石英纤维布的界面处理对氰酸酯基胶膜性能的影响

分别采用烧蚀法和KH550/乙醇溶液对石英纤维布表面进行处理,将处理后的石英纤维布与改性氰酸酯树脂复合制备了氰酸酯/石英纤维布载体胶膜。研究结果表明,经过0.5%KH550溶液处理后的石英纤维表面形成一层均一的界面层,与氰酸酯树脂间的界面强度(IFSS)为62.1MPa,相比经过烧蚀法处理纤维的IFSS提高约90%。随着KH550浓度增加,氰酸酯/石英纤维布载体胶膜的剪切强度和石英纤维布界面硅元素的含量均呈现先增高后降低的趋势。采用0.5%KH550溶液对石英纤维布处理后,制备的氰酸酯/石英纤维布载体胶膜的综合性能最佳,400℃剪切强度为6.4MPa,400℃老化1h后强度保持率为90.2%。     

表面处理对环氧树脂/PBO纤维界面剪切强度的影响

采用了磺化聚芳酰胺(SPA)和固化剂593分别对PBO纤维进行表面处理,用钢针将配好的环氧树脂基体溶液似微球状滴在固定在试样架上的PBO纤维上,考察了处理前后PBO纤维与环氧树脂界面剪切强度的变化。结果表明,两种表面处理对PBO纤维与环氧树脂基体的界面剪切强度都有贡献,其中固化剂处理能显著提高界面剪切强度,改变了界面破坏模式,使PBO纤维与环氧树脂基体的界面剪切强度最高可达19.41 MPa,比未处理时的界面剪切强度提高95%。     

多壁碳纳米管/玻璃纤维/环氧树脂界面粘结特性研究

本文对一种多壁碳纳米管进行表面酸化和胺化改性处理,通过超声波分散制备碳纳米管/玻璃纤维/环氧树脂单丝复合试样,采用单丝断裂法研究碳纳米管对玻璃纤维/环氧树脂界面粘结特性的影响。实验结果表明,加入碳纳米管后环氧树脂弯曲性能提高,单丝复合体系的拉伸应力-应变曲线在屈服点之后产生波动。通过比较纤维断点数-应变曲线、偏光下纤维断点形貌以及断口形貌SEM图像发现,对于玻璃纤维体系,加入硅烷偶联剂KH560后,碳纳米管可明显提高玻璃纤维/环氧界面粘结强度,并以胺化碳管改性体系影响最为显著。     

复配酰胺酸乳液改性玻璃纤维增强环氧树脂界面性能的研究

实验合成了酰胺酸乳液(SA-1),并添加聚乙烯吡咯烷酮进行复配(SA-2),通过纳米粒度分析仪、透射电子显微镜(TEM)和傅里叶红外光谱仪(FT-IR)测定乳液粒径及干燥成分的官能团结构。利用扫描电子显微镜(SEM)和原子力显微镜(AFM)研究处理前后玻璃纤维的表面形貌,并分别用单丝拉伸和微脱黏法测定单纤维的拉伸性能和复合材料的界面剪切性能(IFSS)。结果表明,SA-2乳液平均粒径为99 nm,分布范围为21 nm~220 nm,优于SA-1。SA-1乳液涂覆处理的膜层光滑,平均厚度为0.20μm,而SA-2处理后,玻璃纤维的表面粗糙度增大,膜层厚度为0.12μm。SA-1处理后玻璃纤维单丝拉伸性能从1.401 GPa降至1.369 GPa,GF/环氧树脂复合材料IFSS从20.06 MPa增至26.84 MPa;SA-2处理后单丝拉伸强度降至1.383GPa,复合材料IFSS为32.70 MPa,提升了63.01%。     

