of the amine is located preferentially on the amorphous regions of the polymer, because it is difficult to achieve a total PET conversion. 

The final products of PET aminolysis are the amides of TPA and ethylene glycol. 

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Ammonolysis and Aminolysis. Esters and ammonia react to form amides and alcohols ... 

Polyurethanes (PUs, PURs), 197-258 ammonolysis and aminolysis of, 556 analytical techniques for, 241-246 applications, properties, and processing methods for, 198, 202-205 application testing of, 244-245 blood contact applications for, 207 chemical structure of, 5 chemistry and catalysis of, 222-236, 546... 

The strategy described here explains the different possibilities of enzymatic ammonolysis and aminolysis reaction for resolution of esters or preparation of enantiomerically pure amides, which are important synthons in organic chemistry. This methodology has been also applied for the synthesis of pyrrolidinol derivatives that can be prepared via enzymatic ammonolysis of a polyfunctional ester, such as ethyl ( )-4-chloro-3-hydroxybutanoate [30]. In addition, it is possible in the resolution of chiral axe instead of a stereogenic carbon atom. An interesting enzymatic aminolysis of this class of reaction has been recently reported by Aoyagi et al. [31[. The side chain of binaphthyl moiety plays an important role in the enantiodis-crimination of the process (Scheme 7.14). 

An interesting series of ammonolysis and aminolysis products has been obtained from the cyclophosphazene (36) (see Scheme 2). It is note-... 

Yet another similar route to biguanides utilises the ammonolysis and aminolysis of 0-alkylamidino soureas. The use of this group of reactions, first briefly referred to in the patent literature 516), was developed by Curd and his co-workers who fcst published 138, 139) adequate experimental details it was later patented in Japan 353, 354). 

Theoretical studies of the ester enolate-imine reaction <98MI1826>, the effects of solvation on barriers of reaction <99JPC8628>, interactions of P-lactams in aqueous solution <99MI1401> and their ammonolysis and aminolysis <99JOC3281,99MI1045> are available. 

Other less well-established PET chemolysis methods include degradation by ammonolysis and aminolysis. Degradation of PET by combined treatments has evolved in recent years as an interesting alternative, benefiting from the advantages of each individual process. Thus, a number of combined processes have recently been developed glycolysis-hydrolysis, methanolysis-hydrolysis and glycolysis-methanolysis. 

Ammonolysis and aminolysis phosphonothioic amides and related compounds... 

Ammonolysis and aminolysis in the gas phase are generally exothermic in nature except in the case of hydrocarbons. 

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