Some properties of activated mixtures of cellulose with solid sodium hydroxide

Iovleva, M. M.; Смирнова, В. Н.; Belousova, T. A.; Banduryan, S. I.; Калашник, А. Т.; Rudinskaya, G. Ya.

doi:10.1007/bf01057704

Cited by 3 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, the cellulose structure becomes more accessible (Mantanis et al 1995). Various solvents and reagents, e.g., sodium hydroxide (Iovleva et al 1996;Bochek 2003) and a combination of sodium hydroxide and urea (Kunze and Fink 2005), were reported for this purpose.…”

Section: Introductionmentioning

confidence: 99%

Carboxymethylated pulp as starting point to prepare hydroxypropylmethyl cellulose with enhanced gel rheological properties in an aqueous medium

Hamed

Al-Kerm

et al. 2021

BioRes

View full text Add to dashboard Cite

Hydroxypropyl methylcellulose in an aqueous solution upon heating tends to undergo thermal gelation, where the polymer chains form a network and precipitate from solution. This occurs at a temperature known as thermal gelation point. Polymer precipitation causes a significant drop in the shear viscosity. This could be a disadvantage in a hot environment or in applications were heat is applied. In this work, a hydroxypropylmethyl cellulose (HPMC) was formed that undergoes thermal gelation with no polymer precipitation and with enhanced rheological properties. The target HPMC was prepared from wood pulp with a low content of carboxymethyl groups. The produced hydroxypropyl methylcellulose (CMHPMC) derivative showed unique physical properties that are not achievable with typical hydroxypropyl methylcellulose. The thermal gelation temperature of an aqueous solution of CMHPMC was increased from 55 °C for commercial HPMC to 85 °C for CMHPMC. A substitution level of carboxymethylation that led to an HPMC with a thermal gelation and with no precipitation was determined to be a 0.15 of carboxyl groups per anhydroglucose repeat unit. In addition, the carboxymethylated pulp showed an enhanced reactivity towards etherification reactions.

show abstract

Section: Introductionmentioning

confidence: 99%

Carboxymethylated pulp as starting point to prepare hydroxypropylmethyl cellulose with enhanced gel rheological properties in an aqueous medium

Hamed

Al-Kerm

et al. 2021

BioRes

View full text Add to dashboard Cite

show abstract

“…These techniques have focused mainly on chemical degradation (such as hydrolysis and oxidation of raw materials), thermal degradation, mechanical treatments (such as wet/dry milling), and on the swelling of cellulosic materials through the breakage of interfibrillar and intrafibrillar bonds to expose more active surface areas (21). The mixing of cellulose and sodium hydroxide to form alkali cellulose is a typical example of water-based swelling techniques (26). Kunze and Fink (27) described another method based on the combination of sodium hydroxide and urea.…”

Section: Cellulose Accessibility and Reactivitymentioning

confidence: 99%

Production of Dissolving Grade Pulps from Wood and Non-Wood Paper-Grade Pulps by Enzymatic and Chemical Pretreatments

Ibarra

Köpcke

et al. 2012

ACS Symposium Series

View full text Add to dashboard Cite

A raw material with high cellulose content and low content of hemicelluloses, residual lignin, extractives and minerals is required for many important applications in the pharmaceutical, textile, food and paint industries i.e. cotton and dissolving grade pulp are used. However, the high costs for the production of dissolving grade pulps has triggered interest in upgrading paper-grade pulps into dissolving pulps by selective removal of hemicelluloses and subsequent activation of the pulps. This study reports the feasibility to produce dissolving grade pulps from different wood and non-wood paper-grade pulps employing enzymatic and chemical pre-treatments. The results were compared to those of commercial bleached dissolving pulps.

show abstract