芳纶纤维的热氧化处理及对环氧树脂界面黏结的影响

采用红外光谱(FTIR)、热重(TG)、差示扫描量热(DSC)对芳纶纤维在N_2和空气气氛下的热行为进行了研究,并以透射电镜(TEM)、界面剪切强度(IFSS)研究了芳纶纤维的空气热氧化处理及对其环氧树脂界面黏结的影响。结果表明:芳纶纤维在空气条件下,150～200℃温度范围内,仅仅是纤维表层上浆剂的挥发。250℃以上会出现分子链的氧化,同时纤维表层分子链能够重排使得氢键增强。高温过程中芳纶纤维的分子链苯环C—H被氧化成—C—OH、—COOH,从而使纤维表面极性增强。极性的结构有利于与环氧树脂的界面反应,使纤维与环氧树脂间形成40～50 nm的界面层。热处理后,芳纶纤维与环氧树脂微滴间界面剪切强度值增至18.05 MPa,与原丝相比增加了11.9%。同时,高温氧化后的芳纶纤维/环氧树脂界面黏合增强,复合材料的层间剪切强度为76.2 MPa,与原丝相比提高16.16%。     

氧气低温等离子体对PBO纤维的表面改性

采用氧气低温等离子体对聚对苯撑苯并双噁唑(PBO)纤维进行表面改性,讨论了处理时间、处理功率及气压对PBO纤维单丝强度、与环氧树脂基体的界面剪切强度(π_(IFSS))、形态结构、表面元素组成和亲水性的影响。结果表明:在处理时间为2.5 min,处理功率为30 W,处理气压为50 Pa的最佳工艺条件下,经氧气等离子处理后的PBO纤维与环氧树脂的π_(IFSS)比原丝提高60%,达9.38 MPa,与水的接触角也从105°下降到72°。     

聚吡咯层对碳纤维/环氧树脂复合材料界面粘结性能的影响

以三氯化铁为氧化剂,采用吡咯液相沉积聚合方法制备聚吡咯-碳纤维(PPy-CF),然后与环氧树脂(EP)复合,制得PPy-CF/EP复合材料,并对其进行拉伸性能测试,研究了聚合温度对PPy-CF/EP复合材料界面剪切强度(IFSS)的影响。结果表明:在CF表面吡咯沉积聚合最佳工艺条件为聚合温度70℃,时间30min,经过吡咯沉积聚合改性后,得到的PPy-CF/EP复合材料的IFSS有所提高;最佳条件下制得的PPy-CF/EP复合材料的IFSS是CF/EP复合材料的1.24倍;在PPy-CF中,PPy与CF之间无化学键作用,PPy-CF/EP复合材料的IFSS与PPy-CF表面含氧基团和粗糙度有关;吡咯化学沉积聚合改性是一种提高纤维与树脂界面粘结性能的有效方法。     

PAMAM接枝改性碳纤维表面及分子动力学模拟

采用化学法将聚酰胺-胺树枝状大分子(PAMAM)接枝在T700碳纤维(CFs)表面,对比了不同代数PAMAM分子接枝前后CFs表面的微观形貌,并对CFs/环氧微复合材料的界面剪切强度(IFSS)进行测试及材料拉脱断口处形貌观察。与未处理纤维相比,经过G1.0代PAMAM接枝处理后的复合材料IFSS值提高了30.37%。采用Materials Studio程序包,建立碳纤维、环氧树脂及两者间界面的结构模型并进行优化,通过分子动力学模拟并计算了界面相互作用能,结果表明,引入PAMAM分子会提高CFs与环氧树脂间的界面结合能,与实验结果一致。     

油水分离聚结材料的制备与性能研究

研制了纳米颗粒沉积玻璃纤维作为新型聚结材料,考察了分散液浓度、沉积时间和纳米颗粒尺寸等因素对纳米颗粒在纤维表面沉积情况的影响,检测了表面纳米颗粒沉积玻璃纤维的脱水性能。结果显示分散液浓度和浸泡时间对纳米颗粒的沉积情况没有明显影响,但分散液浓度越高,未沉积在纤维表面的SiO_2颗粒越多;颗粒尺寸越小,在纤维表面沉积效果更好;其中经20 nm粒径SiO_2分散液处理的纤维聚结过滤效果最佳。     

