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。     

铬酸处理的超高分子量聚乙烯纤维粘接性研究

本文采用不同浓度和温度下的铬酸溶液对超高分子量聚乙烯纤维进行表面处理。通过DSC、DMA、X-衍射和SEM分析纤维的结构,测试了纤维接触角、断裂强度和层间剪切强度。实验结果表明,随着处理液酸浓度的增加,纤维表面刻蚀程度增加,层间剪切强度增大,而纤维表面极性不变;处理时间和溶液温度须控制在一个合适的水平。     

UHMWPE冻胶纺丝中的降解行为及其对纤维性能的影响

采用双螺杆混炼挤出机溶胀、溶解和挤出纺丝技术制备超高相对分子质量聚乙烯(UHMWPE)冻胶纤维,经热管拉伸得到UHMWPE纤维,研究了冻胶纺丝工艺及后续热拉伸对UHMWPE纤维黏均相对分子质量(M_η)的影响,以及M_η与UHMWPE成品纤维力学性能、热性能、抗蠕变性能及耐磨性能的关系。结果表明:螺杆转速、溶解温度及溶液浓度变化引起的物料高温停留时间和受剪切强度变化对UHMWPE分子降解程度有很大的影响,超倍热拉伸工艺对UHMWPE分子降解影响不大;在UHMWPE溶解均匀的情况下,纤维强度、抗蠕变及耐磨性能随冻胶纤维M_η的增大而增大,且纤维结晶度增加,熔点升高;而UHMWPE溶解条件不佳时,冻胶纤维M_η最高,但纤维表面呈现不均匀凸起,纤维综合性能也变差。     

表面改性超高相对分子质量聚乙烯纤维的热性能研究

采用铬酸刻蚀和化学气相沉积聚吡咯处理了超高相对分子质量聚乙烯(UHMWPE)纤维。用DSC、DMA、X-射线衍射及SEM分析了纤维的热力学性能、结晶情况及纤维的表观形貌。结果表明,铬酸处理及化学气相沉积聚吡咯处理后,纤维的耐热性均有所提高,纤维表面变得更加粗糙,其中化学气相沉积聚吡咯处理的纤维变化更明显。     

超高分子量聚乙烯纤维液相氧化改性及其橡胶基复合材料制备

为了增强超高分子量聚乙烯(UHMWPE)纤维与橡胶基体之间的界面粘结强度,采用高锰酸钾溶液对UHMWPE纤维进行表面处理,并将处理后的纤维加入到天然橡胶中制备短切UHMWPE纤维/橡胶复合材料。结果表明,高锰酸钾溶液处理可有效增加纤维表面粗糙度及表面含氧官能团含量,最佳改性工艺条件是:按照m(高锰酸钾)∶m(浓硝酸)=1∶30配置高锰酸钾溶液,在室温下将UHMWPE纤维放入上述溶液中处理1 min。与纯橡胶样品相比,在m(UHMWPE纤维)∶m(天然橡胶)=0~6∶100范围内,随着处理后短纤维质量分数的增加,复合材料的硬度不断增大,最大增加量达到94%;复合材料的撕裂强度先增大后减小,在m(UHMWPE纤维)∶m(天然橡胶)=4∶100时达到最大值,最大增加量达到43%。     

聚烯烃纤维

<正>20141135吡咯沉积聚合技术对UHMWPE纤维性能的影响Wang Wenyu…;Advanced Materials Research,2012,476～478(Pt.2),p.1374(英)在这篇论文中,将两种沉积聚合技术如气相和液相吡咯沉积聚合应用于超高分子质量聚乙烯(UHMWPE)纤维。讨论了沉积技术对纤维表面形态、力学性能、电稳定性以及表面粗糙度的影响。结果表明,沉积技术对UHMWPE纤维的性能有显著影响。经气相沉积聚合处理的纤维具有更细更小的     

紫外辐射接枝改性UHMWPE纤维表面的研究

采用紫外辐射接枝方法对超高相对分子质量聚乙烯(UHMWPE)纤维表面进行改性。探讨了单体种类及浓度、引发剂、抗氧剂、接枝方法等对UHMWPE纤维表面处理效果的影响,测试了以其作为增强材料的复合材料的层间剪切强度。结果表明:在有氧开放体系下,气相接枝效果好于液相接枝;丙烯酰胺单体的接枝效果优于其它单体;接枝率随接枝单体浓度和接枝时间的增加而增加。采用丙烯酰胺为接枝单体,在光强度为86μW/cm~2条件下,对UHMWPE纤维进行紫外辐射接枝改性,按照一定铺层方式制备的环氧基复合材料的层间剪切强度从未处理的14.59MPa提高到17.36MPa。     

