基于UHMWPE纤维低度交联与表面改性制备高模量、高强度UHMWPE/EP复合材料

从工业化生产应用角度研究电晕处理直接作用于超高分子量聚乙烯(UHMWPE)纤维编织布织布表面，探究纤维表面交联和界面改性对复合材料力学性能的影响。利用X射线光电子能谱(XPS)、傅里叶变换红外光谱(ATR-FTIR)和扫描电镜(SEM)对UHMWPE纤维表面物理性质和化学组成进行表征。采用差示扫描量热仪(DSC)对电晕处理前后纤维结晶度和热稳定性进行表征。当电晕处理功率达到3.0 kW时，UHMWPE-C3.0kW/EP复合材料的冲击强度、弯曲强度和弯曲模量达到了167.4 kJ/m²、121.3 MPa和9.3 GPa,相较于未处理UHMWPE/EP复合材料分别增加了31.5%、64.8%和190.6%。结果表明，通过电晕处理强化了纤维表面与树脂界面黏接强度，有利于复合材料对外力的传递分散，并通过强界面破坏吸收能量及UHMWPE纤维的断裂和形变提高了复合材料的抗冲击和抗弯性能。     

低温等离子体处理UHMWPE纤维表面性能的多指标优化

利用正交表安排试验,对超高相对分子质量聚乙烯(UHMWPE)纤维进行空气低温等离子体处理,测试各处理条件下UHMWPE纤维的力学和表面摩擦性能;采用矩阵分析法对多指标正交试验结果进行优化分析,找出最优方案并进行黏着性试验验证。结果表明:经空气低温等离子体处理后,UHMWPE纤维的断裂强度有所减小,表面静、动摩擦因数有较大幅度的提高;处理纤维的最优方案为功率50 W、压强15 Pa、时间150 s,此时纤维的断裂强度损失率仅为2.53%,剥离功为未处理时的4.25倍,说明由矩阵分析法得出的最优方案在保证纤维断裂强度损失很小的情况下,黏着性得到了很大程度的改善。     

不饱和聚酯树脂／大麻纤维复合材料紫外老化性能的研究

采用模压工艺制备不饱和聚酯树脂/大麻纤维复合材料,研究紫外线光老化试验对此种复合材料及氨水处理复合材料力学性能的影响,利用红外光谱(FTIR)技术研究老化前后复合材料结构的变化.研究结果表明,氨水处理大麻纤维可以改善复合材料的拉伸性能以及拉伸模量.未处理及氨水处理的复合材料,在试验一个周期后,两种复合材料的拉伸强度较老化前分别提高了10.8%和19.1%,未处理的复合材料的弯曲强度在两个试验周期时达到最大值.氨水处理的复合材料,在试验的第一周期时,拉伸模量下降最快,进一步老化之后,下降幅度明显减缓.氨水处理的复合材料的拉伸模量在第三个试验周期结束时,弯曲模量和冲击强度比未老化前分别上升6.3%和25.3%.FTIR显示,老化后,两种复合材料的吸收峰强度减弱,但氨水处理的复合材料吸收峰强度比未处理的强.     

改性方法对竹束纤维及其增强环氧树脂复合材料性能的影响

竹青束纤维(BGF)、竹肉束纤维(BMF)分别取自于竹材的竹青或竹肉部位,其微观结构及力学性能等有所差异,但业界关注甚少。为研究改性方法对两种纤维束性能及其增强树脂复合材料性能的影响,使用碱、碱/γ-氨丙基三乙氧基硅烷(KH550)改性处理竹纤维(BGF、BMF)为增强体,制备竹纤维/环氧树脂(BF/EP)复合材料,并通过红外光谱(FTIR)、X射线衍射(XRD)、接触角、力学性能和扫描电镜(SEM)对竹纤维及复合材料的性能进行表征。结果表明,碱(NaOH溶液)处理时,BGF的拉伸强度在5%NaOH溶液处理时最高,提高了28.2%,BMF在1%NaOH溶液处理时达到最大,提高了30.1%;碱/KH550处理时,BGF、BMF的拉伸强度降低;BF/EP复合材料断面微观形貌表明碱、碱/KH550处理的界面性能提升,且其力学性能相比未改性的显著增强,其中碱处理的BGF/EP、BMF/EP复合材料拉伸强度分别提高了27.8%、15.9%,碱/KH550处理的则分别提高38.0%、21.2%;碱处理后BF/EP复合材料弯曲强度提升较大,改性BGF/EP、BMF/EP较未处理的分别提高14.4%、...     

