异氰酸酯基偶联剂改性PAN基碳纤维增强聚三唑复合材料的研究

采用异氰酸酯基偶联剂(A1)对聚丙烯腈(PAN)基碳纤维表面进行处理,制备了碳纤维增强聚三唑(PTA)复合材料;考察了偶联剂A1改性PAN基碳纤维的工艺;对比了溶剂丙酮中水分的影响。结果表明:工业丙酮为溶剂时,加入偶联剂A1缩短了PTA树脂胶液贮存期,需现配现用;偶联剂A1处理PAN基碳纤维,预处理法使T700碳纤维布/增强复合材料剪切强度提高39.2%,迁移法提高9.5%,相比用分析纯丙酮为溶剂的体系,改性效果降低;偶联剂A1在PAN基碳纤维表面生成脲类等极性化合物,增强了与树脂基体的氢键吸附,改善了复合材料的界面粘结,但工业丙酮中的水分消耗了偶联剂的作用基团,过量的杂质削弱了偶联剂与纤维的化学作用。     

苯并噁嗪树脂基复合材料的制备及性能表征

本文采用氧等离子体对碳纤维表面进行活化,后用偶联剂接枝的方法对碳纤维表面进行处理。按照GB3357-82和GB3356-82,对复合材料层间剪切强度和弯曲强度进行测试并研究等离子体处理及偶联剂接枝对碳纤维/苯并噁嗪(Polybenzoxazine,PBOZ)复合材料界面粘接性的影响。通过XPS,SEM对碳纤维表面及复合材料断裂面形貌进行测试,分析界面粘接机制。研究表明,氧等离子体处理使碳纤维表面粗糙度和活性含氧基团含量增加,增加了纤维与树脂之间的粘接性;氧等离子体处理后再进行偶联剂接枝,碳纤维表面的含氧官能团增加,浸润性得到改善,提高了碳纤维/PBOZ复合材料界面粘接性能。     

秸秆纤维增强热塑性树脂基复合材料界面改性研究新进展

秸秆纤维增强热塑性树脂基复合材料是一种用途广泛的新型环保性材料。复合材料的界面相容性会直接影响复合材料的性能,界面改性技术的研究成为近年来研究的热点。本文综述了国内外对秸秆纤维增强热塑性树脂基复合材料界面改性技术的研究现状和新进展,叙述了对于秸秆纤维的几种典型表面处理方法的研究进展;重点分析了等离子体处理和生物酶处理这两种新型处理方法在秸秆表面预处理中的应用情况,并着重阐述了以马来酸酐接枝聚烯烃为主的界面相容剂和以硅烷、钛酸酯为主的低分子量偶联剂对复合材料界面改性效果的影响。此外,论文简要分析了秸秆/树脂复合材料界面改性技术的发展趋势,指出深入研究针对秸秆纤维的复合处理方法以及开发高效、环保和高性价比的界面改性剂是未来进一步改善秸秆/树脂复合材料应用性能的关键。     

碳纤维的改性及其界面性能

采用化学接枝的方法对篮球鞋用碳纤维进行了表面改性处理,将柠檬酸接枝到碳纤维表面制备了碳纤维/环氧树脂复合材料,对比分析了改性前后碳纤维的表面形貌、界面剪切强度和层间剪切强度,并对断口形貌进行了观察。结果表明:经过柠檬酸改性后的碳纤维表面粗糙度明显增加,与树脂基体的结合力最强;碳纤维、氧化后的碳纤维、对苯二胺接枝的碳纤维、聚柠檬酸接枝的碳纤维和二次接枝对苯二胺的碳纤维的界面剪切强度分别为46.8,53.4,68.2,62.4,82.2 MPa,改性碳纤维的界面剪切强度都高于原始碳纤维,二次接枝对苯二胺的碳纤维的界面剪切强度最大;经过表面改性处理的碳纤维的层间剪切强度都有不同程度提高,且二次接枝对苯二胺的碳纤维的层间剪切强度最大。     

芳纶纤维等离子体接枝改性处理研究

采用等离子体接枝对芳纶纤维表面进行改性处理,采用XPS、浸润性、界面剪切强度对等离子体接枝处理前后的表面组成、复合材料界面粘接性能等进行了研究,结果表明:等离子体接枝处理可以有效地提高芳纶纤维表面的极性官能团,增加与基体树脂-环氧树脂的浸润性,进而提高芳纶/环氧复合材料的界面粘接强度.     

