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Yiqi Yang - One of the best experts on this subject based on the ideXlab platform.
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preparation of lightweight polypropylene composites reinforced by Cotton Stalk fibers from combined steam flash explosion and alkaline treatment
Journal of Cleaner Production, 2014Co-Authors: Xiuliang Hou, Fangfang Sun, Dandan Yan, Zhen Dong, Yiqi YangAbstract:Abstract A new method of combined steam flash-explosion and alkaline treatment (SFE-AT) was developed to extract cellulose fibers from bark of Cotton Stalks, and lightweight composites with favorable properties were made from the obtained fibers and polypropylene (PP). It was reported that the cellulose fibers from bark of Cotton Stalks had higher mechanical properties than those from most lignocellulosic byproducts. However, conventional method of using strong alkaline condition (30–100 g/L NaOH) for extraction of cellulose fibers from lignocellulosic byproducts led to environmental pollution and high cost. In this study, bark of Cotton Stalks were treated using three methods, including alkaline treatment (AT), steam flash-explosion (SFE) and SFE-AT. The different Cotton Stalk fibers were blended with PP fibers and compression-molded into composites under optimized conditions (temperature of 170 °C, pressure of 3 MPa, 4 min). The results showed that PP composites reinforced by Cotton Stalk fibers from SFE-AT had the best mechanical properties and stability to water, attributing to the largest surface area and highest cellulose content of Cotton Stalk fibers by SFE-AT. SFE could separate bark of Cotton Stalks with high efficiency and subsequent mild AT could sufficiently remove the non-cellulose impurities by using NaOH solution with concentration as low as 5 g/L. Ultra-lightweight PP composites with the bulk density of 0.27 g/cm3 could be prepared with Cotton Stalk fibers by SFE-AT. Overall, the method of SFE-AT with high efficiency and low cost could be very useful in exploring industrial applications of bark of Cotton Stalks and other lignocellulosic byproducts.
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chemical free extraction of Cotton Stalk bark fibers by steam flash explosion
Bioresources, 2014Co-Authors: Xiuliang Hou, Fangfang Sun, Li Zhang, Jun Luo, Yiqi YangAbstract:Cotton Stalk bark fibers (CSBF) were extracted by steam flash explosion, completed within 0.09 s, and the extracted fibers were compared with those obtained by conventional alkaline treatment. Results indicate that the optimum steam pressure was 2.5 MPa when steaming time was set to 2 min for extracting CSBF. Under the optimized conditions, the obtained CSBF had a cellulose content of 72%, length of 48 mm, fineness of 45 dtex, crystallinity index of 68, moisture regain of 8%, water retention of 98%, and tensile strength of 2.4 cN/dtex, which were similar to results obtained by conventional alkaline treatment. Compared with bark of Cotton Stalks, CSBF had lower moisture regain and water retention, and higher onset decomposition temperature. The results show that moderate steam flash explosion is a chemical-free, quick, and effective method for exploring the industrial applications of bark of Cotton Stalks as natural cellulose fibers.
Hanping Chen - One of the best experts on this subject based on the ideXlab platform.
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solar pyrolysis of Cotton Stalk in molten salt for bio fuel production
Energy, 2019Co-Authors: Yingpu Xie, Haiping Yang, Kuo Zeng, Gilles Flamant, Nian Liu, Xinyi Yang, Ange Nzihou, Hanping ChenAbstract:Abstract Solar pyrolysis of Cotton Stalk was carried out in a molten salt reactor heated by 4 kW solar simulator. The effects of pyrolysis temperature and mass ratio of molten salt to biomass on pyrolysis products properties were investigated. The use of molten salt as pyrolysis media increased gas yield. At 850 °C, the gas yield (mainly of CO and H2) continued to rise from 41.35 wt% to 82.57 wt% when mass ratio of molten salt to Cotton Stalk increased from 0 to 10. Pyrolysis in molten salt significantly decreased bio-oil acids and phenols, while increased aromatics among pyrolysis temperature range of 450–850 °C. There was positive correlation between the increased content of aromatics and mass ratio of molten salt to Cotton Stalk (from 0.5 to 10). The bio-char carbon content showed a general decreasing trend while oxygen, BET surface area and pore volume increased with using molten salt as pyrolysis media. Bio-char obtained from CS1MS5 pyrolysis at 850 °C had the highest BET surface area of 972.57 m2/g and the biggest total pore volume of 0.6203 cm3/g. High quality pyrolysis products with more uniform chemistry suggest catalytic reactions occur inside the solar reactor due to the intermediates degradation with molten salt.
