Coatings
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2022
·Vol. 13
·期 1
·3
·
IF 3.236
Chen Gong,Jianping Ni,Shujie Fan,Yu Zhang,Bin Yang,Zhenhua Su
Lyocell fiber has emerged as a new generation of green fiber due to its preparation process and unique properties in comparison with viscose fiber. The raw material for the preparation of Lyocell fiber has a great impact on the quality of the finished product. However, unlike viscose-grade dissolving pulp, there is no evaluation system for Lyocell-grade dissolving pulp, making it difficult to assess the quality of the raw material. This study examined the approach to upgrade the paper-grade pulp to dissolving pulp for the preparation of the raw material for Lyocell fiber. Under the sequence of caustic extraction, acid treatment, and enzymatic treatment, the pulp was prepared with competitive properties compared to the commercial Lyocell-grade dissolving pulp. The assessment of prepared pulp was also accomplished by characterizing the pulp properties, the dissolution properties, and the spinnability and stability of Lyocell solution using the prepared sample. In addition, the dissolution mechanism and influencing factors of pulp in the system were elucidated, providing a theoretical basis for upgrading paper-grade pulp to dissolving pulp for Lyocell fiber production.Keywords:dissolving pulp;Lyocell fiber;assessment;dissolution properties;spinnability
研究领域:
材料科学
·
纺织工程
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Jixiao Hao,Shuai Yan,Hua Yuan,Cong Du,Yeqiang Tan
Facing the severe problem of microplastic pollution, there is an urgent need to develop biodegradable fibers to replace the petrochemical fibers. Sodium alginate , a biomass polysaccharide , has gained widespread attentions recently for the fiber manufacture. However, the limited mechanical strength of alginate fibers restricts their usages as load-bearing fabrics and reinforcement fibers . Here, we develop a novel strategy to prepare alginate multifilaments using pre-crosslinked sodium alginate solutions. The increase in the pre-crosslinking ratio effectively hinders the disentanglement of sodium alginate chains at high stretches, causing an increase in the shear viscosity of the solution ascertained from the capillarity-driven thinning process from 4.5 Pa·s to 9.9 Pa·s and facilitating the high alignment and orientation of sodium alginate chains. The resultant fibers possess a breaking strength of 474 MPa, elongation at break of 16 %, Young's modulus of 14.4 GPa, and toughness of 51.8 MJ/m 3 , exceeding most biomass fibers without reinforcement additives. The high orientation degree of 0.865 and high spinnability of alginate multifilaments enable their applications in multi-channel encryption fabrics that exhibit distinct information under various optical conditions. This rheological regulation of spinning solutions provides a facile yet effective strategy to enhance the mechanical performance and broaden application scenarios of alginate fibers.
研究领域:
材料科学
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环境科学
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生物工程
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产品关联
DOI
PubMed
高影响因子
Marine Drugs
·
2024
·Vol. 22
·期 10
·443
·
IF 4.9
Hengjie Su,Xiaoqi Chen,Linna Mao,Ting Li
The electrospinning of pure chitosan nanofibers is highly sensitive to environmental humidity, which limits their production consistency and applicability. This study investigates the addition of sodium chloride (NaCl) to chitosan solutions to enhance spinnability and mitigate the effigurefects of low humidity. NaCl was incorporated into the electrospun chitosan solution, leading to increased conductivity and decreased viscosity. These modifications improved the electrospinning process. Comparative analyses between chitosan membranes (CM) and sodium-chloride-added chitosan membranes (SCM) revealed no significant differences in chemical structure, mechanical strength, or in vitro cell proliferation. This indicates that the addition of 1% (w/v) NaCl does not adversely affect the fundamental properties of the chitosan membranes. The findings demonstrate that NaCl addition is a viable strategy for producing electrospun chitosan nanofibers in low-humidity environments, maintaining their physicochemical properties while enhancing spinnability.
