Sucrose, thermal decomposition

The pores of the silica template can be filled by carbon from a gas or a liquid phase. One may consider an insertion of pyrolytic carbon from the thermal decomposition of propylene or by an aqueous solution of sucrose, which after elimination of water requires a carbonization step at 900°C. The carbon infiltration is followed by the dissolution of silica by HF. The main attribute of template carbons is their well sized pores defined by the wall thickness of the silica matrix. Application of such highly ordered materials allows an exact screening of pores adapted for efficient charging of the electrical double layer. The electrochemical performance of capacitor electrodes prepared from the various template carbons have been determined and are tentatively correlated with their structural and microtextural characteristics. 

Kinetic studies of the thermal decomposition of sucrose in weakly basic medium have shown that the process is comprised of two independent reactions, namely, the decomposition of D-glucose and D-fhictose. Such decomposition is described by a first-order equation. The decomposition of D-glucose under the conditions applied is slower than that of D-fructose and, therefore, the first process is the rate-limiting step. The rate of the thermal decomposition is temperature- (T) and pH-dependent, according to the... 

Kelly, F.H.C. Brown D.W. Thermal decomposition and colour formation in aqueous sucrose solutions. Sugar Technol Rev. 1978/79, 6, 1-48. 

The products of caramelization are distributed between volatile and nonvolatile fractions. The composition of the volatile firaction is pretty well characterized, contrary to that of the nonvolatile fraction. Thus, neither is the structure of all compounds formed precisely known, nor are the processes which occur understood in detail (see, for instance, a review by Orsi ). The composition of the volatile fraction from the thermolysis of sucrose is the best recognized. The profound decomposition products from the decomposition in vacuo of sucrose arc water, carbon monoxide, carbon dioxide, formaldehyde, acetaldehyde, methanol, and ethanol. The detailed rates and temperature relationships suggest that, with the possible exception of ethanol, the other products result from secondary reactions of dehydration products. The low-molecular-weight portion of the nonvolatile fraction of the thermal degradation of sucrose contains D-fhictose, D-glucose,... 

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