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effects of temperature and mg based additives on properties of Cotton Stalk torrefaction products
Energy & Fuels, 2018Co-Authors: Kuo Zeng, Haiping Yang, Xianhua Wang, Qing Yang, Qinfeng Che, Yang Zhang, Sebastian Wright, Hanping ChenAbstract:In a new development, Mg-based additives were introduced to the process of torrefaction of Cotton Stalk to enhance the deoxygenation effect. The properties of torrefaction products obtained using temperatures in the range 200–350 °C and three different types of Mg-based additives (MgO, MgO-K2CO3, and MgO-KNO3-NaNO3) with varied mass ratios (0.5, 1, and 2) were characterized. The yield of solid product significantly declined from 92.02% to 36.95% when the torrefaction temperature rose from 200 to 350 °C, while gas and liquid yields increased to 24.90% and 38.15%, respectively. MgO-K2CO3 was the most effective additive because it not only promoted deoxygenation in the solid product (oxygen content decreased by about 43%) but also reduced the loss of hydrogen. CO2 was the main gas component, and production was promoted as the Mg-based additive mass ratio rose from 0.5 to 2. The phenol and ketone content in the liquid product significantly increased, while the acid content decreased. Biomass torrefaction with...
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influence of torrefaction with mg based additives on the pyrolysis of Cotton Stalk
Bioresource Technology, 2018Co-Authors: Kuo Zeng, Haiping Yang, Xianhua Wang, Jingai Shao, Qing Yang, Yang Zhang, J S Li, Hanping ChenAbstract:Abstract The study presented an approach to introduce Mg-based additives into Cotton Stalk for strengthening deoxygenation effect during torrefaction. Then catalytic pyrolysis of torrefied feedstock with Mg-based additives residue as catalyst was performed at 550 °C for 10 min in a fixed-bed reactor. The effects of torrefaction temperature (200, 230, 260, 290, 320, 350 °C), type of Mg-based additive (MgO and MgO-K 2 CO 3 ), mass ratio of additive to biomass (0.5, 1 and 2) on pyrolysis were investigated. The results indicated that yields of bio-char and bio-oil significantly increased and decreased with torrefaction temperature rising to 350 °C. MgO inhibited pyrolysis bio-char yield increase with torrefaction severity. MgO-K 2 CO 3 increased H 2 yield a lot from 1.39 to 3.67 mmol/g. It also effectively improved the aromatic hydrocarbons in bio-oil and the reduction of acids. A maximum aromatic hydrocarbons yield of 16.05% was obtained with MgO-K 2 CO 3 (the mass ratio of 0.5:1) at torrefaction temperature of 320 °C.
