Peroxide decomposition, cellulose

When cellulose is exposed to the unlimited supply of oxygen present as 21% of the air, unstable peroxide radicals form. In the autocatalytic reaction of cellulose oxidation, decomposition of peroxide forms cellulose radicals that react with oxygen to form R02- radicals. These radicals attack other cellulose molecules to form oxycelluloses (carbonyl, aldehyde, and carboxyl acid groups) along with more cellulose free radicals (34). 

Yildiz H, Akyilmaz E, Din9kaya E (2004) Catalase immobilization in cellulose acetate beads and determination of its hydrogen peroxide decomposition level by using a catalase biosensor. J Artif Cells Blood Subst Biotechnol 32(3) 443 52 Yu M, de Swaan Arons J, Smit JA (1994). A simple model for estimating protein solubility in aqueous polymer solutions. J Chem Technol Biotechnol 60(4) 413 18... 

The decomposition of benzoyl peroxide on cellulose has been studied. ... 

MMA onto cellulose was carried out by Hecker de Carvalho and Alfred using ammonium and potassium persulfates as radical initiators [30]. Radical initiators such as H2O2, BPO dicumylperoxide, TBHP, etc. have also been used successfully for grafting vinyl monomers onto hydrocarbon backbones, such as polypropylene and polyethylene. The general mechanism seems to be that when the polymer is exposed to vinyl monomers in the presence of peroxide under conditions that permit decomposition of the peroxide to free radicals, the monomer becomes attached to the backbone of the polymer and pendant chains of vinyl monomers are grown on the active sites. The basic mechanism involves abstraction of a hydrogen from the polymer to form a free radical to which monomer adds ... 

Figure 10.27 Effect of sequestering agent concentration on the decomposition of hydrogen peroxide and degree of polymerisation of cotton cellulose [236]...

The base readily penetrates the hair and promotes bleaching. The addition of stabilizers such as sodium pyrophosphate or sodium oxalate [16,17] retards the decomposition of hydrogen peroxide in the alkaline preparation and thus enhances the bleaching action. The same holds for complexing agents (seques-trants) such as ethylenediaminetetraacetic acid, which hinder decomposition due to traces of heavy metals. Thickening additives include carboxymethyl celluloses, xanthine derivatives, and synthetic polymers. Certain dyes can also be added. 

Especially important are the radical-redox reactions by which transition metals promote free radical generation by catalyzing the decomposition of the peroxides formed during bleaching. This faster free radical generation results in higher oxidation rates and a more extensive depolymerization of the cellulose. 

Transition metal species can accelerate this chain of events by catalyzing the homolytic decomposition of cellulosic peroxide molecules (5) ... 

The influence of the concentration of iron ions on decomposition of hydrogen peroxide in bleaching liquor is shown in Fig. 12-11. The influence of the concentration of complexing agent on decomposition of iron complexing peroxide bleaching liquor and cellulose is shown in Fig. 12-12. The rapid release of large amount... 

Hydrogen peroxide is virtually the only bleaching agent available for protein fibres and it is also used very extensively for the cellulosic fibres. It was at one time thought that its oxidizing action depended upon the fact that it readily underwent decomposition with the liberation of oxygen ... 

In the presence of methoxy magnesium methyl carbonate, the chemiluminescence emission in pullulan and cellulose increased significantly. It may be attributed to the decomposition of dioxetanes, with higher quantum yield of emission, which were formed from peroxidation of terminal semiacetal groups in the presence of MgO. 

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