Screening of hydrogen bonds in modified cellulose acetates with alkyl chain substitutions

Nilsson, Robin; Olsson, Martina; Westman, Gunnar; Matic, Aleksandar; Larsson, Anette

doi:10.1016/j.carbpol.2022.119188

Cited by 20 publications

(4 citation statements)

References 35 publications

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“…This is probably the reason why instead of pronounced peaks in Figure 3 a, we can see amorphous humps, which are the most affected by the effect of plasticization. Furthermore, intermolecular forces between polymer chains, space occupied by the main chain and side chains the movement of side chains, and density should not be neglected [ 54 ]. In this respect, the plasticizer dramatically changes the hydrogen bonding of the polymer network and affects its corresponding hump ( Figure 3 a).…”

Section: Resultsmentioning

confidence: 99%

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization

Janković,

Kojić,

Milošević

et al. 2023

Polymers

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Thermo-chemical conversion via the pyrolysis of cigarette butt (CB) filters was successfully valorized and upcycled in the pre-carbonization and carbonization stages. The pre-carbonization stage (devolatilization) of the precursor material (cellulose acetate filter, r-CAcF) was analyzed by micro-scale experiments under non-isothermal conditions using TG-DTG-DTA and DSC techniques. The results of a detailed kinetic study showed that the decomposition of r-CAcF takes place via complex mechanisms, including consecutive reaction steps and two single-step reactions. Consecutive stages include the α-transition referred to as a cellulose polymorphic transformation (cellulose I → II) through crystallization mechanism changes, where a more thermodynamically ordered system was obtained. It was found that the transformation rate of cellulose I → II (‘cellulose regeneration’) is strongly affected by the presence of alkali metals and the deacetylation process. Two single-step reactions showed significant overlapping behavior, which involves a nucleation-controlled scission mechanism (producing levoglucosan, gaseous products, and abundant radicals) and hydrolytic decomposition of cellulose by catalytic cleavage of glycosidic bonds with the presence of an acidic catalyst. A macro-scale experiment showed that the operating temperature and heating rate had the most notable effects on the total surface area of the manufactured carbon. A substantial degree of mesoporosity with a median pore radius of 3.1695 nm was identified. The presence of macroporosity on the carbon surface and acidic surface functional groups was observed.

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Section: Resultsmentioning

confidence: 99%

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization

Janković,

Kojić,

Milošević

et al. 2023

Polymers

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“…After purification, the resulting product (named 500R-4H-4.5) was characterized by ATR-IR and 1 H NMR. In the ATR-IR spectrum (Figure b), the characteristic peak of AGU was recorded at 1025–1060 cm –1 . , Compared with MCC, new peaks in the ATR-IR spectra of 500R-4H-4.5 located at 1746 and 1156 cm –1 were associated with the absorption of ester (−COO−) groups. , Also, two distinct characteristic peaks were detected at 2848 and 2918 cm –1 , which represented the stretching vibration of C–H in methyl (−CH 3 ) and methylene (−CH 2 −) groups, respectively. , ATR-IR results indicated that many aliphatic chains were successfully grafted onto cellulose molecules by the proposed mechanochemical esterification. These results were further proved by 1 H NMR analysis (Figure c).…”

Section: Resultsmentioning

confidence: 96%

“…In the ATR-IR spectrum (Figure 1b), the characteristic peak of AGU was recorded at 1025−1060 cm −1 . 43,44 Compared with MCC, new peaks in the ATR-IR spectra of 500R-4H-4.5 located at 1746 and 1156 cm −1 were associated with the absorption of ester (−COO−) groups. 13,38 Also, two distinct characteristic peaks were detected at 2848 and 2918 cm −1 , which represented the stretching vibration of C−H in methyl (−CH 3 ) and methylene (−CH 2 −) groups, respectively.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Efficient Conversion of Cellulose to Thermoplastics by Mechanochemical Esterification

Hou

et al. 2023

ACS Sustainable Chem. Eng.

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Despite the melting processibility of cellulose is of great importance to convert this abundant biomass to various products, the efficient and sustainable preparation of a thermoplastic cellulose material remains a challenge. Herein, we report a novel one-step ball-milling mechanochemistry method for efficiently converting cellulose to melt-processable cellulose stearates (SCEs) without sacrificing excess reagents. By adjusting the reaction conditions, a series of SCEs with degrees of substitution (DS) ranging from 1.30 to 2.37 are synthesized. Besides, the relationship between DS and the thermoplasticity of SCEs is well investigated. The obtained SCEs with DS beyond 1.62 show favorable thermoplasticity, which can be processed into homogeneous films with a maximum tensile strength of 12.4 MPa and an elastic modulus of 353.6 MPa by a conventional hot-pressing technique (160 °C, 10 MPa). Moreover, this method is universally used for achieving various thermoplastic fatty acid cellulose esters with different numbers of carbons (10−18) in side chains. Due to its high efficiency and sustainability, this approach holds great potential for the large-scale fabrication of thermoplastic cellulosebased materials.

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“…CA is a desirable polymer due to its low cost, biocompatibility, biodegradability, and acceptable physical qualities in industry [11][12]. CA is utilized in food packaging, coatings, sealants, and membrane separation [13]. Wood and cotton are the most important material resources for industrial synthesizing CA, although they have a high lignin content which requires more chemicals to remove cellulose [14].…”

Section: ■ Introductionmentioning

confidence: 99%

Synthesis of Cellulose Acetate from Screw Pine (<i>Pandanus tectorius</i>) Leaves for Enhancing Water Permeability and Fouling Resistance of PVDF Membrane

Trisnawati,

Suryanti,

Pramono

et al. 2023

Indones. J. Chem.

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Cellulose derivatives from natural resources continuously develop to find the best hydrophobic polymer-based membrane technology performance. This study was conducted to improve the hydrophilicity, performance, and anti-fouling of polyvinylidene fluoride (PVDF) membrane with cellulose acetate (CA) filler synthesized from screw pine (Pandanus tectorius) leaf cellulose. CA was synthesized by the Fischer esterification mechanism and the PVDF membrane was fabricated using the phase inversion method with 0.3% CA concentration. FTIR analysis of CA shows an absorption at 1700 cm−1 suggesting that the hydroxyl group of cellulose had been successfully substituted with an ester group (C=O), and CA has a high degree of substitution (DS) value of 3.50. Adding CA improved the hydrophilicity and anti-fouling properties of up to 86.45% of PVDF membranes. Furthermore, CA increased the value of water permeability 2–3 times than pristine PVDF membrane. The presence of CA enhanced the porosity of the PVDF membrane, which promoted the membrane's effectiveness for MB filtering. As a result, CA from screw pine leaf cellulose has promising features as a filler for PVDF membranes and potential dye filtration.

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Screening of hydrogen bonds in modified cellulose acetates with alkyl chain substitutions

Cited by 20 publications

References 35 publications

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization

Efficient Conversion of Cellulose to Thermoplastics by Mechanochemical Esterification

Synthesis of Cellulose Acetate from Screw Pine (<i>Pandanus tectorius</i>) Leaves for Enhancing Water Permeability and Fouling Resistance of PVDF Membrane

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