聚丙烯/聚苯硫醚原位微纤共混物的结构与性能

用熔融挤出拉伸冷却方法制备了聚丙烯/聚苯硫醚原位微纤共混物,研究了其形态、结晶形态、热性能、硬度和动态力学性能。发现PPS在基体中形成良好的微纤形态,并且在共混物中发现有球晶。DSC曲线中可以看出,聚丙烯的熔融温度没有大的变化,PP的起始结晶温度随着PPS含量的增加而提高。PP/PPS共混物的热变形温度随着PPS含量的增加不断提高。硬度测试结果表明,PPS的加入使得共混物的硬度增加。DMA曲线显示当温度到达一定程度的时候,tanδ有最大值;随着温度的升高,PP/PPS共混物的损耗模量不断降低;共混物的储能模量随着温度的提高而降低。     

表面处理碳纤维对增强尼龙复合材料性能影响

采用空气氧化法对碳纤维进行表面处理 ,以注塑成型法制备碳纤维增强尼龙 1 0 1 0复合材料 .研究发现表面处理碳纤维可明显提高增强尼龙复合材料的拉伸强度和摩擦学性能 ,其中摩擦系数较未处理碳纤维增强降低了 3 0 %～ 5 0 % ,而耐磨性提高了 2～ 3倍 .用扫描电镜对拉伸断口和磨损表面形貌分析发现 ,表面处理可显著改善碳纤维和尼龙基体间的界面结合性能 .最后对影响表面处理碳纤维增强复合材料性能的作用机理进行了初步分析     

Mechanical Properties of Phenolic-Resin Composites Reinforced with CF/BF Interlayer Hybrid Fibers

Phenolic-resin composites reinforced with carbon fiber (CF) and basalt fiber (BF) interlayer hybrid fibers plain fabric were fabricated. The tensile strength, compressive strength and interlaminar shear strength of the prepared composites were studied. The results indicated that hybrid fibers reinforced composites possessed the advantages of both CF and BF. When resin content was 35% by volume fraction, the comprehensive mechanical performance of BF/CF reinforced phenolic resin composites reached the optimal values with the warp and weft direction tensile strength, compressive strength and interlayer shear strength being 252 MPa and 487 MPa, 105 MPa and 129 MPa, 21 MPa and 20 MPa, respectively. The scanning electron microscope (SEM) observations showed that the BF/CF hybrid fibers reinforced composites had better interfacial adhesion.     

全金属组元铁基块体非晶的制备与性能研究

3D打印成型碳纤维接枝碳纳米管增强热塑性复合材料的强度提高

王婼楠¹，吴海宏^1，2，郭子月³，刘春太²，申长雨²

（1. 河南工业大学 机电工程学院，郑州450001; 2.郑州大学 橡塑模具国家工程研究中心，郑州450002; 3.中山大学 数学学院（珠海）,珠海519082）

创新点说明：

1) 研究了碳纤维定量接枝碳纳米管对热塑性复合材料的界面性能及拉伸性能的影响。

2) 用3D打印模压成型的工艺方法制备了热塑性复合材料。

研究目的：

研究碳纤维表面接枝不同含量的碳纳米管对复合材料微观结构、界面性能和力学性能的影响。

研究方法：

1) 采用溶液法，通过控制碳纳米管接枝反应时间，制备不同含量碳纳米管接枝碳纤维，然后用硝酸刻蚀法，去除残留溶剂，验证了碳纳米管接枝的可靠性。用扫描电镜观察碳纤维的微观形貌，用FTIR测试碳纤维表面官能团并用XPS对碳纤维的表面官能团进行分析。