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Effects of Temperature and Mg-Based Additives on Properties of Cotton Stalk Torrefaction Products
2018Co-Authors: Kuo Zeng, Haiping Yang, Xianhua Wang, Qing Yang, Qinfeng Che, Yang Zhang, Sebastian Wright, Hanping ChenAbstract:In a new development, Mg-based additives were introduced to the process of torrefaction of Cotton Stalk to enhance the deoxygenation effect. The properties of torrefaction products obtained using temperatures in the range 200–350 °C and three different types of Mg-based additives (MgO, MgO-K2CO3, and MgO-KNO3-NaNO3) with varied mass ratios (0.5, 1, and 2) were characterized. The yield of solid product significantly declined from 92.02% to 36.95% when the torrefaction temperature rose from 200 to 350 °C, while gas and liquid yields increased to 24.90% and 38.15%, respectively. MgO-K2CO3 was the most effective additive because it not only promoted deoxygenation in the solid product (oxygen content decreased by about 43%) but also reduced the loss of hydrogen. CO2 was the main gas component, and production was promoted as the Mg-based additive mass ratio rose from 0.5 to 2. The phenol and ketone content in the liquid product significantly increased, while the acid content decreased. Biomass torrefaction with Mg-based additives not only produced a low oxygen content solid product but also improved the properties of the byproducts (gas and liquid) so that they could be recovered and utilized as fuel or chemicals
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fast pyrolysis of Cotton Stalk biomass using calcium oxide
Bioresource Technology, 2017Co-Authors: Xu Chen, Yingquan Chen, Haiping Yang, Xianhua Wang, Wei Chen, Hanping ChenAbstract:Abstract We herein investigate the various roles of calcium oxide in the pyrolysis of biomass at a variant temperatures. The evolution of pyrolysis products was examined to propose the various roles of Ca at a range of temperatures and CaO addition ratios with Cotton Stalk on a fixed-bed reactor. We found that upon the addition of CaO, the content of ketones produced increased, while that of acidic compounds decreased. Under similar conditions, the concentration of evolved H 2 and CH 4 increased, while that of CO 2 decreased. Thus, variation in the CaO/biomass (Ca/B) mass ratios and pyrolysis temperatures indicated that CaO could act as a reactant, an absorbent, and a catalyst at Ca/B ratios of 0.2, and >0.4, respectively. Moreover, at temperatures >600 °C, the roles of CaO as an absorbent and a reactant were less apparent, while its role as a catalyst was enhanced.
Praveen Kumar Keshav - One of the best experts on this subject based on the ideXlab platform.
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Lignocellulosic ethanol production from Cotton Stalk: an overview on pretreatment, saccharification and fermentation methods for improved bioconversion process
Biomass Conversion and Biorefinery, 2021Co-Authors: Praveen Kumar Keshav, Chandrashekhar Banoth, Srinivas Naik Kethavath, Bhima BhukyaAbstract:Cotton Stalk is the most widely generated agricultural residue with lower economic importance, and can be employed as a feedstock in lignocellulosic biorefinery for the manufacture of bioethanol and other value-added bioproducts. Cotton Stalk possesses high holocellulose content, which can be saccharified to various fermentable sugars for bioethanol production. However, the occurrence of high amount of lignin in Cotton Stalk renders it an inferior substrate for bioethanol production. Selection of suitable pretreatment process can improve digestibility of Cotton Stalk and hence higher sugar concentration on subsequent enzymatic saccharification. Furthermore, fermentation of hexose and pentoses sugars to ethanol requires robust microbial strains and efficient fermentation methods. Therefore, the major hindrance in commercializing lignocellulosic ethanol from Cotton Stalk is to develop an effective combination of pretreatment, saccharification, and fermentation methods thereby making the whole bioconversion process economically viable. This review paper discusses various previously investigated pretreatment, acid and/or enzymatic saccharification, and fermentation methods for Cotton Stalk-to-lignocellulosic ethanol production . Finally, it also discusses the major barriers in bioethanol fermentation strategies, and as well future perspectives to overcome these issues.
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Sequential acid and enzymatic saccharification of steam exploded Cotton Stalk and subsequent ethanol production using Scheffersomyces stipitis NCIM 3498
Industrial Crops and Products, 2018Co-Authors: Praveen Kumar Keshav, Chandrasekhar Banoth, Archana Anthappagudem, Venkateswar Rao Linga, Bhima BhukyaAbstract:Abstract The present study was mainly focused on effective utilization of holocellulose content of Cotton Stalk for bioethanol production. Steam exploded Cotton Stalk (180 °C for 5 min; severity factor- 3.05) was subjected to sequential acid and enzymatic saccharification. Acid saccharification (1.5% H2SO4 at 110 °C for 60 min) of steam exploded Cotton Stalk released maximum of 37.24 ± 1.20 g/L reducing sugars with 69.16 ± 1.18% holocellulose hydrolysis. Subsequent enzymatic saccharification of steam exploded acid treated residue yielded maximum 8.50 ± 0.57 g/L sugar concentration with 84.20 ± 0.34% combined saccharification efficiency using 20 FPU/g cellulase loading (Accellerase- 1500) after 72 h incubation period. Finally, batch fermentation of mixed (acid-enzymatic) hydrolysate containing 45.74 ± 1.68 g/L sugars with Scheffersomyces stipitis NCIM 3498 produced 19.08 ± 0.56 g/L ethanol with 0.47 g/g ethanol yield after 48 h time period.
