PA6／碳纳米管复合材料的复合方法的研究

ＣＶＤ法生产的碳纳米管经处理后呈纳米级分散，且表面产生大量的－ＯＨ官能团。碳纳米管与ＰＡ６（尼龙６）复合时，将通过其表面的－ＯＨ参加ＰＡ６的聚合反应，并阻碍ＰＡ６分子链的长大，削弱基体的强度。选择适当的复合方法，在尽量减少碳纳米管对ＰＡ６分子长大阻碍的基础上，改善碳纳米管在基体ＰＡ６中的分散，并进行后处理，可获得机能性能较好的ＰＡ６／碳纳米管复合材料。     

紫外线辐照HDPE与尼龙－6相容性的研究

采用ＩＲ、ＳＥＭ、ＤＳＣ和拉伸应力－应变曲线研究了紫外线辐照ＨＤＰＥ／ＰＡ６的相容性，结果表明，随紫外线辐照时间的增长，ＨＤＰＥ分子链上引入Ｃ＝Ｏ－Ｃ－Ｏ－等极性基团明显增加；ＰＡ６的粒径减小，与基体间界面作用加强；两组分玻璃化温度差（Ｔ_（ｇ，ＰＡ６）－Ｔ_（ｇ，ＨＤＰＥ））减小；共混物拉伸应力－应变曲线上出现屈服点及拉伸冷流塑性形变。当辐照时间达１４４ｈ后，由于ＨＤＰＥ热稳定性明显变差，共混物韧性突降，拉伸应力－应变曲线上未出现屈服点。     

力化学方法制备PP—g—HMA增容PA6／PP／硅灰石复合材料的形？…

以力化学方法制备的Ｎ－羟甲基丙烯酰胺接枝聚丙烯（ＰＰ－ｇ－ＨＭＡ）作尼龙６（ＰＡ６）／聚丙烯（ＰＰ）共混体系的增容剂,将增容尼龙６／聚丙烯共混体系与硅灰石复合。研究了复合材料的形态结构、硅灰石用量、偶联剂种类和用量以及增容剂等对复合材料的力学性能的影响。结果表明,ＰＰ－ｇ－ＨＭＡ能提高ＰＡ６／ＰＰ／硅灰石复合材料的力学性能,而ＫＨ－５５０和ＯＮ－３３０两种偶联剂复配使用则可以显著提高ＰＰ－ｇ－ＨＭ     

PP/PA6原位成纤复合材料 I.形态与力学性能

不相容的通用热塑性塑料聚丙烯（ＰＰ）和尼龙６（ＰＡ６）共熔挤出，当ＰＡ６为分散相时，得到了ＰＡ６纤维分散于ＰＰ基体中的原位复合材料。在ＰＰ和ＰＡ６的熔点之间成型，可以保持住纤维的形态。材料的拉伸强度下降，但冲击强度得到大幅度提高。     

基体含量对2D炭／炭复合材料性能影响的研究

研究了２Ｄ炭／炭毛坯－炭／酚醛（Ｃ／Ｐ）的基体含量对２Ｄ－Ｃ／Ｃ层间剪切性能的影响和防分层作用。结果表明,炭化后２Ｄ－Ｃ／Ｃ、致密２Ｄ－Ｃ／Ｃ的层剪强度都随Ｃ／Ｐ基体含量的增大而线性增加,而拉伸性能不受此影响。Ｃ／Ｐ基体含量影响２Ｄ－Ｃ／Ｃ的分层,基体含量低,ＩＬＳＳ低,难以抵抗热应力而发生分层。最终２Ｄ－Ｃ／Ｃ的ＩＬＳＳ在１３－１６ＭＰａ之间,拉伸强度在１３０－１８０ＭＰａ之间,拉伸模量在６８－     

真空蒸发沉积聚苯胺—TCNQ复合薄膜的STM研究

利用扫描隧道显微镜对真空蒸发沉积的聚苯胺－ＴＣＮＱ（ＰＡＮＩ－ＴＣＮＱ）复合薄膜、纯聚苯胺薄膜及纯ＴＣＮＱ薄膜试样进行了对比分析。研究发现,纯ＰＡＮＩ薄膜和纯ＴＣＮＱ薄膜都是绝缘膜,而用ＴＣＮＱ挽杂获得具有较高导电特性的ＰＡＮＩ－ＴＣＮＱ复合薄膜。而且与表面粗糙不连续的ＰＡＮＩ薄膜和ＴＣＮＱ薄膜相比,ＰＡＮＩ－ＴＣＮＱ复合薄膜易形成较大面积的表面结构完善的连续膜。傅里叶变换红外光谱（ＦＴＩＲ）分析     