碳纳米材料接枝碳纤维的复合材料界面增效研究进展

界面作为复合材料的重要组成部分,起着传递载荷的作用,影响复合材料的整体性能。碳纤维表面属于石墨乱层结构,微晶有序取向,惰性大,不易与树脂基体结合。对碳纤维进行适当的表面改性,增加纤维的比表面积、粗糙度和引入活性官能团,都能改善表面润湿情况,实现机械结合和化学结合,提高复合材料的界面性能。碳纳米材料接枝到碳纤维表面,是提高界面性能的有效方法之一。因此,对碳纳米管、氧化石墨烯接枝碳纤维的制备方法、界面增效设计以及界面增强机制的国内外研究现状进行综述和分析,在此基础上,展望了碳纳米材料接枝碳纤维表面和界面性能评价方法的研究趋势和前景。     

热解沉积结合PAMAM接枝改性碳纤维表面

采用热解沉积结合聚酰胺-胺型树枝状高分子(PAMAM)接枝的改性方式对碳纤维进行表面处理,对比了碳纤维原丝(CFs)、只经热解沉积处理碳纤维(PD-CFs)和沉积结合接枝处理碳纤维(PD-PG-CFs)的表面形貌、表面元素组成和质量分数、与极性液体和非极性液体的接触角、表面自由能的变化;制备了不同处理条件下碳纤维/环氧微复合材料,与未处理的碳纤维原丝相比,经热解沉积处理的碳纤维/环氧复合材料的界面剪切强度(IFSS)提高了26.87%,而经沉积结合PAMAM接枝处理碳纤维/环氧复合材料的IFSS则提高了38.81%。通过纳米压痕测试定量的表征了复合材料中碳纤维、热解碳层和树脂基体3者的模量,结果表明,热解碳层的模量介于碳纤维和树脂之间,它所起到的过渡层效应是复合材料界面性能得到改善的重要原因。     

表面处理对Kevlar纤维复合材料界面结合强度的影响

为改善芳纶纤维增强树脂基复合材料的界面结合强度,用化学处理法对Kevlar-29纤维进行表面处理,并用傅里叶变换红外光谱和扫描电镜等方法对表面接枝进行鉴定,用单丝拔出试验表征芳纶纤维增强树脂基复合材料的界面结合强度。实验结果表明,纤维经过表面改性后,在单丝断裂强度降低不大的情况下,界面剪切强度显著提高。     

农业废弃秸秆纤维填充聚氯乙烯复合材料相容性的实验探究

采用NaOH溶液浸泡、乙酸酐处理、添加硅烷偶联剂KH570和微波辐照的方法对玉米秸秆纤维进行表面处理,探讨不同实验条件下界面的相容性对复合材料力学性能、热稳定性和防水性能的影响。结果表明:碱溶液蚀刻和微波辐照均可以有效降低秸秆纤维的表面极性,并提高纤维在PVC内部的分散性,从而达到增强界面相容性的效果。与碱溶液蚀刻相比,微波辐照改性的复合材料的力学性能、热稳定性能和防水性能均显著提升。硅烷偶联剂KH570和乙酰化处理可以分别在秸秆纤维表面接枝羧基和乙酰基,从而增强复合材料的相容性。同时,由于乙酸酐力学性能较差,偶联剂对复合材料的性能提升效果优于乙酰化的效果。因此,偶联剂的接枝更适用于优化植物纤维填充PVC复合材料的相容性和性能。综合实验结果,通过微波辐照和偶联剂接枝处理提升秸秆纤维填充PVC复合材料的相容性具有更高的效率和更良好的效果。     

碳纤维表面处理技术研究进展

介绍了在碳纤维增强树脂基复合材料中常用的碳纤维表面处理技术,以及不同处理方式对碳纤维力学性能及其增强的聚合物复合材料力学性能的影响。比较了各种表面处理技术的优缺点,并分析了碳纤维表面处理技术的发展趋势。目前,碳纤维的表面处理技术主要有电化学氧化法、偶联剂涂层处理、气相氧化法、液相氧化法和等离子体处理,其中,气相氧化法是目前比较常用的方法,电化学氧化法是目前唯一能够在碳纤维制备时可在线连续运行的技术,且经电化学氧化处理过的碳纤维增强树脂基复合材料的整体性能均得到提高。采用碳纳米管和石墨烯等碳纳米材料对碳纤维进行表面处理已成为新的研究热点,碳纤维表面处理的低成本化、绿色化和连续生产化将是今后的重点研究方向。     

Effect of various methods of pre-treatment of carbon fibers on the mechanical properties of PIP-based ceramics/carbon composites