电泳沉积时间对SiC_f/SiC复合材料性能的影响

针对电泳沉积结合先驱体浸渍裂解的方法制备SiC_f/SiC复合材料过程,探讨沉积时间对SiC纤维及SiC_f/SiC复合材料性能的影响规律。实验结果得出:随电泳沉积时间的延长,SiC纤维逐渐被腐蚀,致使其单丝强度下降;而在SiC纤维表面覆盖PyC涂层可以有效地保护SiC纤维,由于悬浮液中的通电作用,Py C涂层与SiC纤维的界面结合强度略有降低,纤维单丝强度随电泳时间的延长先增大后减小。5 min的电泳沉积结合9个周期的PIP得到了SiC_f/SiC复合材料最大的弯曲强度为731 MPa,随后其力学性能随着沉积时间的延长先降低后略微回升;SiC_f/SiC复合材料的热导率随沉积时间的延长先增大后减小,10 min电泳沉积得到了常温下SiC_f/SiC复合材料的最大热导率为4.658 W/(m·K)(25℃)。     

超高相对分子质量聚乙烯表面改性及对天然橡胶性能的影响

以过氧化二苯甲酰对超高相对分子质量聚乙烯(UHMWPE)进行表面处理,采用傅里叶变换红外光谱、差示扫描量热仪和热重分析仪进行了表征,并用扫描电镜观察了微观形貌,制备了天然橡胶(NR)/UHMWPE复合材料,研究了改性UHMWPE对NR硫化特性、力学性能及动态力学性能的影响。结果表明,改性后的UHMWPE表面粗糙度增加,熔融温度升高;NR/UHMWPE复合材料的最佳硫化条件为140℃、20 min。随着改性UHMWPE用量的增加,NR/UHMWPE复合材料的邵尔A硬度逐渐增大,拉伸强度逐渐减小。改性UHMWPE与NR基体黏结性较好,改善了复合材料的力学性能和动态力学性能。     

硅烷偶联剂表面改性UHMWPE纤维的工艺优化

以硅烷偶联剂KH-550在不同条件下处理超高相对分子质量聚乙烯(UHMWPE)纤维,采用正交实验方法,以硅烷偶联剂KH-550的浓度(A)、处理温度(B)、处理时间(C)为因素,以UHMWPE纤维的断裂强力、界面剪切强度(τ)为实验指标,研究了硅烷偶联剂KH-550处理UHMWPE纤维的最佳工艺条件。结果表明:UHMWPE纤维断裂强力的影响因素主次顺序为A,B,C,τ的影响因素主次顺序为B,A,C;硅烷偶联剂KH-550处理UHMWPE纤维的最优工艺为硅烷偶联剂KH-550质量分数17.5%,处理温度55℃,处理时间7 h,在此条件下得到的UHMWPE纤维的断裂强力为41.15 cN,断裂强力损失率为2.44%,τ为1.359MPa,τ的增加率为35.22%。     

The relationship between zeta-potential and pull-out shear strength on modified UHMWPE fiber reinforced epoxy composites

UHMWPE fiber exhibits high performance, featuring high tensile strength and modulus, because of its extended chain structure. However, this fiber demonstrates some defects, such as low melting point, creep, and poor interfacial bonding with resin. Therefore, it is still not widely applied in composites. This research attempted to improve the performance by applying interfacial treatment to the fiber, using polypyrrole (PPy) synthesized through oxidation. The interfacial shear strength was evaluated using the results of a pull-out test and a Zeta Potential. The UHMWPE fiber was exposed to PPy treatment at various temperatures. The PPy-modified fiber was then impregnated with epoxy to generate the composites. The effects of the modification were also examined. The performance of the composites was determined by the Zeta Potentials of the fiber and resin, using an EKA electrokinetic analyzer. The interfacial shear strength was determined by the pull-out test. The morphology of fiber was observed by SEM. Results show that the shear strength of the interface between the PPy-treated UHMWPE fiber and epoxy increased 215%. The correlation between the Zeta Potential and the interfacial shear strength was also observed.     

Dynamic mechanical properties of the chemical oxidation on UHMWPE fibers for improved adhesion to epoxy resin matrix

The improved adhesion of an ultrahigh molecular weight polyethylene (UHMWPE) fiber to an epoxy from applying polypyrrole (PPy) was investigated using chemical oxidation polymerization. The interfacial shear strength of the PPy-treated fiber/epoxy was enhanced by 280%. Such an improvement was verified in the previous research using a pull-out test. Dynamic mechanical analysis (DMA) and a morphological examination were performed to evaluate the characteristics of the molecular motions of the UHMWPE fiber/PPy/epoxy composites. Two composite materials, a UHMWPE fiber/PPy and a UHMWPE fiber/PPy/epoxy, were tested by DMA. The results show that both the α_c transitions of the PPy-treated fibers and its composites shift toward higher temperature. In the SEM photos of the UHMWPE fiber/PPy, a very clear roughening effect on the surface of PPy-treated UHMWPE fiber was also observed, which contributes much to the modification of the interface to the epoxy. The results show that an adhesion improvement mechanism for the PPy-treaded UHMWPE fiber is due to the surface roughening effect and the intermolecular interaction. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1387–1395, 1998     

Interfacial bond property of UHMWPE composite

The ultrahigh molecular weight polyethylene (UHMWPE)/hydrocarbon (PCH) composite was prepared by selecting a PCH resin as the matrix, which has the similar structure to UHMWPE fiber. The interfacial bond property between the PCH resin and UHMWPE fiber was investigated by macromechanics, micromechanics, and contact angle. The results show that the PCH resin has good wettability with the UHMWPE fiber surface. The UHMWPE/PCH composite has excellent transverse tensile strength, interlaminar shear strength, and the pull-out strength together with the outstanding interfacial bond property.     

