碳纤维增强木质素基酚醛树脂复合材料的制备及其性能

采用碱催化酚化的方式增加木质素反应活性以替代苯酚,用于制备酚醛树脂及碳纤维增强木质素基酚醛树脂复合材料,探讨了碱催化酚化工艺条件对木质素结构的影响,表征了不同取代比的木质素基酚醛树脂的结构,以及碳纤维增强木质素基酚醛树脂复合材料的形貌和力学性能。结果表明：经碱催化酚化的木质素反应活性明显增加,最佳工艺条件为温度90℃,时间90 min,碱用量4%(w);木质素基酚醛树脂与传统酚醛树脂结构相似,当木质素替代率为30%(w)时,可获得弯曲性能和层间剪切强度高的碳纤维增强木质素基酚醛树脂复合材料。     

木质素基燃料电池双极板的制备及性能研究

为了充分利用木质素,扩大其在复合材料的应用范围,采用木质素、苯酚和甲醛合成了木质素基酚醛树脂。以天然石墨和碳纤维做导电填料,采用模压工艺制备燃料电池用双极板材料。对复合材料的密度、弯曲性能、动态力学性能和电导率进行表征分析。结果表明,当天然石墨逐步被碳纤维取代后,木质素基复合材料的密度随着碳纤维含量的增加而逐渐下降;弯曲强度则一直增加,但是弯曲模量在碳纤维达到30%时达到最大值,之后开始下降。动态力学性能实验表明,材料的储能模量和玻璃化转变温度随着碳纤含量增加而增加,并在30%碳纤维时达到最高值。复合材料的电导率随着碳纤维含量增加而增加,最大达到500 S/cm,之后复合材料的电导率开始下降。研究结果证明,含有30%碳纤维和30%天然石墨的木质素基复合材料具有较好的综合性能:密度为1.16 g/cm~3,弯曲强度和弯曲模量分别为52.7 MPa和10.7 GPa,电导率500 S/cm。     

木质素基碳纤维复合材料在储能元件中的应用研究进展

基于木质素天然高分子成本低、可再生性、来源丰富、制备工艺简单以及结构可控等优势，将其制备成碳纤维并应用于超级电容器、可充电电池等储能元件，进一步发挥其充放电速度快、能量密度高和循环寿命长等优异的性能，已得到证实及应用。本文系统综述了近年来利用纺丝方法制备的木质素基碳纤维的过程工艺与纤维性能，并基于木质素基碳纤维在结构设计上的多样性，重点总结了不同木质素基碳纤维用作超级电容器和可充电电池电极材料所表现出的差异化电化学性能。此外，对木质素基碳纤维复合材料的发展前景和面临的挑战进行了展望，为木质素基碳纤维复合材料的下一步研究和开发提供思路。     

熔喷法制备木质素基碳纤维毡研究

为实现熔喷法制备木质素基碳纤维毡,先对木质素原料进行酚化改性,然后利用熔喷技术制备木质素基纤维毡;再进一步固化、预氧化和碳化得到木质素基碳纤维毡。采用粘度、熔点、热重和元素分析对木质素熔喷法制备碳纤维毡的工艺参数进行表征,并获得最佳熔喷、固化、预氧化和碳化工艺条件。     

一种木质素基纳米碳纤维及其制备方法

本发明提供了一种原料来源广泛、生产过程简单快速的木质素基纳米碳纤维,其以木质素和合成高分子为原料制备而成,直径为50－300nm,长度为1～20gm。本发明的木质素基纳米碳纤维的制备方法包括步骤：①将木质素与合成高分子一定比例共混、切片,并将切片在真空中干燥;     

低成本碳纤维复合材料在乘用车上的应用

碳纤维增强复合材料(CFRP)可以减轻乘用车体质量,改善燃油效率,减少CO2的排放,但碳纤维高昂的成本制约了它的广泛应用。简介了低成本碳纤维(LCCF)的研究与开发动向以及木质素基和聚烯烃基碳纤维技术快速进入商业化的的态势。     

瑞典研发100%木质素基碳纤维复合材料产品

<正>瑞典Innvetia科研所和Swerea SICOMP公司共同宣布,双方首次在世界范围利用木质素基-碳纤维,成功生产出碳纤维复合材料产品。这种碳纤维的生产原料采用100%天然软木木质素。尽管生产限定在实验室规模,但是工业规模量产才是双方最终的目标。研究人员相信,木质基-碳纤维复合材料可以在轻量化汽车领域实现大规模应用。     

