取向PAN/MWCNTs与热塑性聚烯烃复合材料的制备及表征

利用静电纺丝并借助高速旋转的滚筒和热牵引作用制备不同取向度的聚丙烯腈/碳纳米管（PAN/MWCNTs）纳米纤维膜,通过高速滚筒和热牵引提高PAN的结晶度从而提高材料的拉伸强度和弹性模量,但会降低断裂伸长率;MWCNTs含量为0.5 %（质量分数,下同）时PAN/MWCNTs力学性能最佳。利用浸渍法将各种取向度的PAN/MWCNTs纳米纤维膜与热塑性弹性体（POE）制备成一系列POE/PAN/MWCNTs复合材料（POE/PM）。结果表明,高取向度POE/h?P2M复合材料的拉伸强度比不取向POE/u?PME复合材料高71 %,拉伸强度显著提高,断裂伸长率则减小,PAN/MWCNTs纳米纤维膜含量为6.7 %时,复合材料的力学性能最佳。     

玻璃纤维增强尼龙66复合材料的结构与性能

使用双螺杆挤出机,采用共混改性方法制备玻璃纤维(GF)增强尼龙66(PA 66)复合材料(GF-PA 66),并对其结构、热性能和力学性能进行了表征。结果表明:制备的GF质量分数分别为20%,25%,30%的GF-PA 66复合材料的密度均低于1.4 g/cm~3,GF在GF-PA 66复合材料体系中呈现纤维交错复杂的网络结构;GF-PA 66复合材料的起始热降解温度均在320℃以上,具有较好的耐热性;随着GF含量的增加,GF-PA 66复合材料的拉伸强度、弯曲强度、弯曲模量升高,当GF质量分数达到30%时,复合材料的拉伸强度为147.4 MPa,比纯PA 66提高了75%,弯曲强度达到202 MPa,比纯PA 66提高了112%,弯曲模量达到7 783.3 MPa,比纯PA 66提高了175%;随着GF含量的增加,GF-PA 66复合材料的悬臂梁冲击强度先降低后升高,当GF质量分数为30%时,复合材料的悬臂梁冲击强度高于纯PA 66。     

纤维表面改性对PA66/玄武岩纤维复合材料性能影响

以CO_2和缩水甘油醚为原料合成了环状碳酸酯,通过环状碳酸酯与偶联剂KH–550的氨基反应制备两种新型表面改性剂,与KH–550分别对玄武岩纤维(BF)进行改性,得到三种改性纤维KBF,KBF–P,KBF–B。采用双螺杆挤出机共混制备了改性玄武岩纤维增强尼龙66(PA66)复合材料,考察其力学性能和吸水率;采用扫描电子显微镜、热同步分析仪对复合材料的微观结构和热稳定性进行研究。结果表明,与未改性的复合材料相比,纤维质量分数为20%的PA66/KBF–B复合材料的拉伸强度、弯曲强度、无缺口冲击强度分别提高了5.5%,5.9%,25.5%;随着KBF–B含量的增加,PA66/KBF–B复合材料的力学性能均得到提高,当KBF–B质量分数达到40%时,PA66/KBF–B的拉伸强度、弯曲强度、无缺口冲击强度比纯PA66提高了161.1%,148.7%,112.7%,且优于相同纤维质量分数的PA66/玻璃纤维复合材料;PA66/KBF–B复合材料的饱和吸水率仅为3.8%且具有优良的热稳定性。KBF–B表面粗糙,与PA66具有良好的相容性。     

透明尼龙PA6T/6I在GF增强PA66体系中的应用

采用尼龙66 (PA66)和透明尼龙PA6T/6I为基体树脂,用熔融共混改性的技术方法制备PA66/PA6T/6I/GF复合材料,考察了透明尼龙PA6T/6I含量对复合材料的熔融结晶行为、热变形温度(HDT)、力学性能、表面性能的影响。结果表明,当玻璃纤维含量为30%的情况下,在透明尼龙树脂PA6T/6I用量不高于基体树脂含量的20%时,改性复合材料熔融结晶行为与PA66类似,复合材料制品表面的浮纤问题得到解决,比未添加透明尼龙PA6T/6I的复合材料相等的拉伸强度和弯曲强度分别提高27%和40%,简支梁和悬臂梁缺口冲击强度则分别提高了26%和40%,吸水率提高了30%,具有优异的综合性能和尺寸稳定性。     