2) 用扫描电镜观察碳纤维与基体的结合情况并用接触角测量仪测试碳纤维与基体的接触角。

3) 通过 3D打印成型法成型了热塑性复合材料样条，并用扫描电镜观察碳纤维热塑性复合材料的界面微观形貌。

4) 采用万能试验机测试3D打印成型热塑性碳纤维复合材料的拉伸性能，并观察复合材料断口形貌。

结果：

1) 溶液法.扫描电镜观察发现碳纳米管在碳纤维表面均匀分布，表明碳纤维与碳纳米管之间存在较强的键合关系。但随着接枝时间的增加，碳纤维表面的碳纳米管含量逐渐增加，但达到0.4%时，出现分散不均匀现象。碳纤维表面含有上浆剂和去掉上浆剂的对比发现，无上浆剂的碳纤维表面沟壑明显，这些沟槽可以增加碳纤维的比表面积和表面能，增强了基体与碳纤维的机械相互作用。用FTIR测试碳纤维表面官能团并用XPS对碳纤维的表面官能团进行分析，结果表明，经偶联剂改性后，C=O键含量明显增加，碳纤维表面引入含氧官能团。C1，O1S峰增强，表明碳纳米管接枝到了碳纤维表面。

2) 扫描电镜结果表明，与表面未接枝碳纳米管的碳纤维相比，接枝碳纳米管的碳纤维与基体PA6具有更好的润湿性。接触角测试结果对比发现，接枝碳纳米管的碳纤维与基体的接触角，明显小于未接枝碳纳米管的。

3) 通过扫描电镜观察复合材料的界面微观形貌，结果表明：纤维与基体之间存在一定厚度的界面层，界面层的存在可以减轻纤维与基体之间的力学性能突变引起的应力集中，并防止界面缺陷的扩展。

4）界面结合强度测试结果表明，当碳纳米管的质量分数增加到0.25%时，复合材料的界面结合强度比未接枝碳纳米管的碳纤维增强的PA6复合材料提高了20%，比表面有环氧的碳纤维复合材料提高了41.8%。然而当碳纳米管含量大于0.4%时，界面结合强度不再继续增加。力学测试表明碳纳米管含量为0.25%的复合材料具有最高的平均模量、拉伸强度和界面剪切强度。接枝碳纳米管的碳纤维复合材料断口形貌可以观察到界面处基体中的韧窝。表明基体树脂在拔出纤维前经历了较大的塑性变形，表明纤维与基体有很好结合性。

结论：

实验结果表明，碳纳米管可以提高表面的润湿性和CF表面粗糙度。碳纳米管接枝碳纤维增强PA6与环氧上浆的碳纤维复合材料相比，当碳纳米管的质量分数达到0.25%时，复合材料的界面结合强度增加了41.8%，拉伸强度提高了130%，界面剪切强度提高了238%。然而，随着碳纳米管含量的继续增加到0.4%时，界面结合强度和力学性能就会下降。

关键词：热塑性复合材料，界面结合强度，界面剪切强度，3D打印成型

     

碳纤维水泥基复合材料电阻变化规律研究

研究了碳纤维水泥基复合材料在水化期间及固化后的电阻变化特性。研究发现：当碳纤维体积分数较低时，试样的电阻率随着固化时间的增大而明显增大；反之，当碳纤维体积分数超过某一个范围后，会出现电阻（率）随水化时间的延长而变小的规律。此外，对于已固化好的碳纤维水泥基复合材料，随着电流（电压）的增大，电阻会出现一定程度的降低，碳纤维体积分数越低（即电阻率越大时），电阻下降的趋势越明显。     

Dynamic mechanical properties of PTFE-based composites filled with multi-component

To improve performance of PTFE-based damping material,composites with several fillers were prepared by compressing and sintering. The dynamic mechanical properties of the composites were investigated by means of viscoanalyser. Temperature-dependent loss factors,storage modulus and loss modulus were obtained. And SEM was employed to study the compatibility between PTFE and fillers. The results show that,when blending PPS and PEEK at proper content,the loss factor curve appears double peaks,which can widen the high-damping temperature region of the composites. Blending graphite or alumina can increase the storage modulus obviously,but decrease the value of loss factor. And because graphite or alumina combines with matrix poorly,glide would happen at interface when bearing external load. The interface friction can dissipate vibration energy,which increases the loss modulus of the composites. Blending PPS,PEEK and graphite or alumina at right content,PTFE-based composites can meet demands as damping material in practical engineering.     

