POLYMERS FOR ADVANCED TECHNOLOGIES
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2022
·Vol. 33
·期 7
·2265-2275
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IF 3.348
Xuan Fei,Yingkang Zhu,Jinggang Wang,Zhen Jia,Xiaoqing Liu
To enhance the crystallization of poly(butylene 2,5-furandicarboxylate) (PBF) thus substitute its petroleum-based analogue poly(butylene terephthalate) (PBT), a series of high molecular weight poly(butylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate) (PBCF) copolyesters with low contents (0–19 mol%) of 1,4-butanediol (BDO) are synthesized from 2,5-furandicarboxylic acid (FDCA), 1,4-cyclohexanedimethylene (CHDM) and BDO. Their chemical structures and compositions are confirmed by nuclear magnetic resonance ( 1 H NMR and 13 C NMR). Their number average molecular weights are from 20,500 to 36,100 g/mol with the polydispersity index ( Ð ) of 1.67–1.99. The thermal stability and crystallization behaviors are investigated by thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC). Results show that PBCFs demonstrate comparable crystallization rate to PBT as the crystallization half time is from 18 to 29 s and the melting enthalpy is 34.1–41.4 J/g as well as the higher melting temperature of 238–263°C than 225°C for PBT. In addition, PBCFs exhibit excellent mechanical properties of tensile modulus between 1220 and 1510 MPa. These investigations suggest that a moderate amount CF unit can improve the melting temperature and enhance the originally weak crystallizability of furan-based polyesters. Generally, PBCFs can be the engineering plastic with satisfied thermal and mechanical performance.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
JOURNAL OF RARE EARTHS
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2024
·
IF 5.2
Ke Xue,Changkun Cai,Manyi Xie,Shuting Li,Shengli An,Hong Yang
PrBaFe 2 O 5+ δ (PBF) is one of the promising cathode materials for intermediate-temperature solid oxide fuel cell (IT-SOFC) technology. However, as the operating temperature decreases, the electrochemical performance of this material deteriorates rapidly. To counter this, various doping strategies have been tested and reported in order to improve the electrochemical properties of this material at intermediate-temperatures. In this study, Mg-doping to partially substitute Fe of PBF was investigated. PrBaFe 2– x Mg x O 5+ δ (PBFMg x , x =0.1, 0.15, 0.2, 0.3) materials were successfully synthesized, and their electrochemical performance as IT-SOFC cathode was evaluated. It is shown that Mg-doping enhances the conductivity of PBF between 650–800 °C, impacts little on the area-specific resistance of oxygen reduction reaction at and above 700 °C, and, most significantly, improves the power density of the Ni-SDC/SDC/PBFMg 0.15 single cell by 52% compared to the un-doped PBF. This enhanced electrochemical performance is attributed to the improvement in PBF conductivity by Mg-doping.
研究领域:
材料科学
·
能源科学
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DOI
高影响因子
Materials Today Communications
·
2026
·
IF 4.9
Shuai Zhao,Dayang Cai,Jinxing Sun,Jingpeng Luo,Jiaming Bai
ZnO@CF hybrids were prepared via wet-chemical deposition followed by thermal treatment. • ZnO surface modification increased CF surface roughness and favored interfacial interlocking. • ZnO@CF/PEEK exhibited higher complex viscosity and storage modulus than CF/PEEK. • 10-ZnO@CF/PEEK achieved a UTS of 125.4 MPa, 8.1% higher than 10-CF/PEEK. Powder bed fusion (PBF) of carbon fiber-reinforced polyether ether ketone (CF/PEEK) composites is often constrained by weak fiber–matrix interfacial bonding. Here, ZnO nanoparticles were deposited onto milled CFs via an in situ wet-chemical route to enhance mechanical interlocking. ZnO surface modification increased CF surface roughness (8.2 to 11.3 nm) and specific surface area (by 57.2%). While slightly increasing melt viscosity, ZnO@CF significantly improved composite mechanical properties: 10-ZnO@CF/PEEK achieved an ultimate tensile strength of 125.4 MPa (8.1% higher than 10-CF/PEEK), and 15-ZnO@CF/PEEK reached a Young’s modulus of 8.80 GPa and a flexural strength of 181.9 MPa. Fracture surface analysis confirmed enhanced matrix adhesion on pulled-out fibers, demonstrating effective interfacial stress transfer driven by nanoscale topographical features. This work provides an efficient strategy for interfacial regulation in additively manufactured PEEK composites. Download: Download high-res image (266KB) Download: Download full-size image