研究领域:
材料科学
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生物医学工程
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高分子科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2024
·
IF 5.8
Hongfeng Gao,Xiongchao Lin,Yukun Zhang,Caihong Wang,Zhe Sheng,Hongcun Bai,Yonggang Wang
This study developed a novel method for synthesis highly spinnable pitch through thermal polymerization of halogenated polycyclic aromatic hydrocarbons (PAH-X) and anthracene oil (AO). The characteristics, average molecular model, and polymerization mechanism of the as-prepared pitches were systematically elucidated. Results show that the thermal cleavage of C-X bonds of the PAHs-X could generate large number of free radicals that greatly facilitate the cross-linking reaction of the active fragments. Namely, the formation of benzyl radicals with high reactivity of the raw materials made it possible to synthesize pitches at lower temperature. The softening point of the as-prepared pitches showed a decreasing trend with increasing of AO proportion due to the abundant carbon content and lower reactivity of AO. Higher temperature could elevate the polymerization activity of aromatic fragments, thus significantly promoted the formation of macromolecular aromatic structures to obtain the spinnable pitch with suitable softening point. The average models validated by calculating the NMR spectra was successfully constructed to demonstrate the condensation degree, which was found be conducive to probe the spinnability of the pitches. Further, the average molecular models could well describe the correlation of the molecular structure, spinnability of pitches, as well as the mechanical properties of carbon fiber.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 135
·期 14
·46072
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IF 1.86
Chengdong Xiong,Xianglong Li,Teng Hou,Bin Yang
Melamine microfibers were first prepared by centrifugal spinning. The stability and spinnability of a melamine–formaldehyde (MF) resin solution were improved as expected by adding various modifier combinations. Considering the storage stability of solutions characterized by visual inspection, turbidity tests, and viscosity measurements and combined with the fiber morphology, the optimal modifier combination was obtained. The spun fibers manifested a good morphology and thermal stability as measured by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Moreover, microfibers prepared by three spinning methods (centrifugal spinning, electrospinning, and centrifugal electrostatic spinning) were compared to choose the suitable spinning method for different fields in the future. This work provides systematic and scientific guidance on the synthesis of MF resin solutions and rapid mass production of melamine microfibers and also demonstrates that centrifugal spinning of melamine microfiber is a promising candidate for flame retardance and CO 2 adsorption at elevated temperature. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46072.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2023
·
IF 5.9
Yanlu Sun,Zhengqi Wang,Dequn Wu,Xueli Wang,Jianyong Yu,Ruchao Yuan,Faxue Li
The absence of inherently flame-retardant polyamide 6 (FR-PA6) with enhanced anti-dripping and melt spinnability has significantly limited its further application in textiles. In this work, a binary reactive flame retardant composed of commercial 9,10-dihydro-10-[2,3- di ( hydroxycarbonyl ) propyl ]-10-phosphaphenanthrene-10-oxide (DDP) and synthesized polydiphenylsiloxane (PDPS) was employed to fabricate FR-PA6 through a facile synthetic route. The prepared FR-PA6 containing 5 wt% DDP and 5 wt% PDPS (FR-PA6-5-5) exhibited a UL94 V-0 rating with no melt-droplets during combustion, a 31.0% reduction in heat release rate and a 18.8% decrease in total heat release compared to pure PA6 in cone calorimetric tests. The improved fire safety of FR-PA6-5-5 was contributed to the gas-phase quenching and dilution effect and the condensed-phase barrier effect, which was enhanced by the synergistic charring effect achieved through the formation of P(= O )-O-Si. Additionally, FR-PA6-5-5 exhibited excellent melt spinnability as demonstrated by the successful preparation of filaments with a tensile strength of approximately 2.27 cN/dtex.