表面处理对剑麻纤维性能及与淀粉相容性的影响

采用碱处理、硅烷偶联剂处理以及两者复合的处理方法对剑麻纤维进行表面改性,研究了不同处理方法对剑麻纤维的性能以及剑麻纤维/淀粉复合材料界面粘结性能的影响。通过傅立叶变换红外光谱仪、热重分析仪、扫描电子显微镜和万能试验机对不同处理的剑麻纤维进行表征,使用拔出实验测试剑麻/淀粉复合材料的界面粘结情况,并采用二参数威布尔模型计算拉伸强度和界面剪切强度。结果表明,所有处理方法都能提高剑麻纤维的热稳定性和界面剪切强度。与未处理纤维相比,碱处理后的剑麻纤维与淀粉的界面剪切强度最高,为2.011 MPa,提高了19%。     

The effect of silica (SiO2) nanoparticles and ammonia/ethylene plasma treatment on the interfacial and mechanical properties of carbon-fiber-reinforced epoxy composites

A nanoparticle dispersion is known to enhance the mechanical properties of a variety of polymers and resins. In this work, the effects of silica (SiO₂) nanoparticle loading (0–2 wt%) and ammonia/ethylene plasma-treated fibers on the interfacial and mechanical properties of carbon fiber–epoxy composites were characterized. Single fiber composite (SFC) tests were performed to determine the fiber/resin interfacial shear strength (IFSS). Tensile tests on pure epoxy resin specimens were also performed to quantify mechanical property changes with silica content. The results indicated that up to 2% SiO₂ nanoparticle loading had only a little effect on the mechanical properties. For untreated fibers, the IFSS was comparable for all epoxy resins. With ethylene/ammonia plasma treated fibers, specimens exhibited a substantial increase in IFSS by 2 to 3 times, independent of SiO₂ loading. The highest IFSS value obtained was 146 MPa for plasma-treated fibers. Interaction between the fiber sizing and plasma treatment may be a critical factor in this IFSS increase. The results suggest that the fiber/epoxy interface is not affected by the incorporation of up to 2% SiO₂ nanoparticles. Furthermore, the fiber surface modification through plasma treatment is an effective method to improve and control adhesion between fiber and resin.     

微脱黏法在碳纤维/环氧树脂界面性能评价中的应用

利用微脱黏法测定碳纤维/环氧树脂复合材料的界面剪切强度,并分析了造成测试结果分散的影响因素.结果表明:在脱黏过程中,最大脱黏力随碳纤维埋人环氧树脂内长度的增加而线性递增,当埋人长度超过一定值后最大脱黏力趋于稳定:碳纤维与环氧树脂间的接触角对复合材料界面剪切强度有一定影响,接触角越大,界面剪切强度越高;测试结果的分散性与树脂微球的半月板区域、钳口区等因素有关;未经表面处理的碳纤维增强环氧树脂复合材料的界面剪切强度仪为39.4 MPa,低于处理后的复合材料(60.6 MPa).     

Surface modification of ultra-high strength polyethylene fibers for enhanced adhesion to epoxy resins using intense pulsed high-power ion beam

The effects of intense pulsed high power ion beam (HPIB) treatment of ultra-high strength polyethylene (UHSPE) fibers on the fiber/epoxy resin interface strength were studied. For this study, argon ions were used to treat Spectra? 1000 (UHSPE) fibers in vacuum. Chemical and topographical changes of the fiber surfaces were characterized using Fourier transform infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), dynamic wettability measurements, and scanning electron microscopy (SEM). The fiber/epoxy resin interfacial shear strength (IFSS) was evaluated by the single fiber pull-out test. The FTIR-ATR and XPS data indicate that oxygen was incorporated onto the fiber surface as a result of the HPIB treatment. The wettability data indicate that the fibers became more polar after HPIB treatment and also more wettable. Although the total surface energy increased only slightly after treatment, the dispersive component decreased significantly while the acid-base component increased by a similar amount. SEM photomicrographs revealed that the surface roughness of the fibers increased following the HPIB treatment. The single fiber pull-out test results indicate that HPIB treatment significantly improved the IFSS of UHSPE fibers with epoxy resin. This enhancement in IFSS is attributed to increased roughness of the fiber surface resulting in mechanical bonding and in increased interface area, increased polar nature and wettability, and an improvement in the acid-base component of the surface energy after the HPIB treatment.     