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高影响因子
Coatings
·
2026
·Vol. 16
·期 5
·543
·
IF 3.4
Wei Zhang,Baozhen Yang,En Zhu,Feibiao Yu
A three-factor, four-level orthogonal design was employed to optimize the overall forming quality of powder bed fusion with a laser beam (PBF-LB)-fabricated TC4 alloy containing 0.3 wt.% YH2. Sixteen process-parameter combinations were established, and two specimens were fabricated for each combination. Laser power, scanning speed, and hatch spacing were selected as the investigated variables. Relative density, surface roughness, and Vickers hardness were evaluated using the entropy weight method combined with the weighted-sum method. On this basis, the microstructure of the specimens produced under the optimal process parameters was systematically characterized. The results showed that the influence of the investigated factors on overall forming quality followed the order: hatch spacing > laser power > scanning speed. The optimal process parameters were a laser power of 200 W, a scanning speed of 1100 mm/s, and a hatch spacing of 0.10 mm, under which the specimens exhibited superior overall forming quality. The addition of 0.3 wt.% YH2did not significantly alter the dominant phase constitution of the alloy, but promoted α′ martensite refinement and weakened the texture through the in situ formation of Y2O3nano-oxide particles.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Xing Wang,Siying Xiang,Zhengze Wang,Minzhe Peng,Guangxian Li,Yajiang Huang
Polypropylene (PP) copolymer powder usually displays low laser absorbance and inferior laser powder bed fusion (PBF-LB) additive manufacturing processability. Herein, hydrophobic silica nanoparticles (NPs), which are generally used as flow aids to coat powders, were in-particle compounded into PP particles and were found to cause an unexpected upgrade in the PBF-LB processability of PP powder. PP powders with minute amounts (∼0.3 wt %) of in-particle compounded silica NPs exhibited a largely reduced zero-shear viscosity (∼45%), a broadened sintering window, and stronger laser heating behavior. As a result, the PP powder was fabricated successfully into parts with fewer defects, better shape accuracy, and higher mechanical performance. The new phenomena observed were interpreted in terms of better fusion due to abnormal rheological behavior and improved laser absorbance in the presence of trace silica NPs. Therefore, this study unleashed the multiplicity and enormous potential of silica NPs in developing new feedstocks for PBF-LB.
研究领域:
材料科学
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增材制造
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聚合物工程
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Xiaodong Cai,Yexin Yang,Huatong Yu,Danhua Jiao,Liangliang Xu,Daohai Zhang
Designing and synthesizing bio-based furandicarboxylic acid (FDCA)-based copolyesters with high thermal, mechanical, and modest hydrolytic properties present a significant challenge. In this study, poly(butylene furandicarboxylate) (PBF) was modified with the bio-based cyclic ether diol 2,5-tetrahydrofurandimethanol (THFDM). The resulting sustainable poly(butylene furandicarboxylate-co-hydroxymethyl tetrahydrofuran furandicarboxylate) (PBThFs) copolyesters displayed random microstructures with molecular weights (Mw) ranging from 20.8 to 62.6 × 103 g/mol. PBThFs transitioned from a partially crystalline to a fully amorphous state while maintaining thermal stability above 367 °C. The tensile strength and modulus of PBF were 49 and 1479 MPa, respectively, while PBThF15 (with a feed molar ratio of THFDM units at 15 mol %) showed improved values of 77 and 1855 MPa. Adding THFDM units significantly increased the glass transition temperature from 39.9 to 74.7 °C. The presence of ether linkages in THFDM modified the hydrolytic degradation of PBThF copolyesters compared to pure PBF. The hydrolysis mechanisms were clarified using Fukui function analysis and DFT calculations, indicating the increased susceptibility of PBThFs to hydrolysis. This study demonstrates the feasibility of synthesizing high-performance FDCA-based copolyesters, facilitating a broad spectrum of applications.
研究领域:
材料科学
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化学工程
·
环境科学
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DOI
高影响因子
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