碳纤维及其在复合材料方面的应用

本文首先叙述了碳纤维生产技术的进展,结构形态以及碳纤维在力学、物理、化学方面的性能。接着介绍了几种碳纤维增强的复合材料,着重阐述了碳纤维增强树脂基复合材料中基体的选择、特点和碳纤维含量对复合材料力学性能的影响。     

木质素基碳纤维的研制情况

综述了近几年木质素基碳纤维的研制情况,并就其性能作了介绍。     

木质素酚醛树脂碳纤维的制备及表征

用不同比例的木质素与甲醛、苯酚合成酚醛树脂,并进一步制备成碳纤维。应用热失重和元素分析研究了木质素酚醛树脂的碳化过程,结果表明,木质素的加入提高了树脂的热性能,降低了树脂的热降解程度。应用扫描电镜研究了木质素酚醛树脂碳纤维的微观结构,研究发现木质素含量的不同对碳纤维内部的微孔孔径具有可控作用。     

Thermal treatment of pyrolytic lignin and polyethylene terephthalate toward carbon fiber production

In this work, pyrolytic lignin (PL) was thermally co-treated with polyethylene terephthalate (PET) to produce carbon fiber precursor. The produced PL-PET precursors were thoroughly characterized and analyzed, and then being processed into carbon fiber. It was found that a novel precursor, rather than their physical blending, was formed by the thermal co-treatment, indicating there were strong interactions between PL and PET. The novel PL-PET precursors had enhanced thermal properties and rheological characteristics, therefore are more suitable for processing into better carbon fibers based on melt-spinning method. In this study, the precursor fibers derived from the co-treatment of PL and 5% PET were also stretched under tension during stabilization step to reduce the fiber diameter and improve molecular orientation. The resulting carbon fibers with an average diameter of 12.6 μm had the tensile strength of up to 1220 MPa. This work demonstrated that PET could be used to improve the processability and quality of lignin-based carbon fiber when it is chemically bonded with lignin-based precursor. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48843.     

A new modification method of exploded lignin for the preparation of a carbon fiber precursor

A lignin-pitch for carbon fiber was prepared in a high yield from exploded lignin on phenolysis followed by heat treatment under a vacuum. The lignin-pitch had an excellent spinnability in the melt state to form a fine filament. The green fibers were easily made infusible when heated in air at a relatively high heating rate (15-60°C/h). The lignin-based carbon fiber was produced in 43.7% of yield based on a starting material. The tensile strength was more than 400 MPa, indicating that the lignin-based carbon fiber is classified into a general purpose grade. © 1993 John Wiley & Sons, Inc.     

炭纤维增强聚己二酰己二胺力学性能的研究

介绍了炭纤维增强聚己二酰己二胺（ＣＦＲＰＡ６６）的力学性能,研究了炭纤维的长度分布对复合材料力学性能的影响,用ＭＭ２００磨损试验机测试了尼龙的磨损性能。试验结果表明,炭纤维增强尼龙６６及聚癸二酰己二胺（ＣＦＲＰＡ６１０）的力学性质显著提高,其中ＣＦＲＰＡ６６的力学性能提高更为显著;合适的螺杆组合可以使炭纤维在树脂中的长纤维比例增大,增强效果较好;ＣＦＲＰＡ６６的耐磨性提高,摩擦系数下降     

Use of organosolv lignin in phenol-formaldehyde resins for particleboard production: II. Particleboard production and properties

The objective of this work was to demonstrate the utility of lignin-based resins designed for application as an adhesive in the production of particleboard. Bond qualities of lignin-phenol-formaldehyde resins, phenolated-lignin-formaldehyde resins and commercial phenol-formaldehyde (PF-com) resin were assessed by using an automatic bonding evaluation system, prior to production of particleboards. In order to evaluate the quality of lignin-based resins, particleboards were produced and physical and mechanical properties were investigated. These physical properties included internal bond, modules of rupture and modulus of elasticity. Thickness swell and water absorption properties of particleboards bonded with lignin-based resins were also determined. The lignin-based resins have been reported previously in Part I of this study. The results showed that particleboards bonded with phenolated-lignin formaldehyde resins (up to 30% lignin content) exhibited similar physical and mechanical properties when compared to particleboards bonded with PF-com. The work has indicated that phenolated-lignin formaldehyde resins (up to 30% substitution level) can be used successfully as a wood adhesive for constructing particleboard. The performance of these panels is comparable to those of boards made using PF-com resin.     

