Hydrolysis of cyanazine and related diaminochloro-1,3,5- triazines. Part II: hydrolysis in sulphuric acid solutions

1980 ◽  
Vol 11 (5) ◽  
pp. 493-505 ◽  
Author(s):  
B. Terence Grayson
Keyword(s):  
Sulphuric Acid ◽  
Acid Solutions ◽  
Hydrolysis Of

scholarly journals Phase Behaviour of Cellulose Nanocrystal Dispersion in Aqueous Sulphuric Acid and Development of an Energy Efficient Separation Technique for the Acid-Cellulose Nanocrystal System

2017 ◽  
Vol 371 ◽  
pp. 59-72
Author(s):  
Soon Yee Liew ◽  
Wim Thielemans ◽  
Buddhika Hewakandamby
Keyword(s):  
Sulphuric Acid ◽  
Energy Efficient ◽  
Volume Fraction ◽  
Extraction Process ◽  
Phase Behaviour ◽  
Cellulose Nanocrystal ◽  
Separation Mechanism ◽  
Acid Solutions ◽  
Efficient Separation ◽  
Hydrolysis Of

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.

THE HYDROLYSIS OF PROPIONITRILE IN CONCENTRATED SOLUTIONS OF MINERAL ACIDS

1942 ◽  
Vol 20b (8) ◽  
pp. 168-173 ◽  
Author(s):  
J. D. McLean ◽  
B. S. Rabinovitch ◽  
C. A. Winkler
Keyword(s):  
Activation Energy ◽  
Sulphuric Acid ◽  
Acid Concentration ◽  
Rate Increase ◽  
Acid Solutions ◽  
Concentrated Solutions ◽  
Consecutive Reactions ◽  
Mineral Acids ◽  
Hydrolysis Of

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.

The role of surface crystalline heterogeneities in the electrooxidation of carbon monoxide adsorbed on Rh(111) electrodes in sulphuric acid solutions

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

The synthesis of Cyclododecane-r-1,c-5,c-9-triamine and r-1,c-5,c-9-Tris(2,3-dimethoxybenzamido)cyclododecane

1975 ◽  
Vol 28 (3) ◽  
pp. 673 ◽  
Author(s):  
DJ Collins ◽  
C Lewis ◽  
JM Swan
Keyword(s):  
Aqueous Solution ◽  
Acid Hydrolysis ◽  
Sulphuric Acid ◽  
Sodium Carbonate ◽  
Sodium Azide ◽  
Room Temperature ◽  
Dimethyl Formamide ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium ◽  
Hydrolysis Of

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.

THE CONSTITUTION OF A SYNTHETIC GLUCAN: II. METHYLATION STUDIES

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

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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