Functionalisation of cellulosic substrates by a facile solventless method of introducing carbamate groups

Vo, Loan T.T.; Široká, Barbora; Manian, Avinash P.; Bechtold, Thomas

doi:10.1016/j.carbpol.2010.06.052

Cited by 33 publications

(23 citation statements)

References 12 publications

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“…Similar observations were previously reported in which cellulose in aqueous suspension is known to have a general tendency to aggregate in parallel with each other (Wright et al 1987). The agglomeration in cellulose membranes may be due to the surface ionic charge of the cellulose (Vo et al 2010). However, there was no substantial difference in morphology of the cellulose membrane as the amount cellulose used to dissolve increases.…”

Section: Viscosity Of Cellulose Solutionssupporting

confidence: 88%

Synthesis of Liquid Hot Water Cotton Linter to Prepare Cellulose Membrane using NaOH/Urea or LiOH/Urea

Gan¹,

Padzil²,

Zakaria³

et al. 2015

BioResources

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The liquid hot water (LHW) pretreatment on cotton linter (CL) was carried out using an autoclave heated in a hot oil bath. The LHW pretreated CL (LCL) was dissolved in NaOH/urea and LiOH/urea aqueous solutions and subsequently used to produce cellulose membrane. The effects of LHW pretreatment, amount of cellulose, and type of alkaline solvent on properties of cellulose solution and cellulose membrane were studied.The formation of cellulose II and crystallinity index (CrI) on the cellulose membranes were confirmed by X-ray diffraction (XRD). The morphology of cellulose membranes were observed by field emission scanning electron microscopy (FESEM). The LHW pretreatment resulted in higher cellulose solubility, higher cellulose solution viscosity, and improved properties of regenerated cellulose products compared to non-treated cellulose. Results also revealed that the amount of cellulose used affected the solubility and viscosity of the cellulose solution and the higher dissolving power of the LiOH/urea system as compared to the NaOH/urea system. In fact, higher solubility and viscosity properties are key factors in many cellulose applications such as membranes, fibers, hydrogels, and other regenerated cellulose products.

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Section: Viscosity Of Cellulose Solutionssupporting

confidence: 88%

Synthesis of Liquid Hot Water Cotton Linter to Prepare Cellulose Membrane using NaOH/Urea or LiOH/Urea

Gan¹,

Padzil²,

Zakaria³

et al. 2015

BioResources

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show abstract

“…Cellulose contains specific structure that tends to arrange of the polymer chains into tightly packed, highly crystalline structures that are water insoluble and resistant to depolymerization (Carpita & Gibeaut, 1993). Solubility of cellulose is also an issue since its solubility varies with its molecular weight and is limited (El-Wakil & Hassan, 2008;Vo,Široká, Manian, & Bechtold, 2010). Therefore, the aim of the pretreatment is to disrupt the lignin seal and dislocate the crystalline structure of cellulose .…”

Section: Introductionmentioning

confidence: 99%

Effect of hydrothermal pretreatment on solubility and formation of kenaf cellulose membrane and hydrogel

Gan

Zakaria

Chia

et al. 2015

Carbohydrate Polymers

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“…The drastic change in pH may be caused by ammonia, which is a decomposition product of urea and also a byproduct in the carbamation of cellulose at high temperatures . The carbamate group resulting from the reaction between cellulose and urea would have a characteristic band at

\overset{ν}{true}

≈1713 cm −1 , but in this case it overlaps with the strong carbonyl absorptions discussed earlier and is, thus, undetectable. The formation of carbamate, ammonia, or both in the reaction was studied by elemental analysis.…”

Section: Resultsmentioning

confidence: 92%

Anionically Stabilized Cellulose Nanofibrils through Succinylation Pretreatment in Urea–Lithium Chloride Deep Eutectic Solvent

et al. 2016

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Deep eutectic solvents (DESs) are green chemicals that have the potential to replace traditional solvents in chemical reactions. In this study, urea-LiCl DES was used successfully as a reaction medium in the anionic functionalization of wood cellulose with succinic anhydride. The effects of reaction temperature and time on the carboxyl content and yield were evaluated. The analyses of the degree of polymerization and crystallinity revealed that the DES was a nondegrading and nondissolving reaction medium. Three samples with the highest carboxyl contents were further nanofibrillated with a microfluidizer to diameters of 2-7 nm, as observed by atomic force microscopy. Samples treated at 70-80 °C for 2 h gave the best outcome and resulted in highly viscose and transparent gels. The sample treated at 90 °C contained larger nanoparticles and larger aggregates owing to the occurrence of possible side reactions but resulted in better thermal stability.

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Functionalisation of cellulosic substrates by a facile solventless method of introducing carbamate groups

Cited by 33 publications

References 12 publications

Synthesis of Liquid Hot Water Cotton Linter to Prepare Cellulose Membrane using NaOH/Urea or LiOH/Urea

Synthesis of Liquid Hot Water Cotton Linter to Prepare Cellulose Membrane using NaOH/Urea or LiOH/Urea

Effect of hydrothermal pretreatment on solubility and formation of kenaf cellulose membrane and hydrogel

Anionically Stabilized Cellulose Nanofibrils through Succinylation Pretreatment in Urea–Lithium Chloride Deep Eutectic Solvent

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