Electrical resistance behavior of vinylester composites filled with glass-carbon hybrid fibers

Vinylester (bismethacryloxy derivative of a bisphenol-A type EP resin, VE) composites with glass-carbon hybrid fibers (CF-GF) weight fraction of 50%, were prepared by the compress molding method. The distribution of carbon fiber in the hybrids was observed by stereomicroscope. The electrical resistance behavior of the composites filled with different carbon fiber (CF) weight contents (0.5% to 20%) was studied. The experimental results show that the electrical resistance behaviors of CF-GF/VE composites are different with those of CF/VE composites because carbon fibers’ conducting networks are broken by the glass fibers in the CF-GF/VE composites. The carbon fibers distribute uniformly in the networks of glass fibers (GF) like single silk and form the semi-continuous conducting networks. Composite filled with GF-CF hybrid has a higher percolation threshold than that filled with pure CF. At that time, the resistivity of CF-GF/VE composites varies little with the temperature increasing. The temperature coefficient of resistivity in GF-CF/VE composite is less than 317 ppm and the variation of the resistivity after ten thermal cycles from 20 °C to 240 °C is less than 1.96%. Funded by the Natural Science Foundation of Hubei Province (No. 2007ABA028)     

混合纤维对尼龙66的增刚研究

以尼龙66（PA66）为基体,研究和分析玻璃纤维和碳纤维混杂对尼龙66增刚的影响.固定玻璃纤维质量分数为24.6%,改变碳纤维的质量分数,将玻璃纤维（GF）、碳纤维（CF）先用硅烷偶联剂KH550进行表面处理,用双螺杆挤出造粒和注塑成型方式制备GF/CF增刚PA66复合材料,对试样进行拉伸模量、拉伸强度、弯曲模量、弯曲强度、缺口冲击强度等性能测试,并利用扫描电镜分析复合体系的冲击断面特征.研究结果表明：GF/CF混合纤维对PA66具有很好的增刚效果.     

In situ construction of BiVO4(-)cellulose fibers@CDs(-)polyvinyl alcohol composites for tetracycline photocatalytic degradation

Non-biodegradable and toxic photocatalysts pose as secondary threats to the environmental security. In this work, non-toxic biocomposites were prepared using natural bamboo cellulose fibers(CF), polyvinyl alcohols(PVAs), BiVO_4, and carbon dots(CDs) from biomaterials. Thereafter, their optical properties, chemical characterizations, and photocatalytic performances were evaluated. The novel BiVO_4(-)CF@CDs(-)PVA composites were prepared via the combined implementation of in situ and impregnation methods. The optical properties revealed that the CDs and fibers increased the range and intensity of light absorption. The PVAs were used as the shield and dispersant to enhance stability because they have numerous chemical groups.In view of the various possible paths of electron migration, the enhanced photocatalytic activity of BiVO_4(-)CF@CDs(-)PVA composites for tetracycline degradation was observed under visible light illumination. The origins of the structure, morphology,and optical mechanism in the enhancement of the photocatalytic ability of BiVO_4(-)CF@CDs(-)PVA composites were discussed and demonstrated.     