丙烯酰胺接枝海藻酸纤维的耐碱性研究

采用等离子体处理接枝共聚的方法对海藻酸纤维表面接枝丙烯酰胺,以改善纤维的耐碱性,利用红外吸收光谱和扫描电镜对改性纤维进行表征;探讨了等离子体处理纤维的工艺条件,研究了改性纤维的吸湿性和力学性能。结果表明:海藻酸纤维表面已接枝上丙烯酰胺;等离子体处理和接枝反应最佳工艺条件为:放电功率100 W,放电时间4 min,丙烯酰胺质量分数40%,接枝时间60 min。改性后的纤维碱溶解率为0.23%,吸湿性没有显著变化,但断裂强度提高。     

核电用交联三元乙丙绝缘材料热氧老化状态的评估

采用热氧老化法对核电用交联三元乙丙(EPDM)绝缘材料在180℃下进行不同时间的加速老化,对机械性能、绝缘性能、微观形貌、红外光谱等进行测试分析。结果表明:随着老化时间的增加断裂伸长率和拉伸强度呈下降趋势,硬度呈直线上升趋势;随着老化时间增加白度值下降;体积电阻率和介电强度在老化168h前呈现上升趋势,在168h后下降;SEM微观形貌分析显示老化前EPDM橡胶表面比较平整,随着老化时间增加,表面变得粗糙且有孔洞出现;红外光谱分析显示在3687cm~(-1)和1725cm~(-1)处羟基和羰基吸收峰的强度随着老化时间的增加而增大;2916cm~(-1)和2849cm~(-1)处吸收峰强度随着老化时间的增加而降低,峰宽随着老化时间的增加而逐渐增大。     

核电气动橡胶隔膜材料热老化机械性能研究

核电气动阀门用三元乙丙橡胶(EPDM)和丁腈橡胶(NBR)隔膜材料分别在100℃和150℃下进行不同时间的热老化试验,采用万能试验机、邵氏硬度计、拉伸疲劳试验机、扫描电子显微镜、傅里叶红外光谱仪对材料拉伸性能、硬度、疲劳性能、微观形貌等进行测试与表征,结果表明:EPDM材料随着老化时间的增加断裂伸长率和断裂强度呈下降趋势,硬度呈缓慢上升趋势。NBR材料在100℃老化下断裂伸长率缓慢下降,断裂强度缓慢增加,硬度缓慢增加;在150℃老化下断裂伸长率和断裂强度急剧下降,硬度呈直线上升趋势。在相同老化时间下,老化温度越高,EPDM和NBR材料的断裂伸长率和断裂强度越小,硬度越大。EPDM和NBR材料的耐疲劳性能随着老化时间和老化温度的增加,均有一定程度的下降,其中NBR材料耐疲劳性能下降较大;红外光谱分析结果表明,随着老化时间的增加,EPDM材料羟基和羰基吸收峰的强度增大,NBR材料吸收峰强度逐渐减小。SEM微观形貌分析显示,EPDM和NBR样品在老化前表面比较平整,随着老化时间增加,样品表面出现较多的堆积物质,老化温度越高,样品表面越粗糙。     

聚酯/多壁碳纳米管复合导电纤维的制备及性能

以羧基化多壁碳纳米管(MWNT-COOH)为导电填料,采用双螺杆熔融挤出制备聚酯(PET)/MWNT-COOH共混切片,通过熔融纺丝得到PET/MWNT-COOH复合纤维。研究了MWNT-COOH含量和拉伸处理对复合纤维可纺性、导电性能、力学性能和表面形貌等的影响。结果表明:当MWNT-COOH质量分数小于1.0%时,切片具有较好的可纺性,初生纤维的导电逾渗阈值为0.5%~1.0%;MWNT-COOH的加入提高了纤维的断裂强度,当MWNT-COOH质量分数为0.1%时,纤维断裂强度提高约34%,随着MWNT-COOH含量增加,纤维断裂强度的增加幅度逐渐下降;拉伸会使MWNT-COOH沿纤维轴向取向,有利于MWNTCOOH间的互相搭接形成导电通路,提高纤维的导电性能。     

核级聚烯烃绝缘材料老化状态分析

实验选取核用聚烯烃辐射交联绝缘材料,在180℃下对其进行不同时间的热老化,对机械性能、绝缘性能、微观形貌、红外光谱等进行测试分析。结果表明:随着老化时间的增加断裂伸长率呈明显下降趋势,断裂强度先上升后下降;硬度随着老化时间的增加呈上升趋势;老化初期(72 h前)白度值下降明显,72 h后趋于平缓;随着老化时间的增加,体积电阻率呈上升趋势,介电强度呈先增大后下降的趋势;老化初期(72 h前)绝缘材料的介质损耗角正切值明显增大,72h后随着老化时间增加,增加速度减慢逐渐趋于平缓;红外光谱显示,在3700 cm-1和1740 cm-1波数的羟基和羰基吸收峰强度随着老化时间的增加而增大,2917 cm-1和2852 cm-1波数的吸收峰的峰宽随着老化时间的增加而逐渐增大;扫描电子显微镜(SEM)微观形貌显示,随老化时间增加,材料表面变得粗糙。     