The interfacial strength and fracture characteristics of ethanol and polymer modified carbon nanotube fibers in their epoxy composites

Carbon nanotube (CNT) fibers spun from CNT arrays were used as the reinforcement for epoxy composites, and the interfacial shear strength (IFSS) and fracture behavior were investigated by a single fiber fragmentation test. The IFSS between the CNT fiber and matrix strongly depended on the types of liquid introduced within the fiber. The IFSS of ethanol infiltrated CNT fiber/epoxy varied from 8.32 to 26.64 MPa among different spinning conditions. When long-molecule chain or cross-linked polymers were introduced, besides the increased fiber strength, the adhesion between the polymer modified fiber and the epoxy matrix was also significantly improved. Above all, the IFSS can be up to 120.32 MPa for a polyimide modified CNT fiber, one order of magnitude higher than that of ethanol infiltrated CNT fiber composites, and higher than those of typical carbon fiber/epoxy composites (e.g. 60–90 MPa). Moreover, the composite IFSS is proportional to the tensile strength and modulus of the CNT fiber, and decreases with increasing fiber diameter. The results demonstrate that the interfacial strength of the CNT fiber/epoxy can be significantly tuned by controlling the fiber structure and introducing polymer to optimize the tube–tube interactions within the fiber.     

界面结合对GF/PDCPD复合材料性能的影响

界面结合性能对制备性能优异的复合材料具有重要意义。通过对双环戊二烯（DCPD）与玻璃纤维（GF）的浸润性进行研究，将其与等效环氧树脂比较，开发了一种与玻璃纤维具有较好结合性的DCPD树脂，用其制备出一种综合性能优异的玻璃纤维增强PDCPD基复合材料。通过动态接触角、90?拉伸强度和层间剪切强度实验，测定了不同树脂与玻璃纤维之间的粘附力，提供了玻璃纤维与不同树脂界面性能差异。结果表明，SCB-600 DCPD树脂与玻璃纤维的结合性较优，动态接触角为60.35??0.3?，90?拉伸强度为(42.3?1.6) MPa，层间剪切强度为(61.3?3.2) MPa，与1564环氧树脂相当。进一步优化了DCPD树脂质量分数，当树脂质量分数为30%?2%时，SCB-600 DCPD复合材料具有相对最优的力学性能，材料拉伸强度为(1180.1?4.1) MPa，弯曲强度为(1060.4?4.6) MPa，缺口冲击强度为(145.3?4.8) KJ/m2。其弯曲和拉伸强度与玻璃纤维增强环氧树脂基复合材料的性能基本相当，但缺口冲击强度优于1564环氧树脂。     

Effects of surface treatment of carbon fiber: Tensile property,surface characteristics,and bonding to epoxy

In this article, effects of electrochemical oxidation and sizing treatment of PAN‐based carbon fibers (CFs) on the tensile properties, surface characteristics, and bonding to epoxy were investigated. As found, the electrochemical oxidation improves the tensile strength of single CF by 16.0%, due to weakening the surface stress concentration and smoothing the surface structure. Further sizing treatment shows a negligible effect on the tensile strength. Both oxidation and sizing treatments significantly improve the wettability and surface energies of CFs by introducing oxygen‐containing functional groups. Microbond test was conducted to characterize the interfacial shear strength (IFSS) between a single fiber and an epoxy droplet. The oxidation treatment increases IFSS slightly, which is due to the contradictory effects of the formation of chemical bonds between the resin and CFs, and the reduced mechanical interlocking. Further sizing treatment significantly enhances IFSS from 73.6 to 81.0 MPa, due to the formation of vast chemical bonds. Furthermore, the oxidation and sizing treatment can effectively reduce the degradation of IFSS to the hygrothermal ageing for the CF/epoxy system. POLYM. COMPOS., 37:2921–2932, 2016. © 2015 Society of Plastics Engineers     

