The hydrolysis of ethyl glycinate in sulphuric acid solutions

1967 ◽  
Vol 20 (8) ◽  
pp. 1757
Author(s):  
RW Hay ◽  
L Main
2017 ◽  
Vol 371 ◽  
pp. 59-72
Author(s):  
Soon Yee Liew ◽  
Wim Thielemans ◽  
Buddhika Hewakandamby

In this paper, the phase behaviour of a cellulose nanocrystal (CNCs) dispersion in sulphuric acid solutions was investigated, aimed at the development of an energy efficient separation method for this mixture. The system in consideration was a mixture of 30 wt% aqueous sulphuric acid (ρl = 1219 kg/m3) containing 12.6 mg/ml of cellulose nanocrystals (CNCs) (ρs = 1590 kg/m3, volume fraction of CNCs less than 1%). This volume filling mixture was obtained directly from a CNC extraction process, as obtained after the hydrolysis of cotton using 64 wt% sulphuric acid at ca. 45 ̊C for 45 minutes (this condition was required for the extraction of CNCs from cotton) followed by quenching the hydrolysis with water. The CNCs form the desired product and need to be separated from the acid that can then be recycled. Conventionally this separation has been difficult and requires a large input of energy. This work addresses this problem by investigating into the phase behaviour and physicochemical and hydrodynamic character of this mixture. This understanding led to the development of a very energy efficient separation mechanism for this mixture, which is 5 orders of magnitude more energy efficient than the most widely used centrifugation systems.


1942 ◽  
Vol 20b (8) ◽  
pp. 168-173 ◽  
Author(s):  
J. D. McLean ◽  
B. S. Rabinovitch ◽  
C. A. Winkler

The study of the hydrolysis of propionitrile in concentrated acid solutions has been extended to hydrobromic, nitric, and sulphuric acids for a range of acid concentrations. For the system of irreversible, unimolecular consecutive reactions, nitrile [Formula: see text] amide [Formula: see text] acid, [Formula: see text] for all acid concentrations below 4 N. At higher concentrations, k1 and k2 are of the same order, and, in the case of sulphuric acid, k1 becomes [Formula: see text]k2 at concentrations above 20 N. The observed activation energy decreases with increasing acid concentration for all acids. The specific differences in rate increase with acid concentration may be accounted for by the specific variations of A and E for each acid.


1997 ◽  
Vol 432 (1-2) ◽  
pp. 1-5 ◽  
Author(s):  
Roberto Gómez ◽  
JoséM. Orts ◽  
Juan M. Feliu ◽  
Jean Clavilier ◽  
Lorena H. Klein

1975 ◽  
Vol 28 (3) ◽  
pp. 673 ◽  
Author(s):  
DJ Collins ◽  
C Lewis ◽  
JM Swan

Treatment of cyclododecane-r-1,c-5,c-9-triyl tris(p-toluenesulphonate) with sodium azide in dimethyl-formamide at 100� for 6 h gave the corresponding cis,cis-triazide which upon hydrogenation or reduction with lithium aluminium hydride gave cyclododecane-r-1,c-5,c-9-triamine, isolated as the tris-salicylidene derivative. Acid hydrolysis of this, removal of the salicylaldehyde, and treatment of the aqueous solution with sodium carbonate and 2,3-dimethoxybenzoyl chloride gave r-1,c-5,c- 9-tris(2,3-dimethoxybenzamido)cyclododecane. ��� Treatment of (E,E,E)-cyclododeca-1,5,9-triene with an excess of acetonitrile and sulphuric acid at room temperature for three days gave 18% of (E,E)-1-acetamidocyclododeca-4,8-diene; no di- or tri-amides were isolated.


1963 ◽  
Vol 41 (10) ◽  
pp. 2439-2446 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau
Keyword(s):  

After repeated and vigorous treatments, a fully methylated glucan was obtained. Hydrolysis of the methylated glucan with sulphuric acid gave tetra-, tri-, di-, and mono-O-methyl-D-glucoses in a 5:5:3:1 ratio. Both the furanose and pyranose tetramethyl isomers were identified. Nearly all of the possible pyranose and furanose cyclic trimethylglucoses were positively identified. An attempted resolution of the dimethylglucoses was relatively unsuccessful. The monomethylglucoses were identified by electrophoresis.


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