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improved enzymatic saccharification of steam exploded Cotton Stalk using alkaline extraction and fermentation of cellulosic sugars into ethanol
Bioresource Technology, 2016Co-Authors: Praveen Kumar Keshav, Shaik Naseeruddin, Venkateswar L RaoAbstract:Abstract Cotton Stalk, a widely available and cheap agricultural residue lacking economic alternatives, was subjected to steam explosion in the range 170–200 °C for 5 min. Steam explosion at 200 °C and 5 min led to significant hemicellulose solubilization (71.90 ± 0.10%). Alkaline extraction of steam exploded Cotton Stalk (SECOH) using 3% NaOH at room temperature for 6 h led to 85.07 ± 1.43% lignin removal with complete hemicellulose solubilization. Besides, this combined pretreatment allowed a high recovery of the cellulosic fraction from the biomass. Enzymatic saccharification was studied between steam exploded Cotton Stalk (SECS) and SECOH using different cellulase loadings. SECOH gave a maximum of 785.30 ± 8.28 mg/g reducing sugars with saccharification efficiency of 82.13 ± 0.72%. Subsequently, fermentation of SECOH hydrolysate containing sugars (68.20 ± 1.16 g/L) with Saccharomyces cerevisiae produced 23.17 ± 0.84 g/L ethanol with 0.44 g/g yield.
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Bioconversion of alkali delignified Cotton Stalk using two-stage dilute acid hydrolysis and fermentation of detoxified hydrolysate into ethanol
Industrial Crops and Products, 2016Co-Authors: Praveen Kumar Keshav, Naseeruddin Shaik, Sravanthi Koti, Venkateswar Rao LingaAbstract:Abstract Green biotechnology offers a promising approach to convert most of the solid agricultural wastes particularly lignocellulosic biomass into liquid biofuels. In this study, pretreatment of Cotton Stalk with sodium hydroxide (3% w/v; room temperature for 24 h) removed lignin (52.48 ± 1.17%) with minimum sugar loss (3.50 ± 0.09%). Subsequent two-stage dilute acid hydrolysis of alkali delignified Cotton Stalk released 29.40 ± 0.85 g/L sugars with 63.50 ± 1.06% holocellulose hydrolysis along with furfurals (1.32 ± 0.10 g/L) and phenolics (2.18 ± 0.15 g/L) in the hydrolysate. Detoxification of hydrolysate with overliming and adsorption with activated charcoal caused 59.12% and 78.44% reduction in total furfurals and phenolics, respectively. Batch fermentation of detoxified acid hydrolysate with monoculture and cocultures of Saccharomyces cerevisiae VS3 and Pichia stipitis NCIM3498 showed ethanol production of 6.28 ± 0.08 g/L, (yield, 0.39 g/g); 10.14 ± 0.19 g/L (yield, 0.45 g/g) and 11.64 ± 0.32 g/L (yield, 0.47 g/g), respectively.
Run-cang Sun - One of the best experts on this subject based on the ideXlab platform.
