TEMPO-oxidized cellulose nanofibers: A potential bio-based superabsorbent for diaper production

Abstract

Single-use plastics are expected to disappear, mainly due to the rise of stricter regulations to combat their impact on the environment. As an example, the recent European Directive on Single-Use-Plastics (SUP) will be implemented between 2021 and 2024 and will directly prohibit the use of some SUP. Baby diapers are one of the most used single-used products in our daily lives, and it is estimated that most of the ~4000 diapers that each baby uses in their life go to landfill. Such diapers usually contain superabsorbent polymers (SAP) that are based on acrylic acid-acrylamide mixtures with high water retention capacity, but they are neither bio-based nor biodegradable. In this work, we have developed bio-based superabsorbent aerogels made of cellulose nanofibers (CNF) and propose their potential use in baby diapers. TEMPO-oxidized CNF at different oxidation degrees were prepared and tested. The obtained CNF exhibited higher free swelling capacity (FSC) than the commercial fluff pulp (ranging from 117.62% to 245.21% higher) and also than the diaper absorbent, except for CNF-5 (ranging from 31.56% to 54.55%), even under compression. Overall, the present work shows a case study where CNF could have a potential application with market opportunities.