Effects of functional groups and surface roughness on interfacial shear strength in ultrahigh molecular weight polyethylene fiber/polyethylene system

Corona discharge treatment was conducted for ultrahigh molecular weight polyethylene (UHMWPE) fiber. The functional groups and surface roughness of the polyethylene fiber surface were determined by an X‐ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The interfacial shear strength of UHMWPE fiber with HDPE film was determined by microbond pullout method. The interfacial shear strength increased by corona treatment. Then, the effect of the chemical and physical factors on the interfacial shear strength was discussed based on the results of multivariate regression analysis. The results indicated that the contribution of functional groups and surface roughness to the interfacial shear strength was expressed as 50 and 50%, respectively. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 243–249, 1999     

超高相对分子质量聚乙烯纤维的表面改性研究

选择乙烯-醋酸乙烯酯共聚物作为表面改性剂,将其溶解在二甲苯中制成复合萃取液,对超高相对分子质量聚乙烯(UHMWPE)冻胶纤维进行萃取,经干燥和超倍拉伸制得表面改性UHMWPE纤维。对改性前后纤维的表面化学结构、结晶性能、表面粘接性能和力学性能进行了比较。结果表明:加入表面改性剂后,纤维表面引入了极性基团,结晶形态不变,纤维与树脂的抗界面剪切强度大大增加,纤维的力学性能变化不大。     

The role of additional silane coupling agent treatment in oxygen plasma-treated UHMPE fiber/vinylester composites

Ultra-high modulus polyethylene (UHMPE) fiber was treated with oxygen plasma and a silane coupling agent in order to improve the interfacial adhesion between the UHMPE fiber and vinylester resin. The oxygen plasma and γ-methylmethacryloxypropyltrimethoxysilane (γ-MPS)-treated UHMPE fiber/vinylester composites showed a slightly higher interlaminar shear strength than the oxygen plasma-treated UHMPE fiber/vinylester composites. The interfacial adhesion of the oxygen plasma-treated UHMPE fiber/vinylester composites in this study is mainly due to mechanical interlocking between the micropits formed by the oxygen plasma treatment and the vinylester resin. The γ-MPS molecules adsorbed onto the UHMPE fiber surface neither affected the morphology of the UHMPE fiber surface, nor reduced the extent of mechanical interlocking. The improved interfacial adhesion by the γ-MPS treatment is due to enhanced wettability and chemical interaction through the chemically adsorbed γ-MPS molecules, as detected by Fourier-transform infrared (FT-IR) spectroscopy. The γ-MPS molecules adsorbed onto the ultra-high molecular weight polyethylene (UHMWPE) plate surface also reduced the aging effect of the oxygen plasma-treated UHMWPE surface.     

Enzyme‐mediated grafting of acrylamide to ultrahigh molecular weight polyethylene fiber: A novel radical initiation system

The enzyme‐mediated grafting of acrylamide (AM) to ultrahigh molecular weight polyethylene (UHMWPE) fibers using horseradish peroxidase (HRP) was demonstrated. To optimize the reaction condition, the concentrations of monomer, H₂O₂, the initiator, and time were varied. The grafting results were discussed and a reaction mechanism was proposed. Function groups and structural change of the graft copolymer were determined by FTIR spectroscopic and scanning electron microscopy micrographs for proof of grafting and the results were discussed. Results show that the surface of treated fiber becomes rougher than the untreated surface. Compared to unmodified fiber, modified fiber surface had significantly increased the interfacial shear strength, and carbonyl‐stretching regions in the IR spectra. The interfacial shear strength of the UHMWPE fiber increased, clearly indicating that enzymatic‐grafted acrylamide could significantly increase the hydrophilicity of the surfaces of UHMWPE fibers. Moreover, the hydrophilicity of treated fiber depends on the monomer concentration, the initiator concentration, and oxidizing agent concentration as well as the time of the reaction. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1011–1016, 2005     

偶联剂改性UHMWPE纤维表面性能的研究

选用硅烷偶联剂KH-550,KH-560和钛酸酯偶联剂NDZ-201作为表面改性剂,对超高相对分子质量聚乙烯(UHMWPE)冻胶纤维在萃取阶段进行表面处理,经干燥、超拉伸制得表面改性UHMWPE纤维。采用红外光谱仪、接触角测量仪测定了纤维的表面化学结构和表面润湿性能,采用单纤维树脂包埋-拔出法测定了纤维与树脂基体的界面剪切强度,比较了改性前后纤维的力学性能变化。结果表明:改性后纤维表面引入了极性基团,硅烷偶联剂KH-550对UHMWPE纤维的表面改性效果最好。采用质量分数为1%的硅烷偶联剂KH-550溶液处理后,纤维与环氧树脂间的界面剪切强度提高了87.8%,纤维的断裂强度和模量分别提高了6.9%和32.6%。