Paper conservation with an aqueous NaOH/urea cellulose solution

Li, Yan; Liu, Zhenxing; Shen, Guopeng; Zhan, Yanhui

doi:10.1007/s10570-019-02375-3

Cited by 23 publications

(7 citation statements)

References 19 publications

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“…In addition, a broader peak at 16.08° can also be observed, which can be attributed to the overlapping of (11̅0) and (110) planes. These diffraction peaks are the characteristic planes of cellulose I. ,− On the other hand, the diffraction pattern of cellulose–NaOH (Figure b) has three characteristic peaks at 12.73° (11̅0), 20.28° (110), and 21.38° (020), which belong to cellulose II. It is apparent that the dissolution and reprecipitation of cellulose in the NaOH–urea system at low temperatures transform cellulose I into cellulose II. ,− Different phases of cellulose were observed for the cellulose–NH 4 OH system (Figure c).…”

Section: Resultsmentioning

confidence: 99%

Nitrogen-Doped Carbon Aerogels Prepared by Direct Pyrolysis of Cellulose Aerogels Derived from Coir Fibers Using an Ammonia–Urea System and Their Electrocatalytic Performance toward the Oxygen Reduction Reaction

Fauziyah

Widiyastuti

Setyawan

2020

Ind. Eng. Chem. Res.

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In this paper, a new method using an ammonia–urea system was proposed to prepare cellulose aerogels from coir fibers as the starting material for non-ordered porous nitrogen-doped carbon aerogels. Direct pyrolysis of the as-prepared carbon aerogels has successfully produced nitrogen-doped carbon aerogels using the cellulose aerogel derived from the nitrogen-rich coir fibers. The as-prepared carbon aerogel inherits the three-dimensional nonordered porous network of the cellulose aerogel, maintaining its high specific surface area (SSA) and the large pore volume. In addition, the honeycomb-like structure of internal pores in individual fibers could also be maintained, and the pores are even larger than those of the corresponding cellulose aerogel. In the ammonia–urea system, ammonia not only served as an agent to assist the cellulose dissolution but also played an important role in exfoliating the carbon aerogel to form defects that cause a few layer disorders. The defects caused the SSA and the pore volume of the aerogel to increase significantly after carbonization. The surface area increased from approximately 70 to 3730 m2/g and the pore volume from 0.54 to 4.20 cm3/g. The porous nitrogen-doped carbon aerogel showed excellent electrocatalytic activity toward the oxygen reduction reaction (ORR) in alkaline media following a two-electron-transfer mechanism.

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Section: Resultsmentioning

confidence: 99%

Nitrogen-Doped Carbon Aerogels Prepared by Direct Pyrolysis of Cellulose Aerogels Derived from Coir Fibers Using an Ammonia–Urea System and Their Electrocatalytic Performance toward the Oxygen Reduction Reaction

Fauziyah

Widiyastuti

Setyawan

2020

Ind. Eng. Chem. Res.

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“…By catalytic reaction, the epoxy cyclohexane homopolyether was synthesized between the catalyst boron trifluoride ether and the initiator glycol. The reaction mechanism of polymerization is similar to that of the cationic ring-opening polymerization of epoxy compounds [6,26]. The reaction mechanism is as follows: Glycol reacts with boron trifluoride ether, and the intermediate product that is generated reacts with epoxy cyclohexane to form an oxonium ion with a positive charge at the active center [20].…”

Section: The Reaction Mechanism Of Epoxy Cyclohexane Homopolyethermentioning

confidence: 99%

Preparation and Application of Polyurethane Coating Material Based on Epoxy Cyclohexane Protective for Paper

