Crosslinking and degradation of polymers

Improvement of antioxidant activity of chitosan by chemical treatment and ionizing radiation

“…Radiation can provide a useful tool for degradation of different polymers. In the reaction, no other chemical reagents are introduced and there is not a need to control the temperature, environment or additives [17]. Beside the reduction in chitosan molecular weight, the development of chitosan for antioxidant activity has to overcome: (i) poor solubility; (ii) chemical inertness based on the strong inter-and intra-molecular hydrogen bonds network and (iii) poor H-atom donating ability to serve as a good chain-breaking antioxidant.…”

Structural feature and antioxidant activity of low molecular weight laminarin degraded by gamma irradiation

“…Recently, it has been reported that gamma irradiation leads to the degradation of polysaccharides by the cleavage of glycosidic bonds Charlesby, 1981;Kim et al, 2008;Nagasawa, Mitomo, Yoshii, & Kume, 2000). The basic advantages of the degradation of polymers by irradiation include a simple process (simultaneously with sterilisation), no introduction of chemical reagents, minimised structural changes and side reactions, random scission kinetics, and no further purification steps.…”

Enhancement of enzymatic hydrolysis of wheat straw by gamma irradiation–alkaline pretreatment

“…In previous study, it was found that the chain scission reaction was predominant over cross-linking at first, and then the latter was predominant for the irradiated wheat straw with the extension of storage time after radiation process (Yang et al, 2008). The efficiency of radiation-induced chain scission and cross-linking reactions depended mainly on the polymer structure and dose (Charlesby, 1981). Although the direct determination of cross-linking in irradiated cellulose is impossible, it is believed that the cross-linking reaction should be occurred in irradiated cellulose (Kovalev and Bugaenko, 2003).…”