研究领域:
材料科学
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纺织工程
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Chunlan Li,Wensheng Liu,Tao Luo,Ming Cheng,Qiang Liu,Juan Wang,Shuwei Yao,Yunzhu Ma
The structure and spinnability of sol are essential for obtaining high-performance continuous alumina-based fibres. Herein, the surface electrostatic potential analysis and conventional experimental methods (X-ray diffraction, Fourier-transform infrared spectroscopy, 27 Al nuclear magnetic resonance solution spectra and rheological methods) were combined to investigate and discuss the relationship between the structure and spinnability of aluminium carboxylate sols with different formic-acid-to-acetic-acid molar ratios. The results showed that the aluminium carboxylate sol structure changed with the formic-acid-to-acetic-acid molar ratio and greatly affected the sol's spinnability. The tetramer (AlO6 oligomer) products comprising two effective active carboxylate groups in the sol increased with the formic acid content, which helped form linear long-chain polymers. However, excess formic acid content led to a large increase of AlO6 monomer products that were unable to form linear long-chain polymers, which decreased the sol's spinnability. When the formic-acid-to-acetic-acid molar ratio was 1.15:0.85, the sol containing more AlO6 oligomer products had the best spinnability. Furthermore, α-Al 2 O 3 ceramic fibres with good morphology, small grains and uniform diameter distribution were obtained after calcination at 1200 °C.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2022
·
IF 6.364
Qiang Gao,Cheng Han,Xiaozhou Wang,Yingde Wang
Polymeric precursors with refractory metal in the main chain while still possess meltable/soluble characteristics are highly desired for ultra-high temperature ceramics (UHTCs). Herein, we proposed a stepwise synthesis of polyzirconosilane (PZCS) with Zr-C-Si-N polymeric chain. The reaction mechanism was discussed based on the frontier molecular orbital theory and atom transfer radical polymerization , which was initiated and propagated by a low oxidation state active specie of Cp 2 Zr(II). The PZCS precursor has excellent soluble and meltable properties with a softening point of 80.8 ~ 89.2 o C, which could be spun into green fibers by melt spinning technique. The ceramization process of PZCS was studied, and the resulted SiZrNC multinary ceramics were composed of ZrC/SiC nanocrystals embedded by graphitized carbon phase. The excellent mouldable properties, oxygen-free compositions and high Zr content of PZCS make it an ideal precursor for the preparation of UHTCs matrixes and fibers.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Kejian Yang,Qi Guo,Yanlin Liu,Jinping Ni,Zhaobin Tang,Xudong Chen
The long-ignored discoloration behavior of polyamide during polymerization has a significant impact on its properties and applications. Here, we innovatively analyzed the discoloration behavior of pentamethylenediamine-derived bio-based copolyamide (PA5T/56) and proposed a possible discoloration mechanism. Pentamethylenediamine performed cyclization reactions at high temperature to generate piperidine, which was then combined with terephthalic acid to form dipiperidine terephthalate. After being oxidized, dipiperidine terephthalate was converted to terephthalic acid bis(2-carbonyl substituted piperidine), which was believed to be responsible for the discoloration of polyamide during polymerization. Moreover, it was demonstrated that the discoloration behavior led to poor spinnability and dyeability of ultrafine polyamide fibers. This work will help to optimize the polymerization process of pentamethylenediamine-derived polyamide and expand its applications in high-performance fibers and other fields.
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
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 11
·5509-5520
·
IF 3.784
Yiang Du,Bing Wang,Wei Li,Quzhi Song,Changwei Shao,Cheng Han,Yingde Wang
Synthesis of spinnable precursors with high ceramic yield is a crucial issue in BN fibers manufacturing by polymer-derived ceramics (PDCs) route. Spinnability and high ceramic yield are the basis of precursor processability, formability, and mechanical properties. Herein, based on DFT simulation, we designed and synthesized a novel polymer precursor poly[2-propylamino-4,6-bis(methylamino) borazine-co-tri(methylamino) borazine] (PPMAB) via a facile one-pot copolymerization strategy. The random copolymerization model of condensations was obtained through DFT calculation. The molecular chain structure, molecular weight, and molecular weight distribution were optimized by adjusting the synthesis conditions. The precursor PPMAB-1:1 with a high ceramic yield of 62.43% and concentrated molecular weight distribution (PDI < 1.3) was obtained. Rheological performance research revealed the excellent and stable spinnability of PPMAB-1:1 by the tunable viscosity and low flow activation energy (23.61 kJ/mol). As a demonstration of spinnability, continuous BN fiber with a fine diameter (>10 km, 7.60 ± 1.13 μm, and 1.6 GPa) was obtained after melt spinning. The present work effectively improved the ceramic yield and spinnability of polyborazine precursors. Simultaneously, it can be used extensively as a universal method to prepare multifunctional copolymers with precise structure control.
研究领域:
材料科学
·
聚合物化学
·
陶瓷工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）