Solvent-Free Synthesis of Amidated Carboxymethyl Cellulose Derivatives: Effect on the Thermal Properties

Abstract

The present work explores the possibility of chemically modifying carboxymethyl cellulose (CMC), a widely diffused commercial cellulose ether, by grafting of hydrophobic moieties. Amidation of CMC, at high temperature and in heterogeneous conditions, was selected as synthetic tool for grafting on CMC a panel of commercially available amines (bearing long aliphatic chains, alkyl aromatic and heteroaromatic groups, more or less spaced from the cellulose backbone). The reaction was successfully carried out in absence of solvents, catalysts and coupling agents, providing a promising and more sustainable alternative to conventional amidation procedures. Relationships between the chemical structure of the obtained CMC derivatives and their thermal properties were carefully studied, with a particular attention to the thermal behavior. Grafting of aromatic and heteroaromatic alkyl amines, presenting a linear alkyl chain between CMC backbone and a terminal bulky moiety, allowed for efficiently separating the polysaccharide chains, improving their mobility and resulting in a consequent lowering of the glass transition temperature (Tg). The Tg values obtained (90–147 °C) were found to be closely dependent on both the size of the aliphatic spacer, the structure of the aromatic ring and the extent of amidation.

Biocompatible nanocarriers for passive transdermal delivery of insulin based on self-adjusting N-alkylamidated carboxymethyl cellulose polysaccharides

“…The peaks of the original CMC were found to be in accordance with those reported in previous publications. 54 The new appearing peaks of the modified CMC-6 or CMC-12, correlate with FTIR 55,56 and 1 H-NMR 35,56 data of previously reported modified polysaccharides. Both characterizations methods verify the formation of new secondary amide bonds confirming N-alkylamide CMC modifications.…”

A review of Polyvinyl alcohol / Carboxiy methyl cellulose (PVA/CMC) composites for various applications

“…One of the important derivatives of cellulose is CMC, in which carboxylic groups (-CH 2 -COOH) are bound to some OH groups of natural cellulose [50,51]. According to the literature, the introduction of CMC into the PVA matrix results in the improvement of this polymer properties [52].…”

Controlled Removal of Surfactants from Double‐Walled Carbon Nanotubes for Stronger p‐Doping Effect and Its Demonstration in Perovskite Solar Cells

“…Nevertheless, there have been many reports on CMC degradation and sublimation at ≈300 °C during thermogravimetric analysis (TGA). [ 36–39 ] It has also been reported that the cellulose component of CMC decomposes at ≈350 °C. [ 40 ] Indeed, our TGA indicates that the CMC powder reduces to carbon fragments at a temperature slightly below 300 °C, both in air and in Ar (Figure 1b).…”