Electron Beam Irradiation of Cellulosic Materials—Opportunities and Limitations

Abstract

Abstract:The irradiation of pulp is of interest from different perspectives. Mainly it is required when a modification of cellulose is needed. Irradiation could bring many advantages, such as chemical savings and, therefore, cost savings and a reduction in environmental pollutants. In this account, pulp and dissociated celluloses were analyzed before and after irradiation by electron beaming. The focus of the analysis was the oxidation of hydroxyl groups to carbonyl and carboxyl groups in pulp and the degradation of cellulose causing a decrease in molar mass. For that purpose, the samples were labeled with a selective fluorescence marker and analyzed by gel permeation chromatography (GPC) coupled with multi-angle laser light scattering (MALLS), refractive index (RI), and fluorescence detectors. Degradation of the analyzed substrates was the predominant result of the irradiation; however, in the microcrystalline samples, oxidized cellulose functionalities were introduced along the cellulose chain, making this substrate suitable for further chemical modification.

Cellulose nanofibrils in biobased multilayer films for food packaging

“…The CO/cellulose band area ratio was somewhat higher in the irradiated (5 kGy) film compared to the nonirradiated film (0.128 ± 0.002 vs. 0.118 ± 0.001, respectively). This result is in accordance with earlier observations related to oxidation of cellulose and explains the impaired oxygen barrier property of the films with the CNF layer . The IR spectra of the CNF films [Figure (a)] are normalized at the cellulose band 1057 cm −1 to the value 1.0 log (1/ R ), and the IR spectra of the PE film [Figure (b)] are normalized at the CH band 2918 cm −1 to the value 1.0 log (1/ R ).…”

“…In addition, a decrease in water content has been observed. Similar changes have been observed with cellulose . In addition, oxidative degradation of cellulose can take place .…”

Changes in mechanical and chemical wood properties by electron beam irradiation

“…Previous chemical analysis revealed the effect of radiation on wood and cellulosic materials in increases in carbonyl groups, depolymerisation of cellulose and decreases in aliphatic hydroxyls groups and guajacyl residues [8][9][10]23]. Table 1 presents selected absorption band assignments according to Faix [24] and Schwanninger et al [25].…”

Irradiation Pretreatment of Tropical Biomass and Biofiber for Biofuel Production

“…Also, reduction of the biomass mechanical strength has been observed from the biomass exposed to electron beam. This could be due to the disruption of hydrogen bond between cellulose chains making it less crystalline and more amorphous [40]. Recently various research groups have studied the potential of electron beam radiation on various type of biomass including tropical biomass and biofiber such as bamboo, rice straw, oil palm, fruit bunch, and kenaf [30,41,42].…”

“…Even though this irradiation pretreatment procedure is quite simple, it is undeniable that the high-energy consumption associated with it makes the process not preferable for implementation on a commercial scale [40,96]. Besides, this process requires a special reactor that could affect during large-scale process.…”