炭纤维增强尼龙复合材料性能及产品应用研究

研究了炭纤维用量对炭纤维/PA66复合材料力学性能的影响,炭纤维长度、分布、含量对炭纤维/PA66复合材料体系摩擦磨损性能的影响。结果表明:复合材料的拉伸强度随着炭纤维用量增加而增大,但质量分数超过15%后,增幅缓慢。在同一载荷下,随着炭纤维用量的增加,复合材料体系的摩擦系数先降低后升高;炭纤维质量分数20%时,复合材料体系的摩擦系数最小,较PA66树脂降低了1/3;相容剂、耐磨助剂用量对炭纤维/PA66复合材料扶正器专用料体系影响较大,适当的用量可以提高扶正器的使用寿命。     

分散相含量对PP/PA66原位微纤复合材料微观形态和性能的影响

为解决玻璃纤维、碳纤维及芳纶纤维等增强聚丙烯(PP)出现的生产成本高、工艺复杂、能耗较高及难以回收等问题,采用一次挤出熔融、二次挤出拉伸的方法制备了PP/尼龙66 (PA66)原位微纤复合材料(MFCs),并通过与普通PP/PA66共混物对比,分析了分散相含量对形成微纤形貌的影响及原因。探究了分散相含量对复合材料的结晶性能、流变行为以及力学性能的影响。结果表明,PA66微纤可以对基体PP异相成核起到促进作用;随着PA66含量的增加,复合材料的储能模量、损耗模量和复数黏度也随之增大;当PA66质量分数为15%时,MFCs的拉伸强度和弯曲强度均达到一个最优值,分别为36.96 MPa和52.4 MPa,比普通共混材料增加了53.3%和40%,当PA66质量分数为25%时,MFCs的冲击强度最大增加了94%。     

玻璃纤维改性PA66冲击强度的影响因素分析

以质量分数33%的玻璃纤维改性聚己二酰己二胺(PA 66)切片为基础,分析了基料黏度、玻璃纤维粗细、增韧剂、挤出工艺等对PA 66复合材料的冲击性能的影响。结果表明:随基料树脂黏度增大,PA 66复合材料的冲击性能增加,其中无缺口冲击强度增加幅度大;玻璃纤维直径越小,PA 66复合材料的冲击强度越高,玻璃纤维直径以13~15μm为宜;增韧剂本体强度小,增韧效果好,马来酸酐接枝茂金属乙烯-辛烯共聚物(POE-g-MAH)的性价比最佳;PA 66复合材料缺口冲击强度随增韧剂用量增加而增加,无缺口冲击强度呈先增大后减小再增大的趋势,复合材料中加入增韧剂质量分数2.5%较适宜;采用高温低转速挤出工艺时PA 66复合材料冲击强度较好。     

原位微纤增强复合材料的结构与性能

采用熔融挤出——热拉伸——牵引拉伸制备了HDPE/PA6原位成纤增强复合材料,通过SEM分析了分散相PA6含量对其在基体中的形态及分布的影响;讨论了两种加工方式条件下分散相PA6含量对复合材料拉伸性能和冲击韧性的影响以及加工方式对复合体系力学性能的影响。结果表明：在原位成纤增强复合材料中存在直径为2～5 μm的纤维,当HDPE/PA6质量比为85/15时,微纤直径约为3 μm,此时,与普通共混复合材料相比,原位成纤增强复合材料的拉伸强度提高了6.9%,拉伸模量提高了14.8%,冲击强度提高10.03%。     

水下搅拌摩擦加工制备碳纳米管增强PE-HD结构与拉伸性能研究

通过水下搅拌摩擦加工技术制备多壁碳纳米管（MWCNTs）增强高密度聚乙烯（PE-HD）复合材料,并研究了旋转速度和MWCNTs含量对复合材料结构和性能的影响。结果表明,MWCNTs在基体中以云状形式分布,组织相对均匀;MWCNTs含量为从1 %（质量分数,下同）增加到2 %时,复合材料拉伸强度随着旋转速度的增加先增大后减小;MWCNTs含量为4 %时,复合材料拉伸强度随着旋转速度的增加而减小;PE-HD的结晶度随着MWCNTs含量的增加而下降。     

POE-g-MAH改性PA6/BF复合材料的力学和摩擦磨损性能研究

采用马来酸酐接枝聚烯烃弹性体(POE-g-MAH)为增韧剂,通过熔融挤出制备马来酸酐接枝聚烯烃弹性体(POE-g-MAH)/尼龙(PA6)/玄武岩纤维(BF)复合材料,研究了POE-g-MAH含量对PA6/BF复合材料力学性能和摩擦磨损性能的影响。结果表明,POE-g-MAH粒子的加入显著提高了复合材料的冲击强度,当POE-g-MAH质量分数为20%时,POE-g-MAH/PA6/BF复合材料的冲击强度达到13.6 k J/m~2,比PA6/BF(4.7 k J/m~2)提高了190%,拉伸强度与弯曲强度分别下降40%和41%。随着POE-g-MAH含量的增加,摩擦因数随着POE-g-MAH含量增加呈现先减小后增大趋势,磨损逐渐增大。     