Liu

Jin

et al. 2021

Coatings

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Paper is important to most historical and cultural relics, however, these paper heritages are facing a crisis of disappearance, damage and aging. For increasing the paper strength, delaying the paper aging, and improving the weak stability and permeability of former resins used for paper, another material is necessary to be produced on preservation and protection of the paper items. The synthesis of epoxy cyclohexane polyetherpolyol was as follows: Epoxy cyclohexane was as the starting material, ethylene glycol was as the initiator, boron trifluoride ether was as catalyst, and dichloromethane was as the solvent. The synthesized homopolyether was characterized by infrared (IR) spectroscopy and proton nuclear magnetic resonance (1HNMR) spectroscopy to determine the structure. Then the epoxy cyclohexane homopolyether reacted with the hexamethylene diisocyanate (HDI) trimer, and the polyurethane was obtained. With the tests of the physical and chemical properties of paper samples, it showed that the paper processed with 10% polyurethane liquid had excellent performance, the increase in the tensile strength was from 1105 to 2317 N/m, and the increase in the folding endurance was from 20 to 504 times. What’s more, the paper processed with 10% polyurethane liquid had good brightness and gloss. The results of the paper samples for the test have shown that the synthesized material simultaneously has the advantages of epoxy cyclohexane homopolyether and polyurethane, possessing excellent performance in paper reinforcement. Thus, the synthesized polyurethane material has broad application prospect in paper protection field.

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“…The ring-opening polymerization for generating CHO-THF copolyether takes place by the reactants CHO and THF, in the catalysis of boron trifluoride diethyl etherate, solvent of dichloromethane, initiation of glycerol [22,31]. In the chain initiation stage, an intermediate is generated by the combination of boron trifluoride diethyl etherate and glycerol, which then reacts with CHO.…”

Section: The Reaction Mechanism Of Cho-thf Copolyethermentioning

confidence: 99%

Preparation and Application of Polyurethane Coating Material Based on Epoxycyclohexane-Tetrahydrofuran in Paper Conservation

Liu

Jin

et al. 2021

Coatings

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Paper cultural heritages are valuable historical records and also abound in cultural resources. Due to its organic property, paper is susceptible to aging, destruction by environmental pollution and human factors. At present, many countries in the world are facing the problem of paper conservation. Coating reinforcement is one of the methods for paper conservation, in which the choice of reinforcing resin is key. A transparent polyurethane, based on epoxycyclohexane (CHO)-tetrahydrofuran (THF) copolyether, was adopted in this study. The ring-opening polymerization for generating the CHO-THF copolyether took place by the reactants CHO and THF, in the catalysis of boron trifluoride diethyl etherate, initiation of glycerol. Characterizations of the synthetic copolyether were conducted by infrared (IR) spectroscopy and proton nuclear magnetic resonance (1HNMR) spectroscopy. The transparent polyurethane was then produced by the CHO-THF copolyether and hexamethylene diisocyanate (HDI) trimer. The influences of different concentrations of polyurethane solution upon the paper tensile strength, elongation, folding endurance, tearing strength, gloss, and brightness were studied. These findings suggest that 10% polyurethane solution is optimal, not only for greatly improving the paper performance, but also for keeping with the principle of “repair as old”. The applied results demonstrate that the polyurethane based on the CHO-THF copolyether has the characteristics of copolyether along with polyurethane, displaying good mechanical properties in paper reinforcement.

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Paper conservation with an aqueous NaOH/urea cellulose solution

Cited by 23 publications

References 19 publications

Nitrogen-Doped Carbon Aerogels Prepared by Direct Pyrolysis of Cellulose Aerogels Derived from Coir Fibers Using an Ammonia–Urea System and Their Electrocatalytic Performance toward the Oxygen Reduction Reaction

Nitrogen-Doped Carbon Aerogels Prepared by Direct Pyrolysis of Cellulose Aerogels Derived from Coir Fibers Using an Ammonia–Urea System and Their Electrocatalytic Performance toward the Oxygen Reduction Reaction

Preparation and Application of Polyurethane Coating Material Based on Epoxy Cyclohexane Protective for Paper

Preparation and Application of Polyurethane Coating Material Based on Epoxycyclohexane-Tetrahydrofuran in Paper Conservation

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