Carboxymethylcellulose (CMC) as a model compound of cellulose fibers and polyamideamine epichlorohydrin (PAE)–CMC interactions as a model of PAE–fibers interactions of PAE‐based wet strength papers

Abstract

Carboxymethylcellulose (CMC) is a cellulose derivative obtained by the carboxymethylation of some hydroxyl groups in the cellulose macromolecules. In this article, we use CMC as a model compound of cellulose fibers to study polyamineamide epichlorohydrin (PAE)-fibers interactions during the preparation of PAE-based wet strength papers. The main advantages of the use of CMC to replace cellulose fibers are its water-soluble character and the homogeneous reaction medium during mixing with PAE resin. Based on 13 C cross-polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR) and Fourier transformed infra-red (FTIR) spectroscopy, we prove the formation of ester bonds in PAE-CMC films boosted by a thermal posttreatment at 105 C for 24 h. These ester bonds are derived from a thermally induced reaction between carboxyl groups in the CMC structure and azetidinium ions (AZR) in the PAE resin. PAE-based handsheets were prepared from 100% Eucalyptus fibers. After preparation, some samples were thermally posttreated (TP) at 130 C for 10 min and stored under controlled conditions (25 C and 50% relative humidity or RH). For lowest PAE dosage, storage of the not thermally posttreated (NTP) PAE-based handsheets does not allow them to reach the tensile strength values of TP PAE-based handsheets (at 130 C for 10 min), but the difference in terms of breaking length remains low. For the highest PAE addition level, NTP and TP PAE-based handsheets exhibit close values of the breaking length from 30 days of storage under controlled conditions (25 C and 50% RH). When a thermal posttreatment is applied, the wet strength development of PAE-based papers is a combined effect of homo-and co-cross-linking mechanisms.

Surface treatment of cellulose nanocrystals (CNC): effects on dispersion rheology

“…In the review by Espy (1995) it is stated that alcohol groups may play a part in cross-linking reactions as well as carboxylate end groups of cellulosic polymers. Other reports of the chlorohydrin-azetidinium salts reactivity in PAE are that carboxymetylated cellulose (CMC) or other carboxyl-bearing polymers showed an increased effectiveness in reaction with PAE (Siqueira et al 2015). Also, Obokata and Isogai (2007) have commented in their study on PAE that TEMPO-oxidized cellulose under alkaline conditions showed an increased reactivity toward PAE resulting in increased wet strength in cellulose sheets.…”

Increased thermal stability of nanocellulose composites by functionalization of the sulfate groups on cellulose nanocrystals with azetidinium ions

“…Reagents that react with the sulfate groups of polysaccharides are less explored; however, they may be useful and may have an impact in biological, medicinal, and material applications. From previous research, it is known that azetidinium salts react preferentially with carboxylates, amines, phenols, and phosphorus nucleophiles . Azetidinium salts are positively charged, which to some extent governs their adsorption to carboxylic acids via electrostatic interaction.…”

A novel polyamidine-grafted carboxymethylcellulose: Synthesis, characterization and flocculation performance test

“…The EA results of AN, NVF, CMC, and the new flocculant (CMC-g-PAMD) were given in Table 1. It was apparent from the table that the C, H, O and N contents of the bands at 3262 and 1382 cm -1 were corresponding to N-H and C-N stretching vibration peaks in amide group respectively, and a stretching vibration peak of C=O appeared at 1669 cm -1 (31). For the AN spectrum in Figure 2b, the peak at 2228 cm -1 (AN) confirmed the existence of C≡N (32).…”