Effect of nano-silica modification on the tensile property of SMA/GF/CF/epoxy super hybrid woven fabric composites

Tensile properties of epoxy casts together with shape memory alloy (SMA), glass (GF) and carbon (CF) woven fabric reinforced epoxy matrix super hybrid composites were investigated, respectively. In order to enhance the mechanical strength of this advanced material, two categories of modifications including matrix blending and fiber surface coating by nano-silica were studied. Scanning electron microscopy (SEM) and fiber pull-out tests were adopted to complement the experimental results, respectively. Experimental results reveal that the toughness of epoxy matrix is enhanced significantly by adding 2wt% nano-silica. The failure mechanism of SMA reinforced hybrid composites is different from that of GF/CF/epoxy composites. Compared with the matrix modification, the fibers modified by coating nano-silica on the surface have better tensile performances. Moreover, the fiber pull-out test results also indicate that composites with fiber surface modification have better interfacial performances. The modification method used in this paper can help to enhance the tensile performance of the mentioned composite materials in real engineering fields.     

碳纤维上电聚合噻吩对复合材料性能的影响

为了改善碳纤维与树脂基体之间的界面性能,以噻吩为单体,采用循环伏安法对碳纤维进行电化学聚合改性.利用扫描电子显微镜研究了电化学聚合改性前后碳纤维的表面结构变化,采用电脑伺服控制材料试验机测试了碳纤维增强环氧树脂复合材料的力学性能.结果表明,当噻吩浓度为0.4 mol/L时,峰值电流增加幅度最大,电聚合效果最佳.当循环次数达到60次时,碳纤维表面电化学聚合反应完全,碳纤维/环氧树脂复合材料的层间剪切强度可由13.46 MPa增加到23.79 MPa,提高约76.75%.电化学聚合后大量片层状聚噻吩聚合物在碳纤维表面聚集,碳纤维与环氧树脂基体紧密结合,界面性能明显提高.     

制备工艺对CNTs/EP复合材料性能的影响

采用溶液共混法制备碳纳米管(CNTs)/环氧树脂(EP)复合材料,主要研究丙酮用量、混合方式、超声时间、CNTs含量等制备工艺对复合材料的热性能和导电性能的影响.通过用SEM、DSC,TGA以及万用表对复合材料进行分析表征,结果表明,丙酮的加入量越多,超声时间越长,CNTs/EP的复合材料的导电性越好,CNTs在复合材料中分散性也好,而随着CNTs含量增加,复合材料的导电性按照逾渗理论的规律提高,且逾渗闶值出现在0.5 0A～1%范围内.利用超声处理伴随着搅拌这种混合方式所得复合材料的导电性最好,加入碳纳米管的复合材料玻璃转化温度Tg和热稳定性能较纯EP有显著提高.     

表面涂层对碳纤维的强度和断裂特征的影响

利用化学气相沉积法在碳纤维表面获得了ＳｉＣ，Ｃ＋ＳｉＣ，Ｓｉ，Ｃ－Ｓｉ梯度等多种涂层，研究了各种涂层对碳纤维强度的影响，分析了涂层碳纤维的断裂过程与断口形貌，实验结果显示：Ｃ－Ｓｉ梯度涂层碳纤维具有较高的抗拉强度，这是任何单一涂层所无法比抉的。另外，单Ｓｉ涂层碳纤维的断口为拨出型，其它几种涂层碳纤维的断口为平切型。     

Mechanical Properties Amelioration of Hybrid Composites by Concomitant Synergy Between Graphene Oxide and Silica Nanoparticles

氧化石墨烯和二氧化硅纳米颗粒协同作用下的

复合材料力学性能改善

Anchalee Duongthipthewa, 杨树明*,王一鸣

（西安交通大学 机械制造系统工程国家重点实验室,西安 710049）

创新点说明：

本文提出将氧化石墨烯和纳米二氧化硅颗粒组成的纳米复合材料作为填充物添加到环氧树脂/碳纤维复合材料体系中,用于提升其机械性能和湿润环境下的抗腐蚀性。

研究目的：

通过实验研究了氧化石墨烯和纳米二氧化硅颗粒组成的纳米复合材料作为填充物对环氧树脂/碳纤维复合材料体系的机械性能增强作用,以及在湿润环境下的抗腐蚀性。

研究方法：

本文通过真空辅助树脂传递模塑（VARTM）方法制备了环氧树脂/碳纤维复合材料样品,同时也通过该方法向复合材料体系中添加了不同分量的氧化石墨烯和纳米二氧化硅颗粒组成的纳米复合填料;通过三点弯曲测试、冲击实验、硬度测试和动态力学分析等方法对所制备样品的弯曲强度、冲击强度、硬度等机械性能进行了测量;通过分别在纯水和盐水中浸泡2周,对样品的吸湿性、烘干后的重量保留和性能保留进行了分析测试。