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efficient recovery and structural characterization of lignin from Cotton Stalk based on a biorefinery process using a γ valerolactone water system
RSC Advances, 2016Co-Authors: Jiakun Liu, Run-cang Sun, Xueming Zhang, Zhongya Yan, Bo WangAbstract:In order to understand the integrated reaction behavior for biomass pretreatment using the γ-valerolactone (GVL)/water system, the recovery and structural changes of the lignin components from Cotton Stalk obtained under different ratios of GVL to water were investigated. Structural elucidation of these lignin samples was performed by Fourier transform infrared spectroscopy (FT-IR), high-performance anion-exchange chromatography (HPAEC), gel permeation chromatography (GPC), 2D heteronuclear single quantum coherence spectroscopy nuclear magnetic resonance (2D HSQC NMR), and derivatization followed by reductive cleavage (DFRC). The results showed that the separated lignin fractions possessed higher yields and purities than milled wood lignin (MWL). From the results of molecular weight, DFRC and 2D NMR analysis, it was also found that the lignin component from Cotton Stalk was a G–S type unit analogous to hardwood, and remarkable degradation and repolymerization occurred on lignin in this acid system, which led to more condensed and lower molecular weight lignin than MWL. Particularly, under the condition of GVL/H2O 80/20, the cleavages of aryl-ether bonds dramatically happened, resulting in the least amount of β-O-4′ linkages. Considering the concept of biorefinery, the one-pot acid GVL/H2O system with 80/20 GVL/H2O could be an attractive method for the simple and efficient recovery of lignin and sugars simultaneously from agricultural wastes.
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separation and characterization of lignin obtained by catalytic hydrothermal pretreatment of Cotton Stalk
Industrial Crops and Products, 2015Co-Authors: Donghong Zhao, Run-cang Sun, Xueming Zhang, Jinhui PangAbstract:Abstract A catalytic method for the isolation of lignin in high purity from Cotton Stalk was presented in this study. Lignin fractions were obtained by the extraction of Cotton Stalk under catalytic hydrothermal conditions in the presence of metal chlorides including AlCl3, CrCl3, FeCl3 and ZnCl2 as catalysts. Structural elucidation of these lignin samples was investigated by high-performance anion-exchange chromatography (HPAEC), gel permeation chromatography (GPC), and 2D HSQC NMR spectroscopy. The results showed that the separated lignin fractions possessed higher purities than milled wood lignin (MWL). 2D NMR spectra demonstrated that guaiacyl (G) and syringyl (S) units were predominant in these lignin fractions, similar to the typical lignin types of hardwood. Moreover, the obtained lignin fractions consisted mainly of β-O-4′ aryl ether linkages, followed by resinol and phenylcoumaran structures. It was also found that the cleavages of β-O-4′ linkages occurred remarkably due to the presence of catalysts, and their decreasing severities were consistent with the acidity of the metal chlorides. In addition, the degradation was accompanied by a mild repolymerization during the catalytic hydrothermal pretreatment. In consideration of the relatively high yield and purity, isolation of lignin from raw materials by using catalytic hydrothermal pretreatment catalyzed by AlCl3 provided us a more effective approach for biomass pretreatment.
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isolation and structural characterization of lignin from Cotton Stalk treated in an ammonia hydrothermal system
International Journal of Molecular Sciences, 2012Co-Authors: Sumin Kang, Lingyan Meng, Xueming Zhang, Lingping Xiao, Run-cang SunAbstract:To investigate the potential for the utilization of Cotton Stalk, ammonia hydrothermal treatment was applied to fractionate the samples into aqueous ammonia-soluble and ammonia-insoluble portions. The ammonia-soluble portion was purified to yield lignin fractions. The lignin fractions obtained were characterized by wet chemistry (carbohydrate analysis) and spectroscopy methods (FT-IR, 13 C and 1 H- 13 C HSQC NMR spectroscopy) as well as gel permeation chromatography (GPC). The results showed that the Cotton Stalk lignin fractions were almost absent of neutral sugars (0.43%-1.29%) and had relatively low average molecular weights (1255-1746 g/mol). The lignin fractions belonged to typical G-S lignin, which was composed predominately of G-type units (59%) and noticeable amounts of S-type units (40%) together with a small amount of H-type units (~1%). Furthermore, the ammonia-extractable lignin fractions were mainly composed of β-O-4' inter-unit linkages (75.6%), and small quantities of β-β' (12.2%), together with lower amounts of β-5' carbon-carbon linkages (7.4%) and p-hydroxycinnamyl alcohol end groups.
