Wet Strength Improvement of TEMPO-Oxidized Cellulose Sheets Prepared with Cationic Polymers

Abstract

Cellulose fibers were oxidized with a catalytic amount of 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) in water, and these TEMPO-oxidized cellulose fibers were subjected to sheet making with cationic polymers such as cationic poly(acrylamide) (C-PAM) and poly(vinylamine) (PVAm). The wet strength of the sheets thus prepared was evaluated in terms of the cationic polymer used. It was found that wet tensile strength of the sheets was clearly improved by the cationic polymer addition to the cellulose slurries. Especially, the C-PAM addition was effective in wet strength improvement of the sheets, when the TEMPO-oxidized cellulose fibers were used. The results obtained using the TEMPO-oxidized and then NaBH4-reduced cellulose fibers showed that aldehyde groups present in the TEMPO-oxidized cellulose fibers have some interactions with the cationic polymers in the sheets, contributing to their wet strength improvements. Hemiacetals, N-acylcarbinolamines, carbinolamines, and Schiff bases are the possible structures formed at the interfaces between the TEMPO-oxidized cellulose fibers and cationic polymers in the sheets. Repulping behavior of the once-dried sheets was studied as well.

Plant-derived nanostructures: types and applications

“…The purpose of the alkaline treatment is to dissolve and eliminate lignin and hemicellulose from the matrix surrounding the cellulose microfibrils, rendering them vulnerable for isolation of individual microfibers. Oxidative chemical pre-treatment: Oxidation pre-treatment, also known as a TEMPO-mediated oxidation process, deploys radicals emanating from 2,2,6,6tetramethylpi-peridine-1-oxyl (TEMPO) on the substrate prior to the main defibrillation treatment; this technique has proven promising for the surface modification of native celluloses 216,[271][272][273][274][275][276] . Abe et al, 266 produced nanofibers from wood powder, with only one pass through a grinder, following extensive chemical pre-treatment.…”

Effect of cellulose nanofiber dimensions on sheet forming through filtration

“…Over the last two decades, increasing attention has been paid to the synthesis of cellulose nanofibres and their applications in various fields, due to their high strength and stiffness (Eichhorn et al 2010) combined with low weight, biodegradability and renewability (Siró and Plackett 2010). Cellulose nanofiber can be used in several applications such as reinforcement in biocomposites (Trovatti et al 2010;Tunç and Duman 2011;Nakagaito and Yano 2005), strength additive in papermaking (Ahola et al 2008;Saito and Isogai 2006), production of hydrogel (Abe and Yano 2011), anti-microbial films (Andresen and Stenius 2007), and high-technology devices. There are only a few reports on the use of cellulose nanofibers in paper-like applications (Edgar and Gray 2003;Henriksson et al 2008;Nogi et al 2009;Sehaqui et al 2010;Syverud and Stenius 2009;Zhang et al 2010).The term cellulose nanofiber paper has been used to describe a 2D flat material which is made of cellulose nanofibers, including films and sheets.…”

CHAPTER 4. Water-Soluble Antimicrobial Polymers for Functional Cellulose Fibres and Hygiene Paper Products

“…18,19 Meanwhile, antimicrobial agents are also required in these products to protect human beings from being attacked by bacteria or virus. Therefore, functional polymer with synergistic wet-strength and antimicrobial activity is very important for these kinds of hygiene paper products.…”