CARBON
·
2017
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IF 6.337
Jie Wang,Xiaming Zhang,Yulong Miao,Yaoyao Li,Xianfeng Xi,Xiqiang Zhong,Xueliang Pei,Liu He,Qing Huang
The influences of carbon nanotubes (CNTs) introduced in three different phases of carbon fiber/pyrolytic carbon/silicon carbide (Cf/PyC/SiC) composites on the microstructure and properties of the composites were investigated in this paper. The results showed with CNTs introduced at PyC-PyC interface, tensile strength and work of fracture (WOF) of a Cf/PyC/SiC composite had the largest increase, and significantly improved 54.9% and 130.3% respectively from those of the CNTs-free composite. Multiple interfaces (CF-PyC interface, CNT-PyC interface, PyC-PyC interface) failure and a great number of carbon fiber and carbon nanotube pull-outs were observed from tensile fracture morphology of the composite, which indicated weakening of PyC-PyC interface due to CNTs and accounted for the remarkable improvement in WOF of the composite. The increase of tensile strength of the composite was resulted from the reduction of residual stress of the composite.
研究领域:
材料科学
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复合材料
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机械工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2021
·
IF 4.089
Jie Hu,Zhengqing Kong,Ke Liu,Jinli Qin,Yuhong Tao,Lijuan Zhou,Yuan Yuan,Min Jiang,Yongxin Duan,Jianming Zhang
The surface functionalization of cellulose nanocrystals (CNCs) and the construction of strong interfacial adhesion between CNCs and the rubber matrix are effective ways to achieve high-performance rubber/CNCs nanocomposites. Herein, carboxylation of sulfonic CNCs (CNC–OSO3H) was conducted in an aqueous medium by using citric acid (CA) as the modifier. A large number of carboxyl groups were successfully grafted on the surface of CNC–OSO3H, and most of the sulfonic groups were removed, which endows the carboxylated CNC–OSO3H (abbreviated as CNC–CA) with higher chemical reactivity and thermal stability. Subsequently, carboxylated styrene-butadiene rubber (XSBR)/CNC–CA nanocomposites with a dual cross-linking network were prepared by using polyethylene glycol diglycidyl ether (PEGDE) as the cross-linking agent and CNC–CA as reinforcing fillers. Fourier transform infrared spectroscopic investigation found that in the obtained nanocomposites, the carboxyl groups on CNC–CA and XSBR formed hydrogen bonds (physical cross-linking) with each other, and the carboxyl groups formed covalent bonds with the epoxy group on PEGDE simultaneously. The coexistence of physical and chemical cross-linking improved the interface compatibility between CNC–CA and the XSBR matrix, accelerated the homogeneous dispersion of CNC–CA, and realized the cross-linking of the matrix itself. As expected, XSBR/CNC–CA nanocomposites with a dual cross-linking network showed a remarkable enhancement in tensile strength (up to 500%), modulus (up to 151%), and work of fracture (up to 348%). This work provides both a facile and green approach to obtain carboxylated CNCs and a convenient method for the preparation of high-performance rubber nanocomposites with dual cross-linking networks.
研究领域:
材料科学
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高分子化学
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纳米技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Yehong Cheng,Yang Lyu,Shanbao Zhou,Wenbo Han
Although axially aligned fibrous monolithic ceramics have superior mechanical properties in ceramic fiber axial direction, the obvious anisotropy in physical and chemical properties of fibrous monolithic ceramics predetermine the significant on-axis and off-axis discrepancy. The existing ZrB 2 -based fibrous monolithic ceramics were all arranged by axially aligned ceramic fibers. Non-axially aligned ZrB 2 -SiC/ZrB 2 -SiC-graphene short fibrous monolithic ceramics with isotropic in-plane properties were fabricated by hot pressing of disorderly-arranged short ZrB 2 -SiC/ZrB 2 -SiC-graphene fibers to overcome in-plane anisotropy of the ZrB 2 -based fibrous monolithic ceramics. ZrB 2 -SiC/ZrB 2 -SiC-graphene short fibrous monolithic ceramics have remarkable increase in fracture toughness, critical crack size and work of fracture compared with ZrB 2 -SiC ceramics. The toughening mechanism of ZrB 2 -SiC/ZrB 2 -SiC-graphene short fibrous monolithic ceramics include macroscopic toughening of crack deflection, crack branching, interface friction and ZrB 2 -SiC cell extraction, and microscopic toughening of graphene bridging and pull-out.
研究领域:
材料科学
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陶瓷
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复合材料
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力学性能
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2023
·
IF 5.5
Ning Wang,Zikang Li,Ge Zhu,Zechuan Yu,Renyuan Qin,Ji Zhou,Ning Lin
How do the degrees of surface modification on nanoparticles affect their enhancement to the mechanical performance of composites? This issue is generally overlooked with a consensus that surface modification can promote the compatibility between nanoparticles and polymeric matrix, which therefore advances mechanical performances of obtained composites. In this study, we designed a composite system of castor oil (CO)-based polyurethane (PU) as the matrix enhanced by cellulose nanocrystals (CNCs) with changing surface modifications of low, moderate, and high grafting of the CO chains as nanofillers. The compatibility between modified CNCs and PU was quantified by the Hansen solubility parameters, with the gradual decrease of Ra values from 14.1 to 6.1. The interfacial compatibility between nanofillers and matrix directly determined the dispersion and microstructures of composite systems and further influenced mechanical performances of materials, exhibiting the improvement on Young’s modulus, tensile strength, work of fracture, and storage modulus for the modified CNC-enhanced composites. In comparison with theoretical calculations by the classic percolating network model and Halpin–Kardos model, the effects of mechanical enhancement for PU-based composites by CNCs were simulated, revealing stronger interfacial adhesion from the entanglement of grafted CO chains and PU chains and therefore a tighter binding between nanofillers and matrix in composites.
研究领域:
材料科学
·
高分子科学
·
纳米技术
·
机械工程
✓ 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）