Mechanical properties of carbon fiber composites modified with graphene oxide in the interphase

The surface topographies of carbon fibers treated by sizing agents with different graphene oxide (GO) content were investigated by scanning electron microscopy. The surface elements compositions of carbon fibers were determined by X‐ray photoelectron spectrometer. The interfacial properties of composites were studied by interfacial shear strength. The thermo‐mechanical properties of two typical specimens (CF‐G0 and CF‐G1 composites) were investigated by dynamic mechanical thermal analysis. The results showed the introduction of GO sheets on carbon fibers surfaces effectively improved the mechanical properties of carbon fibers/epoxy composites. POLYM. COMPOS., 38:2425–2432, 2017. © 2016 Society of Plastics Engineers     

Mechanical,Thermal and Electrical Resisitivity Properties of Thermoplastic Composites Filled with Carbon Fibers and Carbon Particles

Composites consisting of carbon fibers (CF) and carbon particles (CP) in polypropylene (PP) matrix were melt-compounded. Composites were analyzed for their mechanical, electrical and thermal properties. Results indicate that the addition of these fillers improved the mechanical properties of the composites. Thermal conductivity was enhanced as the concentration of fillers was increased. Carbon fibers render the composites electrically conductive so we observed a percolation threshold near 10 wt.% of CF for PP/CF (PP and CF composite) and near 25 wt.% of CP for PP/CP (PP and carbon particle composite). All the results indicated that carbon fibers are more effective in improving the properties as compare to the carbon particles.     

高温热处理后炭纤维表面微观形态

炭纤维的表面微观形态对其力学性能有很大影响，选择国产和日本东邦公司的炭纤维，对其进行高温热处理（1800～2500℃），研究了热处理温度对炭纤维力学性能、密度的影响。用SEM观察了热处理前后炭纤维的表面微观形态变化，讨论了表面缺陷产生的原因。     

Lyocell fibers as the precursor of carbon fibers

In this work, Lyocell fibers, used as carbon fiber precursors, were investigated. Lyocell fibers used for the carbon precursors and the carbon fibers themselves were produced in our laboratory. The mechanical properties morphology and structure of the precursors and the obtained carbon fibers were studied and compared to those of rayon. The results show that Lyocell fibers have higher tenacity and modulus, and better thermal stability than rayon fibers. Scanning electron microscopy (SEM) experiments show that Lyocell precursors have round cross‐sections and fewer defects in the fibers, while rayon fiber has an oval cross‐section and many defects. Wide angle X‐ray diffraction (WAXD) results for the Lyocell precursors indicate that the degree of crystallinity of the Lyocell precursor is higher than that of a rayon precursor. They also show that Lyocell based carbon fibers have better mechanical properties than those that are rayon‐based. WAXD data of the obtained carbon fibers show that the crystallinity of Lyocell‐based carbon fiber is higher than that of rayon‐based carbon fiber. It is concluded that the Lyocell fibers are better precursors for carbon fibers than rayon. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1941–1947, 2003     

Lyocell纤维原丝的性能对碳纤维强度的关联分析

运用灰色系统方法对新型纤维素原丝Lyocell纤维的性能与碳纤维强度之间的关系进行了关联分析，结果表明：Lyocell纤维的强度、纤度和断裂强力对碳纤维的强度有很大的影响，而对伸长和模量的影响较小。     

The influence of pre-carbonization on the properties of PAN-based carbon fibers developed by two-stage continuous carbonization and air oxidation

The Properties of three kinds of carbon fibers, which were pre-carbonized at 500, 550, and 600°C during two-stage continuous carbonization, were measured after being air oxidized for periods of 1 to 6 min at 550°C. The effects of precarbonization temperatures on mechanical properties, density, morphology, elemental compositions, and microstructure of the carbon fibers are discussed. The pre-carbonization process affected strongly the surface properties and mechanical properties of the final carbon fibers, as measured after air oxidation. Carbon fibers measured one to six min after air oxidation showed a different oxidation behavior in the surface morphology for each pre-carbonization temperature. Optimum conditions not only improved the tensile strength and modulus by over 50%, but also increased the density and oxygen content.