碳纳米管/石墨烯协同改性碳纤维复合材料的制备及性能

利用偶联剂（KH570）改性的石墨烯（GO）和酸化的多壁碳纳米管(MWCNTs)协同改性聚丙烯腈（PAN）基碳纤维制备得到PAN/MWCNTs/GO基碳纤维（MPG）,以此为原料,采用湿法造纸技术,制备PAN/MWCNTs/GO基碳纤维复合材料（MPG P）。利用傅里叶变换红外光谱仪、扫描电子显微镜,对MPG纤维进行表征,并利用四探针测试仪、万能试验机和多孔材料分析仪,研究了MPG-P材料的导电性能、力学性能、孔径分布以及孔隙率。结果表明,当MWCNTs/GO含量为0.2 %（质量分数,下同）时,MPG P表现出最佳的拉伸强度(37.21 MPa),电阻率为13.17 mΩ·cm,孔隙率为63.7 %;当MWCNTs/GO=1/2（质量比,下同）时,表现出最佳的拉伸强度(40.13 MPa),比纯PAN复合材料(30.18 MPa)提高了32.97 %,电阻率为13.52 mΩ·cm,孔隙率为65.2 %。     

Influence of surface modification of carbon nanotube on microstructures and properties of polyamide 66/multiwalled carbon nanotube composites

The melt‐mixing polyamide 66 (PA66) composite samples that incorporated pure, acid‐ and amine‐functionalized multiwalled carbon nanotubes (MWCNTs) were prepared in order to enhance mechanical and frictional properties of PA66 composites. The homogeneous dispersion of amine‐functionalized MWCNTs (D‐MWCNTs) in PA66 matrix was observed from the significantly uniform morphology of tensile fractured surface of the composites. Differential scanning calorimetry measurement indicates that D‐MWCNTs acted as effective nucleation agent for PA66 matrix and the crystallinity of PA66 was increased. The fracture stress and tensile modulus of the composites were significantly improved with the incorporation of D‐MWCNTs, owing to the good dispersion of D‐MWCNTs. Compared with PA66, the PA66 composites with 1.0 wt% D‐MWCNTs were improved considerably in both wear and friction properties owing to the change of the tribological mechanisms. The good dispersion of D‐MWCNTs in PA66 and good interface compatibility between D‐MWCNTs and PA66 favored the formation of a thin layer on the contact surfaces during wear and friction test, which played an important role in reducing wear and friction of the composite and in suppressing the transverse cracks. These results prove the importance of D‐MWCNTs in a positive change of the mechanical and frictional properties of PA66 composites and suggest the applicability prospect of PA66/D‐MWCNTs composites in engineering components.POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

碳纳米管改性方法对聚酰胺11性能影响研究

采用酸处理和聚乙烯亚胺(PEI)表面修饰两种方法对多壁碳纳米管(MWCNTs)进行改性,将改性碳纳米管与聚酰胺11(PA11)熔融共混,制备了聚酰胺11/酸刻蚀碳纳米管(PA11/a-MWCNTs)和聚酰胺11/聚乙烯亚胺接枝碳纳米管(PA11/PEI-MWCNTs)复合材料,并通过扫描电子显微镜(SEM)、热重分析仪...     

长玻纤增强尼龙66复合材料性能的研究

在自制装置中用硅烷偶联剂KH550对长玻纤(LGF)进行表面处理后,采用熔融共混法制备了尼龙66/长玻纤复合材料。采用微机全自动热膨胀系数测定仪记录了玻纤增强尼龙66复合材料的热膨胀曲线,分析了玻纤含量、温度对复合材料热膨胀系数的影响,结果表明,随着玻纤含量的增加,复合材料的热膨胀系数显著下降,最大降低了74.2%;随着温度的升高,复合材料的热膨胀系数先增大后减小最后趋于平衡,转折温度在37℃左右。测试了复合材料的力学性能,结果显示复合材料的拉伸强度、弯曲强度和缺口冲击强度随玻纤含量的增加而大幅度提高,最大分别增加了173%、186%和283%。通过扫描电镜观察到玻纤嵌入尼龙66基体中,与尼龙66形成了良好的界面黏结。     

