On the Mechanism of the Ionizing Radiation-Induced Degradation and Recycling of Cellulose

Richard List; Lorelis Gonzalez-Lopez; Aiysha Ashfaq; Amira Zaouak; Mark Driscoll; Mohamad Al-Sheikhly

doi:10.3390/polym15234483

On the Mechanism of the Ionizing Radiation-Induced Degradation and Recycling of Cellulose

Polymers (Basel). 2023 Nov 22;15(23):4483. doi: 10.3390/polym15234483.

Authors

Richard List^{1

2}, Lorelis Gonzalez-Lopez³, Aiysha Ashfaq⁴, Amira Zaouak⁵, Mark Driscoll^{2

6}, Mohamad Al-Sheikhly³

Affiliations

¹ Department of Chemical Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
² UV/EB Technology Center, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
³ Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA.
⁴ Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
⁵ Research Laboratory on Energy and Matter for Nuclear Science Development, National Center for Nuclear Science and Technology, Sidi-Thabet 2020, Tunisia.
⁶ Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA.

Abstract

The use of ionizing radiation offers a boundless range of applications for polymer scientists, from inducing crosslinking and/or degradation to grafting a wide variety of monomers onto polymeric chains. This review in particular aims to introduce the field of ionizing radiation as it relates to the degradation and recycling of cellulose and its derivatives. The review discusses the main mechanisms of the radiolytic sessions of the cellulose molecules in the presence and absence of water. During the radiolysis of cellulose, in the absence of water, the primary and secondary electrons from the electron beam, and the photoelectric, Compton effect electrons from gamma radiolysis attack the glycosidic bonds (C-O-C) on the backbone of the cellulose chains. This radiation-induced session results in the formation of alkoxyl radicals and C-centered radicals. In the presence of water, the radiolytically produced hydroxyl radicals (^●OH) will abstract hydrogen atoms, leading to the formation of C-centered radicals, which undergo various reactions leading to the backbone session of the cellulose. Based on the structures of the radiolytically produced free radicals in presence and absence of water, covalent grafting of vinyl monomers on the cellulose backbone is inconceivable.

Keywords: cellulose ionizing-radiation; degradation; recycling; structure.

Publication types

Review

Grants and funding

This research received no external funding.