Reductive Amination of Dialdehyde Cellulose: Access to Renewable Thermoplastics

Abstract

The reductive amination of dialdehyde cellulose (DAC) with 2-picoline borane was investigated for its applicability in the generation of bioderived thermoplastics. Five primary amines, both aliphatic and aromatic, were introduced to the cellulose backbone. The influences of the side chains on the course of the reaction were examined by various analytical techniques with microcrystalline cellulose as a model compound. The obtained insights were transferred to a 39%-oxidized softwood kraft pulp to study the thermal properties of thereby generated high-molecularweight thermoplastics. The number-average molecular weights (M n ) of the diamine celluloses, ranging from 60 to 82 kD, were investigated by gel permeation chromatography. The diamine celluloses exhibited glass transition temperatures (T g ) from 71 to 112 °C and were stable at high temperatures. Diamine cellulose generated from aniline and DAC showed the highest conversion, the highest T g (112 °C), and a narrow molecular weight distribution (D̵ of 1.30).

High Internal Phase Emulsion Stabilization through Restricted Interdrop Fusion across Water Drainage Channels

“…The characteristic peak at 1740 cm –1 is attributed to the stretching vibration of the aldehyde groups (CO) on BCNF DA . , The absorption bands in the 1640–1690 cm –1 region correspond to the stretching and vibration of the imine groups (CN) of BCNF diC18 . The actual amount of grafted alkyl chains onto BCNF diC18 was measured using the oxime titration method − (Table S1). We could obtain the average grafting yield of alkyl chains by 75.62 (±14.14)%.…”

Solventless Amination of Lignin and Natural Phenolics using 2‐Oxazolidinone

“…The octanal (Sigma Aldrich) and 2‐methylpyridine borane (Sigma Aldrich) were added in a molar ratio of 2 and 2, respectively between the reagent amount and amine amount. The reaction was performed at 45 °C for 24 h. After then, the lignin was washed by the aqueous methanol and distilled water [52] . All modified samples were dried in the oven at 50 °C before the analysis.…”

“…The reaction was performed at 45 °C for 24 h. After then, the lignin was washed by the aqueous methanol and distilled water. [52] All modified samples were dried in the oven at 50 °C before the analysis.…”

Debugging periodate oxidation of cellulose: Why following the common protocol of quenching excess periodate with glycol is a bad idea

“…After isolation of the periodate-oxidised polysaccharide, the DO was determined accurately based on the quantitative oximation reaction with hydroxylamine hydrochloride. The DO was either calculated from the nitrogen content using a previously reported formula (Simon et al, 2023) or by potentiometric titration of the formed hydrochloric acid following our previously adjusted protocol (Simon et al, 2022;Zhao & Heindel, 1991). Each DO was determined at least in duplicate.…”

“…In addition, DAC is not only used directly but also converted into derivatives by follow-up chemistry. The aldehyde groups were further reduced to dialcohol cellulose (Kasai et al, 2014;Larsson et al, 2014a;Lei & Feng, 2020), oxidised to dicarboxy cellulose (Maekawa & Koshijima, 1984;Sharma et al, 2017;Varma & Chavan, 1995a), crosslinked with biopolymers (Kanth et al, 2009;Kim et al, 2017;Koshani, Tavakolian, and van de Ven, 2021;Münster et al, 2018), aminated (Dash et al, 2012;Guigo et al, 2014;Lindh et al, 2016;Simon et al, 2023;Sirviö et al, 2013), and derivatised by Schiff-base reactions (Keshk et al, 2015;Kim & Kuga, 2001).…”