Cellulose nitrate salt effect

Mino and Kaizerman [12] established that certain. ceric salts such as the nitrate and sulphate form very effective redox systems in the presence of organic reducing agents such as alcohols, thiols, glycols, aldehyde, and amines. Duke and coworkers [14,15] suggested the formation of an intermediate complex between the substrate and ceric ion, which subsequently is disproportionate to a free radical species. Evidence of complex formation between Ce(IV) and cellulose has been studied by several investigators [16-19]. Using alcohol the reaction can be written as follows ... 

Certain researchers have preferred soluble salts such as iron(III) nitrate [236] to represent deliberate contamination, whilst others have used insoluble forms. However, even iron (III) oxide in the form of rust is found to vary in catalytic activity depending on physical form. Although uniform distribution of the contamination, at least below a relatively low concentration, has been claimed to be less troublesome than localised concentrations, there is not even agreement on this. A further complication is that different studies have been carried out in either the absence or the presence of a cellulosic substrate. With these provisos in mind, the catalytic behaviour of trace metals and the effects of some preventive agents will be outlined. 

When the source of initiation is altered from ionising radiation to UV, analogous additive effects to those previously discussed have been found. For reasonable rates of reaction, sensitisers such as benzoin ethyl ether (B) are required in these UV processes. Thus inclusion of mineral acid or lithium perchlorate in the monomer solution leads to enhancement in the photografting of styrene in methanol to polyethylene or cellulose (Table V). Lithium nitrate is almost as effective as lithium perchlorate as salt additive in these reactions (Table VI), hence the salt additive effect is independent of the anion in this instance. When TMPTA is included with mineral acid in the monomer solution, synergistic effects with the photografting of styrene in methanol to polyethylene are observed (Table VII) consistent with the analogous ionising radiation system. 

The effect of nitrating cellulose with 100% nitric acid in the presence of different salts [51]... 

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