乙二胺修饰的碳纳米管对环氧树脂力学性能的影响

利用乙二胺对多壁碳纳米管(MWNTs)进行化学修饰,并制备碳纳米管/环氧树脂复合材料,研究了乙二胺修饰的碳纳米管对碳纳米管/环氧树脂复合材料力学性能的影响。实验表明,碳纳米管经乙二胺修饰后,改善了它在环氧树脂中的分散性,提高了环氧树脂复合材料的力学性能。氨基化碳纳米管用量达1.0%时,复合材料的冲击强度、断裂伸长率、拉伸强度和弯曲强度分别较纯环氧树脂提高200%、275%、48%和30%。     

Biopolyamide hybrid composites for high performance applications

This study focuses on the performance characteristics of wood/short carbon fiber hybrid biopolyamide11 (PA11) composites. The composites were produced by melt‐compounding of the fibers with the polyamide via extrusion and injection molding. The results showed that mechanical properties, such as tensile and flexural strength and modulus of the wood fiber composites were significantly higher than the PA11 and hybridization with carbon fiber further enhanced the performance properties, as well as the thermal resistance of the composites. Compared to wood fiber composites (30% wood fiber), hybridization with carbon fiber (10% wood fiber and 20% carbon fiber) increased the tensile and flexural modulus by 168% and 142%, respectively. Izod impact strength of the hybrid composites exhibited a good improvement compared to wood fiber composites. Thermal properties and resistance to water absorption of the composites were improved by hybridization with carbon fiber. In overall, the study indicated that the developed hybrid composites are promising candidates for high performance applications, where high stiffness and thermal resistance are required. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43595.     

Preparation and properties of multi‐walled carbon nanotubes/carbon fiber/epoxy composites

Multi‐walled carbon nanotubes/carbon fiber (MWCNTs/CF) hybrid fillers are employed to prepare MWCNTs/CF/epoxy composites. Results reveal that a great improvement of the thermal conductivities of the epoxy composites with the addition of MWCNTs/CF hybrid fillers, and the thermal conductivity of the MWCNTs/CF/epoxy composites is 1.426 W/mK with 8 vol% treated MWCNTs/CF hybrid fillers (5 vol% MWCNTs + 3 vol% CF). Both the flexural and impact strength of the MWCNTs/CF/epoxy composites are increased firstly, but decreased with the excessive addition of MWCNTs. The flexural and impact strength of the MWCNTs/epoxy composites are optimal with 2 vol% MWCNTs. For a given MWCNTs/CF hybrid fillers loading, the surface treatment of MWCNTs/CF hybrid fillers can further increase the thermal conductivities and mechanical properties of the MWCNTs/CF/epoxy composites. POLYM. COMPOS., 35:2150–2153, 2014. © 2014 Society of Plastics Engineers     

碳纳米管添加量对环氧树脂基复合材料性能的影响

采用模具浇铸法,通过对多壁纳米碳管(MWCNTs)进行表面官能化,制备了MWCNTs/环氧树脂复合材料。使用TEM、SEM、HRSEM和万能材料拉伸机对材料的结构和性能进行了测试和表征,并分析了微观结构与性能之间的关系。结果表明:当MWCNTS的添加量达到8%时,复合材料的综合性能达到最佳,拉伸强度和断裂伸长率分别提高13%和127.8%。     

PPS/PA66/HNTs复合材料的制备与性能研究

采用熔融共混方法制备了聚苯硫醚(PPS)/尼龙-66(PA66)/埃洛石纳米管(HNTs)复合材料,研究了其力学性能、热性能及其微观形态.结果表明:当PPS/PA66的比为60/40、HNTs的含量为30%时,复合材料具有较好的性能.复合材料的拉伸强度、弯曲模量及缺口抗冲击强度相对纯PPS分别提高了36.6%、163....     

Mechanical properties of carbon fiber reinforced bisphenol A dicyanate ester composites modified with multiwalled carbon nanotubes

A novel electrophoretic deposition (EPD) method was employed for grafting multiwalled carbon nanotubes (MWCNTs) on carbon fibers, which, after impregnation with bisphenol A dicyanate ester (BADCy), synergistically reinforced BADCy matrix composites (CNT‐C/BADCy). The effect of MWCNT presence on the mechanical properties of the composites was investigated. Composite tensile strength increased by 45.2% for an EPD duration of 2 min, while flexural strength exhibited a decreasing trend with EPD duration. Optical microscopy revealed that the existence of MWCNTs enhanced the fiber‐matrix interface while a large number of CNTs were observed to have pulled‐out from the matrix, a finding which explained the observed tensile strength increase in terms of energy dissipation by the specific toughening mechanism. The flexural strength decrease of the composites with CNTs as compared to specimens without nanotubes was found linked to the increased stress concentration in the BADCy matrix due to tube presence which weakens the adhesion between carbon fabrics. In a word, carbon nanotubes will enhance the micro interface and weaken the macro interface of the composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45100.