H3PW12O40·4H2O as an efficient catalyst for the conversion of cellulose into partially substituted cellulose acetate

Liao, Chongjing; Fang, Tingting; Luo, Shanshan; Fan, Guozhi; Song, Guangsen

doi:10.1002/app.41212

Cited by 12 publications

(1 citation statement)

References 43 publications

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“…All samples exhibited two major absorbance regions, including regions of 500 cm -1 to 1700 cm -1 and 2800 cm -1 to 3500 cm -1 . The peak at 3344 cm -1 is ascribed to OH stretching vibration (Liao et al 2015). The peak at 1735 cm -1 is associated with the presence of the acetyl and/or uronic ester groups of the hemicellulose (Sain and Panthapulakkal 2006).…”

Section: Ftir Analysismentioning

confidence: 99%

Production of xylose from diluted sulfuric acid hydrolysis of wheat straw

Tian

et al. 2017

BioRes

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The objectives of this study were to generate fermentable xylose by sulfuric acid hydrolysis of wheat straw and investigate the effect of hemicellulose removal on the physical and chemical properties of the unhydrolyzed solid residue (USR). Different reaction conditions, including concentration of sulfuric acid (COS), temperature, and time, were tested for their effects on the yield of xylose and the USR. The ideal hydrolysis conditions for xylose production were 0.5% of COS at 140 °C for 90 min, with the xylose yield of 0.185 g/g wheat straw. The Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses showed that the acid hydrolysis only caused slight changes in the functional groups and the crystal form of wheat straw at mild conditions, while higher temperature or higher COS exacerbated these changes.

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Section: Ftir Analysismentioning

confidence: 99%

Production of xylose from diluted sulfuric acid hydrolysis of wheat straw

Tian

et al. 2017

BioRes

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Molecular Layer Deposition of Thermally Stable Polybenzimidazole‐Like Thin Films and Nanostructures

Ghafourisaleh

Hatanpää

Vihervaara

et al. 2022

Adv Materials Inter

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aliphatic or aromatic derivatives as monomers for optimizing application specific properties for bioactive materials and fuel cell membranes, for example. [17,18] In recent years, with the developments of using insulating polymer materials in electronic devices, needs for high-thermalresistance polymer dielectrics have been increasingly emphasized in order to ensure high reliability of devices operating at high temperatures. [19] While conventional polyethylene and polypropylene possess intrinsically excellent insulating properties, [20] they are facing great challenges in advanced electrical devices due to their limited service temperatures below 105 °C and increased leakage currents at elevated temperatures. [2,20,21] Another prevalent area for PBI lies in membrane applications such as H 2 separation membranes, fuel cells, and redox battery membranes. High intrinsic H 2 selectivity over larger gas molecules, such as CO 2 , N 2 , and CH 4 , was demonstrated with PBI film membranes prepared using flat and hollow polyamide P84 fibers as a support material. [8] PBI has gained great interest also as a membrane material in vanadium redox flow batteries where ion-selectivity for vanadium was obtained with a thin layer of PBI polymer. [22] Polybenzimidazoles and their more complex derivatives are often classified as expensive specialty plastics due to their outstanding properties but also difficulties in manufacturing. PBI plastics are known as the thermally most stable thermoplastics with a glass transition temperature (T g ) higher than 400 °C. [11] In a previous study by Iqbal et al. [19] PBI exhibited excellent thermal stability up to a temperature of 500 °C with a total weight loss of only 15%. The stability of PBI polymers drives from the high number of aromatic rings incorporated in the polymer chain. Aromatic rings are efficiently absorbing both thermal and radiation energy and aid in redistributing the excitation energy throughout the material. [18,19] Conventional PBI polymers are usually prepared via hightemperature polycondensation reactions in either solution or melt to achieve high degree of cyclization. [23][24][25] PBIs are typically synthesized from aromatic tetraamines (bis-o-diamines) and dicarboxylates (acids, esters, or amides) [26] (Scheme 2).PBI thin films are scarcely reported. Previous depositions were carried out either by a casting solution method from formic acid and dimethylsulfoxide (DMSO) solutions or dip-coating and blade-casting methods. [23] The deposition of polybenzimidazole (PBI)-like thin films by molecular layer deposition is reported here for the first time using isophthalic acid (IPA) and 3,3′-diaminobenzidine (DAB) as monomers and trimethylaluminum (TMA) as a linker precursor. Two precursor pulsing sequences are tested, the ABCB (TMA + IPA + DAB + IPA) and ABC (TMA + IPA + DAB) type MLD processes result in different types of PBI-like films. With the ABCB sequence thin film growth per cycle (GPC) of 6.0 Å is obtained at 225-280 °C, whereas GPC of 7.0 Å is obtained with the ABC s...

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Preparation of microcrystalline cellulose from rice straw under microwave irradiation

Fan

Wang

Song

et al. 2017

J of Applied Polymer Sci

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Crude cellulose was isolated from rice straw and then converted into microcrystalline cellulose (MCC) via partial hydrolysis. Both the isolation and partial hydrolysis were carried out under microwave. Rice straw was successively pretreated with alkaline and acid solutions before hydrolysis. Lignin and silica were almost removed but partial removal of hemicellulose in dilute alkali solution, and the residual hemicellulose was further removed in dilute acid solution. The total removal rates of hemicellulose, lignin and silica reached up 92.0%, 98.5%, and 96.8%, respectively. The cellulose content of 93.6 wt % in MCC was given by partial hydrolysis of crude cellulose isolated from rice straw. The comparison between microwave irradiation and traditional heating method was also investigated. Compared to traditional heating method, similar results were obtained while milder conditions, including shorter time and lower temperature, were required. An effective microwave‐assisted and energy‐efficient methodology using rice straw as the alternative source of cellulose fiber was developed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44901.

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H₃PW₁₂O₄₀·4H₂O as an efficient catalyst for the conversion of cellulose into partially substituted cellulose acetate

Cited by 12 publications

References 43 publications

Production of xylose from diluted sulfuric acid hydrolysis of wheat straw

Production of xylose from diluted sulfuric acid hydrolysis of wheat straw

Molecular Layer Deposition of Thermally Stable Polybenzimidazole‐Like Thin Films and Nanostructures

Preparation of microcrystalline cellulose from rice straw under microwave irradiation

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