结果：

实验结果表明,对于添加了氧化石墨烯和纳米二氧化硅颗粒组成的纳米复合材料作为填充物的环氧树脂/碳纤维复合材料体系,其机械性能表现出全面的明显提升,包括弯曲强度、冲击强度、硬度等;纳米二氧化硅分量的提高还会使其性能得到进一步提升;对于含有复合纳米填充物的样品,其暴露在湿润环境中时虽然吸湿度较高,但烘干后重量损失反而较小,而且再次对其机械性能进行测试后发现其性能保留程度也较高;同样的,含有高分量纳米二氧化硅的样品性能表现最优。为探究其增强原理,通过扫描电子显微镜对样品断面进行了分析。

结论：

实验结果显示,复合填充物的存在使整个复合材料体系的机械强度得到提升,其根本原因在于复合填充材料的存在使环氧树脂与碳纤维骨架的结合更加紧密,在收到外力作用时应力得以迅速传递避免累积,扫描电子显微镜的结果也支持该结论。

关键词：复合材料,纳米填充,机械性能,热分析,吸湿性

     

Influence of Water Content on Conductivity and Piezoresistivity of Cement-based Material with both Carbon Fiber and Carbon Black

The influence of water content on the conductivity and piezoresistivity of cement-based material with carbon fiber (CF) and carbon black (CB) was investigated. The piezoresistivity of cement-based material with both CF and CB was compared with that of cement-based material with CF only, and the changes in electrical resistivity of cement-based material with both CF and CB under static and loading conditions in different drying and soaking time were studied. It is found that the piezoresistivity of cement-ba...     

用有限元法对CF/PPEK热塑性复合材料等效模量计算

碳纤维增强杂萘联苯聚醚酮(CF/PPEK)是一种新型高性能热塑性复合材料.根据复合材料细观结构周期性假设,隔离出复合材料的代表性体积元———RVE(representative volume element).基于能量等效的原理,通过对RVE施加简便的边界载荷和恰当的边界条件,运用细观力学有限元法,采用有限元软件Ansys计算了复合材料的等效弹性模量.理论计算及试验结果表明该方法能够较好地预测此种复合材料的宏观弹性性能.     

碳纤维/膨胀石墨协同复合对硅橡胶性能的影响

采用溶液插层法制备了膨胀石墨(expanded graphite,EG)/硅橡胶(VMQ)导热复合材料,利用短切碳纤维(carbonfiber,CF)对复合材料体系进行增强.研究了EG、CF和钛酸酯偶联剂对硅橡胶导热和力学性能的影响.结果表明:短切CF与EG有良好的协同复合作用,一定量的钛酸酯偶联剂可以有效地改善填料与...     

超高性能钢纤维混凝土抗二次接触爆炸性能研究

采用复合技术制备了两种强度等级的超高性能钢纤维混凝土(UHPSFRC),对6块靶体进行了抗一次和抗二次接触爆炸试验,对比分析了靶体材料的抗爆炸性能.结果表明,制备的超高性能钢纤维混凝土具有优异的抗一次和抗二次爆炸性能.对压缩系数进行了计算分析,建议超高性能钢纤维混凝土(有粗骨料)CF150的压缩系数取为0.112,超高性能钢纤维混凝土(无粗骨料)CF200取为0.096,且CF200的抗二次爆炸压缩系数要降低到80%左右.     

3D打印多种形貌CF/ABS复合材料扳手

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