聚苯硫醚长丝热稳定性的研究

采用热烘处理方法,研究了聚苯硫醚(PPS)长丝在不同温度条件下的热稳定性能及力学性能。结果表明:PPS长丝在热处理过程中的失重率随温度的提高和时间的延长而增加;断裂伸长率随热处理温度的提高而下降;在80℃恒温下断裂强度几乎不随时间变化,120℃或180℃恒温下断裂强度随热处理时间的延长先增加后减小,但变化不大;当温度为250℃时,断裂强度随热处理时间显著下降;PPS纤维180℃以下性能稳定。     

A study of the influence of controlled corona treatment on UHMWPE fibres in reinforced vinylester composites

In order to illuminate the mechanisms of corona discharge treatment on ultra‐high molecular weight polyethylene (UHMWPE) fibre, the effects of corona treatment power and time are discussed in detail. The surface‐roughness and tensile‐failure characteristics of the polyethylene fibre were determined by a scanning electron microscope (SEM). The photos from the SEM showed that the size and number of the micro‐pits on the fibre surface increase with increase of corona power. The oxygen‐containing groups on the fibre surface could be detected by Fourier‐transform infrared attenuated total reflectance and also increased gradually with increase of corona power. The T‐peel strength of composites increased from the corona treatment, and then showed a maximum value at a corona treatment time about 0.1 s with increase of treatment time. However, the tensile strength of the fibre was reduced with increase of corona power and the failure mechanism obviously changed after the treatment. The ballistic impact energy absorption of UHMWPE fibre/vinylester composite was obtained after fragment simulating projectiles (FSP) impact tests. After 6‐kW corona treatment for 0.075 s, the impact energy absorbed by the laminate reached a maximum value. Copyright © 2003 Society of Chemical Industry     

Influence of oxygen plasma treatment parameters on the properties of carbon fiber

This study is focused on the impact of oxygen plasma treatment on properties of carbon fibers and interfacial adhesion behavior between the carbon fibers and epoxy resin. The influences of the main parameters of plasma treatment process, including duration, power, and flow rate of oxygen gas were studied in detail using interlaminar shear strength (ILSS) of carbon fiber composites. The ILSS of composites made of carbon fibers treated by oxygen plasma for 1 min, at power of 125 W, and oxygen flow rate of 100 sccm presented a maximum increase of 28% compared to composites made of untreated carbon fibers. Furthermore, carbon fibers were characterized by scanning electron microscopy (SEM), tensile strength test, attenuated total reflectance Fourier transform infrared (ATR-FTIR), and Raman spectroscopy analyses. It was found that the concentration of reactive functional groups on the fiber surface was increased after the plasma modification, as well the surface roughness, which finally improved the interfacial adhesion between carbon fibers and epoxy resin. However, high power and long exposure times could partly damage the surface of carbon fibers and decrease the tensile strength of filaments and ILSS of treated fiber composites.     

超声处理对芳纶Ⅲ性能的影响研究

为了改善芳纶Ⅲ的表面状态,以二甲基乙酰胺(DMAc)为超声介质,对纤维进行超声处理,研究了超声处理速率和超声波功率对纤维性能的影响。结果表明:超声处理后,纤维的强度和模量随着超声波功率的增大而下降;超声波处理速率越慢,处理时间越长,纤维的强度和模量下降越明显,纤维表面沟壑越深,比表面积明显增大;纤维拔出强度随超声波功率和超声处理速率的增大而先增大再减小。     

Improvement of the mechanical properties of an ultrahigh molecular weight polyethylene fiber/epoxy composite by corona‐discharge treatment

The interfacial shear strength of an ultrahigh molecular weight (UHMW) polyethylene (PE) fiber/epoxy‐resin system was greatly improved by the corona‐discharge treatment of the fiber. The UHMW PE‐fiber/epoxy‐resin composite was prepared with corona‐discharge‐treated UHMW PE fiber. The mechanical properties of the composite sheet were determined by tensile testing. The tensile strength of the composite was also very much improved. However, the tensile strength of the composite was about one‐half of the theoretical strength. This result was due to the molecular degradation of the PE‐fiber surface caused by surface modification. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1162–1168, 2001     