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Comparative Characterization of Lignins Extracted from Cotton Stalk Based on Complete Dissolution in Different Systems
Industrial & Engineering Chemistry Research, 2012Co-Authors: Lingyan Meng, Sumin Kang, Xueming Zhang, Run-cang SunAbstract:A method for the isolation of lignin in high purity from Cotton Stalk is presented in this study. Lignin fractions were obtained by dissolution of ball-milled Cotton Stalk in lithium chloride/dimethylacetamide (LiCl/DMAc), tetrabutylammonium fluoride/dimethylsulfoxide (TBAF/DMSO), lithium chloride/N-methyl-2-pyrrolidone (LiCl/NMP), NaOH/urea/H2O, NaOH/thiourea/H2O, and 1-allyl-3-methylimidazolium chloride/dimethylsulfoxide ([Amim]Cl/DMSO) followed by precipitation in the course of which lignin and carbohydrate fractions were separated. Structural elucidation of the lignin fractions was investigated by sugar analysis, FT-IR, and 1D/2D NMR spectroscopy. The results showed that the separated lignin fractions possessed higher purities and molecular weights than MWL. 1D/2D NMR spectra demonstrated that guaiacyl (G) and syringyl (S) units were predominant in the lignin fractions, and a small amount of p-hydroxyphenyl (H) unit was also detected. Moreover, the separated lignin fractions consisted mainly of β-O-4′...
Ulku Yilmazer - One of the best experts on this subject based on the ideXlab platform.
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production and characterization of films from Cotton Stalk xylan
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Emel Iraz Goksu, Mehlika Karamanlioglu, Ufuk Bakir, Levent Yilmaz, Ulku YilmazerAbstract:Composite film production based on Cotton Stalk xylan was studied, and the mechanical and physical properties of the films formed were investigated. Xylan and lignin were separated from cellulose by alkali extraction and, then, lignin was removed using ethanol washing. Self-supporting continuous films could not be produced using pure Cotton Stalk xylan. However, film formation was achieved using 8-14% (w/w) xylan without complete removal of lignin during xylan isolation. Keeping about 1% lignin in xylan (w/w) was determined to be sufficient for film formation. Films were produced by casting the film-forming solutions, followed by solvent evaporation in a temperature (20 degrees C) and relative humidity (40%) controlled environment. The elastic modulus and hypothetical coating strength of the films obtained by using 8% xylan were significantly different from the ones containing 10-14% xylan. The water vapor transfer rates (WVTR) decreased with increasing xylan concentration, which made the films thicker. The glycerol addition as an additional plasticizer resulting in more stretchable films having higher WVTR and lower water solubility values. As a result, film production was successfully achieved from xylan, which was extracted from an agricultural waste (Cotton Stalk), and the film-forming effect of lignin on pure xylan has been demonstrated.
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production and characterization of films from Cotton Stalk xylan
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Emel Iraz Goksu, Mehlika Karamanlioglu, Ufuk Bakir, Levent Yilmaz, Ulku YilmazerAbstract:Composite film production based on Cotton Stalk xylan was studied, and the mechanical and physical properties of the films formed were investigated. Xylan and lignin were separated from cellulose by alkali extraction and, then, lignin was removed using ethanol washing. Self-supporting continuous films could not be produced using pure Cotton Stalk xylan. However, film formation was achieved using 8–14% (w/w) xylan without complete removal of lignin during xylan isolation. Keeping about 1% lignin in xylan (w/w) was determined to be sufficient for film formation. Films were produced by casting the film-forming solutions, followed by solvent evaporation in a temperature (20 °C) and relative humidity (40%) controlled environment. The elastic modulus and hypothetical coating strength of the films obtained by using 8% xylan were significantly different from the ones containing 10–14% xylan. The water vapor transfer rates (WVTR) decreased with increasing xylan concentration, which made the films thicker. The glyc...
