Interpenetrating and semi-interpenetrating network superabsorbent hydrogels based on sodium alginate and cellulose nanocrystals: A biodegradable and high-performance solution for adult incontinence pads

Saeed Ismaeilimoghadam; Mehdi Jonoobi; Alireza Ashori; Afsaneh Shahraki; Bahareh Azimi; Serena Danti

doi:10.1016/j.ijbiomac.2023.127118

Interpenetrating and semi-interpenetrating network superabsorbent hydrogels based on sodium alginate and cellulose nanocrystals: A biodegradable and high-performance solution for adult incontinence pads

Int J Biol Macromol. 2023 Dec 31;253(Pt 8):127118. doi: 10.1016/j.ijbiomac.2023.127118. Epub 2023 Oct 4.

Authors

Saeed Ismaeilimoghadam¹, Mehdi Jonoobi², Alireza Ashori³, Afsaneh Shahraki⁴, Bahareh Azimi⁵, Serena Danti⁶

Affiliations

¹ Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Karaj, Iran.
² Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Karaj, Iran. Electronic address: mehdi.jonoobi@ut.ac.ir.
³ Department of Chemical Technologies, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran. Electronic address: ashori@irost.ir.
⁴ Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Zabol, Zabol, Iran.
⁵ Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy.
⁶ Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy. Electronic address: serena.danti@unipi.it.

PMID: 37802434
DOI: 10.1016/j.ijbiomac.2023.127118

Abstract

Superabsorbent hydrogels (SAHs) are essential in various applications, including hygienic products like adult incontinence pads. However, synthetic-based super absorbent polymers (SAPs) dominate the market despite being non-biodegradable. Alternatively, bio-based hydrogels, such as sodium alginate (SA)-based hydrogels, offer biodegradable alternatives. In this study, we aimed to enhance the practical applied properties of SA-based hydrogels by grafting SA with acrylic acid (AA) and incorporating cellulose nanocrystals (CNCs). Specifically, we investigated the potential of interpenetrating network (IPN) and semi-interpenetrating network (S-IPN) hydrogels as absorbent materials in adult incontinence pads. The fabricated SAHs were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). They were also evaluated for absorption and rheological properties. The results showed that in IPN/SAHs, the addition of CNCs decreased pore sizes, while in S-IPN/SAHs, CNC incorporation increased pore sizes. The S-IPN/SAHs exhibited a significantly higher free swelling capacity (FSC) with CNCs loading, reaching 142.29 g/g in 0.9 % NaCl solution and 817.4 g/g in distilled water. On the other hand, IPN/SAHs showed a higher storage modulus and lower loss modulus compared to S-IPN/SAHs. Notably, the superior samples from this study showed a 33 % reduction in SAP consumption compared to commercial SAPs, making them more cost-effective for adult incontinence pad manufacturers. Overall, our research demonstrates the potential of interpenetrating and semi-interpenetrating network superabsorbent hydrogels as high-performance absorbent materials. The results offer improved absorbency and cost savings for producers of adult incontinence pads, and bio-based hydrogels like SA-based hydrogels are promising biodegradable alternatives to synthetic-based SAPs.

Keywords: Adult incontinence pads; Cellulose nanocrystal; Rheological properties; Super absorbent hydrogel.

MeSH terms

Alginates / chemistry
Cellulose* / chemistry
Hydrogels / chemistry
Incontinence Pads
Nanoparticles*
Polymers / chemistry
Spectroscopy, Fourier Transform Infrared

Substances

Cellulose
Alginates
Hydrogels
Polymers