激光改性玄武岩纤维性能研究

采用高能激光束对玄武岩纤维进行表面改性,并制备玄武岩纤维/环氧树脂复合材料。利用扫描电镜、原子力显微镜、X射线衍射等手段,表征改性前后玄武岩纤维的微观形态、物相结构,系统研究了激光对纤维的微观组织变化、性能等影响规律,并测试了玄武岩纤维/环氧树脂复合材料的力学性能。研究结果表明,随着激光功率的增加,玄武岩纤维表面缺陷深度和缺陷面积增加。当激光功率由0 W提高至120 W时,表面缺陷最大深度由9 nm增加至180 nm,表面缺陷的分布范围由3.5~6.5 nm增加至90~120 nm,表面粗糙度由1.41 nm增加至24.70 nm。激光改性后,玄武岩纤维单丝拉伸性能降低,由于激光对纤维的辐射作用,玄武岩纤维的表面缺陷深度与拉伸强度的关系不符合经典理论。激光改性前后,玄武岩纤维XRD谱峰位基本一致,表面所含元素的种类没有发生变化。激光改性使玄武岩纤维/环氧树脂复合材料的力学性能有所改善,随着激光功率的增加,复合材料的拉伸强度和冲击强度呈先升高后降低的趋势。     

Mechanical properties of corona-modified cellulose/polyethylene composites

The effect of corona treating the surfaces of components on tensile properties of wood fiber linear low-density polyethylene composites has been investigated. Corona treatment results in a significant increase in strength properties of the composites. Yield stress increases after treatment of one or both of the composite components. Pronounced improvement in ductility has been observed for composites containing 15 to 30% of the corona modified fiber. Relevant mechanisms involved are discussed.     

Surface modification of ultra high modulus polyethylene fibers by an atmospheric pressure plasma jet

To improve their adhesion properties, ultra high modulus polyethylene (UHMPE) fibers were treated by an atmospheric pressure helium plasma jet (APPJ), which was operated at radio frequency (13.56 MHz). The surface properties of the fibers were investigated by X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurement. The surface dyeability improvement after plasma treatments was investigated using laser scanning confocal microscopy (LSCM). The adhesion strengths of the fibers with epoxy were evaluated by microbond tests. In addition, the influence of operational parameters of the plasma treatment including power input and treatment temperature was studied. XPS analysis showed a significant increase in the surface oxygen content. LSCM results showed that the plasma treatments greatly increased fluorescence dye concentrations on the surface and higher diffusion rate to the fiber center. The tensile strength of UHMPE fiber either remained unchanged or decreased by 10–13.6% after plasma treatment. The contact angle exhibited a characteristic increase in wettability, due to the polar groups introduced by plasma treatment. The microbond test showed that the interfacial shear strengths (IFSS) increase significantly (57–139%) after plasma treatment for all groups and the optimum activation is obtained at 100°C and 5 W power input. SEM analysis showed roughened surfaces after the plasma treatments. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Effect of the atmospheric plasma treatment parameters on jute fabric: The effect on mechanical properties of jute fabric/polyester composites

The effect of atmospheric air plasma treatment of jute fabrics on the mechanical properties of jute fabric reinforced polyester composites was investigated. The jute fabrics were subjected to different plasma powers (60, 90, and 120 W) for the exposure times of 1, 3, and 6 min. The effects of plasma powers and exposure times on interlaminar shear strength, tensile strength, and flexural strength of polyester based composites were evaluated. The greatest ILSS increase was about 171% at plasma power of 120 W and exposure time of 6 min. It is inferred that atmospheric air plasma treatment improves the interfacial adhesion between the jute fiber and polyester. This result was also confirmed by scanning electron microscopy observations of the fractured surfaces of the composites. The greatest tensile strength and flexural strength values were determined at 120 W for 1 min and at 60 W for 3 min, respectively. Moreover, it can be said that atmospheric air plasma treatment of jute fibers at longer exposure times (6 min) made a detrimental effect on tensile and flexural properties of jute‐reinforced polyester composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

高温碳化工艺与聚丙烯腈基碳纤维力学性能的关联性

考察了2种由不同规格聚丙烯腈原丝制成的碳纤维在高温碳化过程中力学性能与高温碳化工艺的相关性。试验结果表明:碳纤维的拉伸强度随着高温碳化最高温度的提高而增加,两种不同规格碳纤维在高温碳化最高温度分别超过1 500℃和1 550℃后拉伸强度开始呈下降趋势;碳纤维的弹性模量随着高温碳化温度的提高而增加;在高温碳化时间40 s前,碳纤维的力学性能随停留时间延长而提高,这说明40 s之前时间驱动效应明显;在-2.5%~-5.0%牵伸条件下,弹性模量随牵伸率增加而增加,抗拉强度在牵伸率为-3.5%时出现峰值。