Degradation stages

JS) and of products of two successive periodate oxidation and Smith degradation stages (38). 

Alkaline hydrolysis of benzal acetone structures to the corresponding aldehyde (XIX) and acetone and subsequent oxidation of the aldehyde (XIX) to the corresponding benzoic acid (V) do not seem to represent an actual degradation stage since oxidizing the aldehyde (XIX) under our mild standard conditions yielded only traces of the corresponding benzoic acid (V). The aldehyde (XIX) was rapidly decomposed via Dakin reaction to formic acid and 3-methoxy-S-methyl-o-benzoquinone, which is immediately degraded to phenolic humic compounds. 

Gonzalez-Vila,F. J.,Tinoco, P., Almendros, G., and Martin,F. (2001). Pyrolysis-GC-MS analysis of the formation and degradation stages of charred residues from lignocellulosic biomass. I. Agric. Food Chem. 49,1128-1131. 

According to recent results [105,124-126] it seems that three separate degradation stages have been pointed out. The first one, which is the lower temperature process, is the main source of weight loss it could correspond to the rapid alteration of norbornenyl moeities [42,105,124-127]. Formation of CPD was evidenced [126] and it is more probably formed from polycycloadduct imides than from unreacted nadimides [42]. 

Silica nanoparticles are a promising component of FR systems because of their effect on viscosity in the molten state and the potential ability to react with many other chemical compounds, particularly during degradation stages of filled polymers. 

The slow degradation stage was characterized by relatively few DP changes, especially after reaching the so-called leveling-off DP (LODP)... 

Deposition of asphaltenes from crude oil A series of degradation stages as crude oil is heated has been described by Eaton and Lux [1984]. The process is similar to (1), i.e. oxidation and polymerisation. 

Figure 32. Pressure drop across the jets vs. e for a 0.35% a-PS-decahydro-naphthalene solution (M - 7.7 x JO ). The solid line corresponds to the fresh solution and the other two lines show degradation stages (see Table II).

Table 7.7 Temperature range, DTGA peak temperature, statistical parameters, and activation energies of the degradation stages of CMC and its complexes with some transition metals...

Complexation of cellulose ether with some transition metals does not behave in the same manner as that observed for parent cellulose ether (i.e., the number of degradation stages was increased and order of degradation were varied). This is due to the elimination of coordinated water and decomposition of cellulose ether-metal coordination bonds. 

Table 7.21 Thermal degradation measurements of copper complex-containing paper sheets in comparison to wood pulp sheet (main degradation stage)...

Note-. is the activation energy of the main degradation stages. 

Results also indicate that a second, possibly overlapping, degradation stage will be scission of the Ph(C=0)-0Ph bond in the mesogenic section of the chain. This may then lead to the appearance of aldehydic and further phenolic species via hydrogen abstraction. 

The standard ASTM D6954-04 is used for the exposure of plastics that can degrade by a combination of oxidation and biodegradation (87). This standard should permit the comparison and ranking of the overall rate of the environmental degradation of plastics in the course of thermal or photo oxidation. Each degradation stage is independently evaluated to allow a combined evaluation of a polymer s environmental performance. 

Some of the common key microorganisms involved in the different degradation stages of the anaerobic digestion process can be seen in Table 19.1. In the absence of microbial inhibitory conditions, the distribution and balance of the various microorganisms in any anaerobic digestion system depend on the nature of the available substrates. 

Kearsey HA, Chidley BE, Hornby J, Carbon fibre precursor materials Reaction kinetics of some acrylics in the oxidative degradation stage, AERE report R6222, 1969. 

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