Effect of ultrasound on wettability between aramid fibers and epoxy resin

Good wetting of reinforced fiber by resin was a main factor in the improvement of the interface adhesion of their composites. Ultrasound with a frequency of 20 kHz was used to improve the wettability between aramid fibers and epoxy resin during the winding process of the composites. The effects of ultrasound on the viscosity and surface tension of epoxy resin and on the surface characteristics of aramid fibers were investigated. The wettability of aramid fibers and treated epoxy resin under different conditions and of aramid fibers and epoxy resin under ultrasonic online treatment were compared. The results indicated that the main action of ultrasound was to force epoxy resin to impregnate aramid fibers, in addition to the influence of ultrasound on the properties of epoxy resin and aramid fibers. The results of microdebond testing showed that the interfacial shear strength (IFSS) of aramid/epoxy composites could be 26% higher than that of untreated composites because of the improved wettability between aramid fibers and epoxy resin subjected to ultrasonic online treatment. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Effect of Halloysite Nanotube Incorporation in Epoxy Resin and Carbon Fiber Ethylene/Ammonia Plasma Treatment on Their Interfacial Property

Abstract

Effects of halloysite nanotube (HNT) loading of up to 2% in epoxy resin on its mechanical properties were characterized. The interfacial property of the resin with carbon fiber nanocomposite was also studied. Single fiber composite (SFC) technique was used to characterize the carbon fiber/epoxy resin interfacial shear stress. Carbon fibers were also coated with ammonia/ethylene plasma polymer to obtain a thin coating of the polymer with amine groups that could react with the epoxy and thus improve the interfacial property. The results indicated that the Young’s modulus of HNT containing nanocomposites increased slightly up to a loading of 0.25% after which it started to decrease. The tensile strength, however, steadily decreased with increasing of HNT loading although the fracture strain did not change significantly. This might be related to the nanotube shape, size and clustering. The interfacial shear strength (IFSS) was also increased slightly with HNT loading. The ethylene/ammonia plasma polymer coated fibers exhibited significantly higher IFSS by over 150%, independent of the HNT loading. The highest IFSS obtained was almost 79 MPa for plasma treated fibers. The results suggest that the carbon fiber/epoxy interface is not affected by the incorporation of up to 1.5% of HNT. Furthermore, the fiber surface modification through plasma polymerization is an effective method to improve and control the IFSS.     

Influence of plasma treatment on properties of ramie fiber and the reinforced composites

In this research, 9 series of ramie fibers were treated under low-temperature plasma with diverse output powers and treatment times. By analysis of the surface energy and adhesion power with epoxy resin, 3 groups as well as control group were chosen as reinforced fibers of composites. The influences of these parameters on the ramie fiber and its composites such as topography and mechanical properties were tested by scanning electron microscopy (SEM), atomic force microscopy (AFM), tensile property and fragmentation test of single-fiber composites. Contact angle and surface free energy results indicated that with the increased treatment times and output powers, surface energy and adhesion work with epoxy resin improved. Compared with the untreated fibers, surface energy and adhesion work with epoxy resin grew 124.5 and 59.1% after 3 min-200 w treatment. SEM and AFM showed low temperature plasma treatment etched the surface of ramie fiber to enhance the coherence between fiber and resin, consequently fiber was not easy to pull-out. After 3 min-200 w treatment, tensile strength of ramie fiber was 253.8 MPa, it had about 30.5% more than that of untreated fiber reinforced composite. Interface shear stress was complicated which was affected by properties of fiber, resin and interface. Fragmentation test showed biggest interface shear stress achieved 17.2 MPa, which represented a 54.0% increase over untreated fiber reinforced composites.     

A Novel Route to Modify the Interface of Glass Fiber-Reinforced Epoxy Resin Composite via Bacterial Cellulose

A simple and novel method to modify the surface of glass material with Acetobacter xylinum bacteria to deposit bacterial cellulose (BC) around glass material during the process of fermentation was described. The modified glass material with more hydrophobic and rougher surface was characterized by FTIR, SEM, XPS, peeling experiments, and water/air contact angle. It was found that heat treatment at 140 ～ 150°C was able to improve the interaction between BC and glass material owing to the increase in chemical bonds between them. The biological modified glass fibers were compounded with epoxy resin. The influence of incubation time and high temperature on the interfacial shear strength (IFSS) between glass fibers and epoxy resin was identified by Microbond Test. The strongest IFSS could be obtained with incubation time of 1 hour and temperature of 140°C, which then offers a biological approach to improve the interface of silicates materials and resin matrix.