The purpose of the work was to determine the conditions of CF preparation to obtain carbide composites with favorable mechanical response. The relationships between the interfacial properties of fiber/polymethylsiloxane composite, and mechanical properties of the resulting fiber/carbide composites were investigated. The CF/resin interfacial strength was modified by oxidation of CF surface with nitric acid, silanization, and depositing CNT or a pyrolytic carbon layer (PyC). The study of composite interphases (ILSS and SEM) and surface tests of the modified CF (XPS, FT-IR, wettability measurements) showed different nature of the bonding occurring at the fiber/resin and fiber/ceramics boundary. The CF silanization significantly improved the ILSS between CFs and resin by 38.5%, while reduced flexural properties of carbide composites. The most promising treatment method of CF for PIP-based ceramic composites was modification with PyC, which provided 2 times higher ILSS, 1.5 times higher flexural strength and improved work to fracture (WF) as compared to unmodified CF.     

PE—UHMW纤维／环氧树脂复合材料研究

对超高相对分子质量聚乙烯(PE-UHMW)纤维进行了铬酸液相氧化和纳米二氧化硅溶胶表面涂覆的复合化表面处理，并对PE-UHMW纤维／环氧树脂复合材料进行了界面性能研究。结果表明，单纯的液相氧化和表面涂覆均可以提高复合材料的界面性能，但液相氧化处理时间过长会使纤维强度降低，而复合化处理则具有协同效应，可以不降低纤维强度而大幅度提高复合材料的层间剪切强度，是一种有效的表面处理方法。     

Effects of polyhedral oligomeric silsesquioxane coatings on the interface and impact properties of carbon‐fiber/polyarylacetylene composites

Two kinds of polyhedral oligomeric silsesquioxane (POSS) coatings were used for the modification of the interface in carbon fiber (CF) reinforced polyarylacetylene (PAA) matrix composites. The effects of the organic–inorganic hybrid POSS coatings on the properties of the composites were studied with short‐beam‐bending, microdebonding, and impact tests. The interlaminar shear strength and interfacial shear strength showed that the POSS coatings resulted in an interfacial property improvement for the CF/PAA composites in comparison with the untreated ones. The impact‐test results implied that the impact properties of the POSS‐coating‐treated composites were improved. The stiffness of the interface created by the POSS coatings was larger than that of the fiber and matrix in the CF/PAA composites according to the force‐modulation‐mode atomic force microscopy test results. The rigid POSS interlayer in the composites enhanced the interfacial mechanical properties with a simultaneous improvement of the impact properties; this was an interesting phenomenon in the composite‐interface modification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5202–5211, 2006     

不同方法处理碳纤维增强PTFE复合材料性能的研究

采用两种不同的方法对碳纤维(CF)表面进行处理,一种是先以热空气对CF进行氧化处理,然后用偶联剂进行表面处理;另一种是先用聚四氟乙烯(PTFE)乳液对CF进行浸渍,后用等离子体进行表面处理。研究了不同方法、不同表面处理条件对PTFE/CF复合材料拉伸性能的影响,并应用扫描电镜对拉伸断口形貌进行了分析。结果表明,两种方法都能有效地提高CF与PTFE之间的界面结合力及PTFE/CF复合材料的拉伸性能。     

Interfacial improvement of carbon fiber-reinforced methylphenylsilicone resin composites with sizing agent containing functionalized carbon nanotubes

A liquid sizing agent containing multiwall carbon nanotubes (MWCNTs) was prepared for carbon fiber (CF) reinforced methylphenylsilicone resin (MPSR) composite applications. In order to improve the dispersion of MWCNTs in the sizing agent and interfacial adhesion between CF and MPSR, MWCNTs and CF were functioned by the chemical modification with tetraethylenepentamine (TEPA) used as a MPSR curing agents. The CF before and after the sizing treatment-reinforced MPSR composites were prepared by a compression molding method. The microstructures, interfacial properties, and impact toughness of CF were systematically investigated. Experimental results revealed that a thin layer of MPSR coating containing functionalized MWCNTs (MWCNT-TEPA) was uniformly grafted onto the surface of CF. The sized CF-reinforced MPSR composite showed simultaneously remarkable enhancement in the interlaminar shear strength and impact toughness. Meanwhile, the tensile strength of CF had no obvious decrease after sizing treatment. In addition, the interfacial reinforcing and toughening mechanisms were also discussed. We believe that the facile and effective method in preparing multifunctional fibers provides a novel interface design strategy of carbon fiber composites for different applications.     

