ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2017
·Vol. 24
·期 21
·17711-17718
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IF 2.741
Ma Bomou,Sun Qisong,Yang Jing,Wizi Jakpa,Hou Xiuliang,Yang Yiqi
Chicken feather, a potential source of keratin, is often disposed as waste material. Although some methods, i.e., hydrolysis, reduction, and oxidation, have been developed to isolate keratin for composites, it has been limited due to the rising environmental concerns. In this work, a green solvent N -methylmorpholine N -oxide (NMMO) was used to extract keratin from chicken feather waste. Eighty-nine percent of keratin was extracted using 75% NMMO solution. However, the result from size exclusion HPLC showed that most of the keratin degraded into polypeptide with molecular weight of 2189 and only 25.3% regenerated keratin was obtained with molecular weight of 14,485. Analysis of amino acid composition showed a severe damage to the disulfide bonds in keratin during the extraction procedure. Oxidization had an important effect on the reconstitution of the disulfide bonds, which formed a stable three-dimensional net structure in the regenerated keratins. Besides, Raman spectra, NMR, FT-IR, XRD, and TGA were used to characterize the properties of regenerated keratin and raw chicken feather. In the end, a possible mechanism was proposed based on the results.
研究领域:
生物化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CELLULOSE
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2025
·
IF 4.8
Gunawan Ivana,Zhang Yue,Wang Huijie,Kou Mengtian,Wang Chao,Zhang Yumei
Pulp pre-treatment acts as a preliminary treatment in the lyocell process, allowing aqueous NMMO solvent molecules to penetrate the wood fiber structure. The present paper first determines cellulose’s pre-swelling, swelling, and dissolution phenomena in NMMO aqueous solutions of different concentrations and temperatures. It was found that instead of “ pre-swelling ” and “ dissolution ”, the “ swelling ” action during pre-treatment develops the most suitable interaction between wood pulp fiber and solvent. Higher concentrations of NMMO aqueous solutions (70–80%) do not contain enough water and that limits the uniform wetting of the pulp, while a lower NMMO concentration (50%) is not able to fully establish the hydrogen bonding interaction between cellulose and NMMO. The pre-treatment of cellulose pulp using 60% NMMO aqueous solution at 65 °C can ensure that NMMO itself does not degrade and provides sufficient solvent diffusivity for pulp based on the swelling effect. This significantly reduces heterogeneous microstructure aggregation and effectively promotes subsequent dissolution processes. The dissolved cellulose has more uniformity at the molecular level, showing lower dope relaxation time and gel temperature, which offers better alternatives for stable, high-viscosity lyocell spinning, and constructs stronger fiber compared to that of un-treated pulp.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2021
·
IF 5.645
Hongmei Yuan,Jianfei Wu,Dong Wang,Liulian Huang,Lihui Chen,Shan Lin
Regenerated cellulose (RC) films have numerous separation and purification applications. However, the mechanical properties of RC films are poor. Because of their very similar chemical structures and excellent compatibility, chitosan (CS) particles were chosen to reinforce bamboo-derived dissolving pulp (BP)-based films. BP/CS blend solutions were obtained by mixing BP and CS particles at different weight percentages into N-methyl-morpholine-N-oxide (NMMO) solvent. The BP/CS composite films prepared by the traditional phase transformation method formed a physically cross-linked network with high packing density for the water evaporation after air-drying. Due to the strong hydrogen bonding between CS and BP revealed by rheological properties and Fourier transform infrared (FTIR) data, the CS particles dispersed uniformly in the matrix, and the compatibility of the reinforcement with the matrix was excellent, which was further confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–vis transmittance data. As the weight percentage of CS increased from 9.09 wt% to 14.24 wt%, the crystallinity of cellulose II increased from 32.20%–38.59%, and the tensile strength of the BP/CS composite films increased from 662.20 MPa to 865.53 MPa, respectively. These results indicate that the tensile strength of the BP/CS composite films was increased by nearly 250.83 %–358.56 % compared with that of the regenerated BP film (188.75 MPa). Moreover, the elongation at break was increased by 51.16 %-41.63 %. These findings provide a new way to prepare ultra-high-strength RC composite films.
研究领域:
材料科学
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化学工程
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高分子科学
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产品关联
DOI
高影响因子
CELLULOSE
·
2025
·
IF 4.8
Guo Yuqian,Cheng Yun,Hou Leilei,Chen Linghua,Zhang Jiaolong,Zhao Yumeng,Li Haiming,Zhang Hongjie
Considering the environmental requirements and economic sustainable development, it is crucial to adopt an environmentally friendly and effective pre-treatment to improve the dissolution efficiency of cellulose in aqueous N-methyl-morpholine-N-oxide (NMMO) solution by disrupting the intra- and inter-molecular hydrogen bonds of cellulose for the development of the lyocell fiber industry. Herein, a facile strategy of synergetic ultrasound-swollen treatment was developed to shorten the swelling and dissolution time to make a homogeneous cellulose solution. The novelty of this work lies in that the synergetic ultrasound-swollen treatment could effectively disrupt the molecular chains of cellulose, increase the pore volume and specific surface area, and accelerate the dissolution of cellulose in aqueous NMMO solution. The substantial decrease (55.76%) of number-average molecular weight implied the cleavage of molecular chains. The remarkable increase of specific surface area (about 5 times) and short dissolution time proved the effective synergetic effect of ultrasonic cavitation and swelling of NMMO solution. Therefore, the synergetic ultrasound-swollen treatment not only accelerated the diffusion of the NMMO solution into the crystalline regions of cellulose to disrupt molecular chains, but also enlarged the specific surface area and improved the dissolution efficiency. Graphical abstract
研究领域:
高分子科学
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化学工程
·
材料科学
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绿色化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）