Interface improvement of carbon fiber/methylphenylsilicone resin composites by fiber surface coating of polyhedral oligomeric silsesquioxanes

To enhance interfacial properties of carbon fibers (CFs)-reinforced methylphenylsilicone resin (MPSR) composites, we introduced an appropriate interface reinforced by trisilanolphenyl-polyhedral oligomeric silsesquioxanes (trisilanolphenyl-POSS) between CFs and MPSR with a liquid phase deposition strategy. Chemical bonds among silanol groups of trisilanolphenyl-POSS, hydroxyl-functionalized CF (CF–OH), and silanol end groups of MPSR in the coating were expected to be formed through condensation reaction during the prepared process. CFs with and without sizing treatment-reinforced MPSR composites were prepared by a compression molding method. X-ray photoelectron spectroscopy revealed that trisilanolphenyl-POSS particles enhanced the contents of fiber surface oxygen-containing groups and silicon-containing functional groups. Scanning electron microscopy and atomic force microscopy images showed that trisilanolphenyl-POSS nanoparticles have been introduced onto the fiber surface obviously and the surface roughness increased sharply. Dynamic contact angle analysis indicated that trisilanolphenyl-POSS-modified sizing agent could improve the fiber wettability and surface energy significantly. Short-beam bending test and impact toughness test results showed that the interlaminar shear strength and impact resistance of the sized CFs composites were enhanced greatly with increasing amplitudes of more than 35 and 27% in comparison with those of untreated CF composites, respectively. Cryo-fractured surface topographies of composites confirmed that interfacial adhesion between CFs and MPSR has been improved after sizing treatment. Meanwhile, the sizing treatment does not decrease single fiber tensile strength.     

Kevlar纤维的表面改性研究

采用甲苯-2,4-二异氰酸酯(TDI)和环氧树脂(EP)混合制得的表面改性剂对Kevlar纤维进行表面接枝处理,利用扫描电子显微镜观察Kevlar纤维改性前后的表面形貌及改性Kevlar纤维与弹性体间剥离界面的破坏形貌,用衰减全反射傅里叶变换红外光谱仪分析Kevlar纤维改性前后表面化学基团的变化,研究了改性效果和机理。结果表明,TDI和EP发生了化学反应,改性剂可在Kevlar纤维表面引入活性基团,从而显著改善了Kevlar纤维与聚合物基体之间的界面粘合状态。     

炭纤维表面处理对CF／PMR—15复合材料力学性能的影响

研究了炭纤维表面不同处理方法对复合材料力学性能的影响,采用等离子体和等离子体接枝技术对炭纤维表面进行处理后,CF／PMR－15复合材料的界面剪切强度与层间剪切强度均有所提高,随着界面状态的改善,界面剪切强度提高的幅度比层间剪切强度提高的大,本文为指导炭纤维的表面处理,评价处理效果,进一步预报复合材料的宏观性能打下了基础。     

The Effect of Silane Surface Treatment of Carbon Fiber on the Tribological Properties of Bismaleimide(BMI) Composite

Silane surface modification method was used for the surface treatment of carbon fiber to improve the interfacial adhesion of the carbon fiber reinforced bismaleimide(BMI) composite. The surface characteristics of untreated and treated carbon fiber were characterized by Fourier transform infrared (FT-IR) spectroscope. The friction and wear properties of the BMI composites filled with differently surface treated carbon fibers(20 vol%), were investigated on a ring-on-block tribometer. Experimental results revealed that silane treatment largely reduced the friction and wear of CF/BMI composites. Scanning electron microscope (SEM) of worn surfaces of BMI composites showed that surface treated CF/BMI composite had the strongest interfacial adhesion.     

Effect of sizing on interfacial adhesion of commercial high strength carbon fiber‐reinforced resin composites

The influence of sizing agent on interfacial shear strength (IFSS) of carbon fiber/epoxy (CF/EP) and carbon fiber/bismaleimide (CF/BMI) was investigated. Since sizing agent can alter physicochemical properties of CF surface, possible affecting factors, including sizing reactivity, chemical reactions between sizing and resin, wettability of fiber with resin, fiber surface roughness, and chemical composition of fiber surface, were discussed. It is found that contact angle of fiber with resin and sufficient chemical reactions between sizing and resin reveal strong correlation with the interfacial adhesion of CF/EP and CF/BMI, while the effect of surface roughness and the amount of oxygen on the fiber surface are relatively weak. Due to EP type of the composition, the sizing agent tends to improve the wettability of CF with EP, while goes against for the fiber with BMI. POLYM. COMPOS., 254–261, 2016. © 2014 Society of Plastics Engineers