EVA-g-MAH对PA6/EVA共混合金原位反应增容作用的研究

用乙烯－醋酸乙烯酯共聚物（ＥＶＡ）对尼龙６（ＰＡ６）进行增韧,加入乙烯－醋酸乙烯酯共聚物与马来酸酐的接枝物（ＥＶＡ－ｇ－ＭＡＨ）进行原位反应增容,在反应型双螺杆挤出机上实现反应增容共混过程,制备出了具有超韧性的ＰＡ６／ＥＶＡ／ＥＶＡ－ｇ－ＭＡＨ三元共混合金。探讨了ＥＶＡ－ｇ－ＭＡＨ对ＰＡ６／ＥＶＡ的原位反应及增容机理,用倍高扫描电镜考察了合金材料的亚微相态。结果表明,ＥＶＡ－ｇ－ＭＡＨ的加入使合金     

原位复合法复合PA6/巴基管复合材料的试验研究

经过硝酸处理的利用ＣＶＤ法生产的巴基管与ＰＡ６采用原位复合法进行复合时，将以其外壁上联结的羟基－ＯＨ和羧基－ＣＯＯＨ参与己内酰胺合成ＰＡ６的缩水聚合反应，从而结合到ＰＡ６的网状大分子结构中，同时也阻止ＰＡ６分子长大，并产生较大应力。     

通过分子复合和增塑制备新型高分子固体电解质

利用（甲基丙烯酸甲酯－甲基丙烯酸）共聚物［Ｐ（ＭＭＡ－ＭＡＡ）］与聚氧化乙烯（ＰＥＯ）的分子间氢键复合抑制ＰＥＯ的结晶，分子复合形成的独特超分子结构赋予材料优良的力学性和成膜性，在此基础上通过增塑进一步提高ＰＥＯ链段的活动性和锂盐在体系中的溶解性，制备出室温电导率达８．３１×１０~（－５）Ｓ·ｃｍ~（－１）、成膜性优良、实用价值较高的高分子固体电解质Ｐ（ＭＭＡ－ＷＡＡ）／ＰＥＯ／Ａ_２Ｌ_１ＣｌＯ_４。     

等离子喷涂制备HA/ZrO2复合涂层

采用等离子喷涂技术,在Ｔｉ－６Ａｌ－４Ｖ基体上成功地制备了羟基磷灰石／氧化锆（ＨＡ／ＺｒＯ２）复合涂层,对涂层的微观结构,相组成和结合强度进行了研究,并以模拟体液试验评估涂层的生物活性,结果表明,复合涂层较有较为微观结构,ＨＡ／ＺｒＯ２复合涂层的结合强度明显高于ＨＡ涂层,ＨＡ／６０ｗｔ％ＺｒＯ２涂层的结合强度高达２８．５ＭＰａ,为ＨＡ涂层的２．２倍,复合涂层在模拟体液中浸泡一段时间后,表面覆盖一层     

Mechanical characterization of epoxy composite with multiscale reinforcements: Carbon nanotubes and short carbon fibers

Carbon nanotubes (CNT) and short carbon fibers were incorporated into an epoxy matrix to fabricate a high performance multiscale composite. To improve the stress transfer between epoxy and carbon fibers, CNT were also grown on fibers through chemical vapor deposition (CVD) method to produce CNT grown short carbon fibers (CSCF). Mechanical characterization of composites was performed to investigate the synergy effects of CNT and CSCF in the epoxy matrix. The multiscale composites revealed significant improvement in elastic and storage modulus, strength as well as impact resistance in comparison to CNT–epoxy or CSCF–epoxy composites. An optimum content of CNT was found which provided the maximum stiffness and strength. The synergic reinforcing effects of combined fillers were analyzed on the fracture surface of composites through optical and scanning electron microscopy (SEM).     

Preparation and Thermal Properties of Grafted CNTs Composites

Oleylamine(G18) and octanol(G8) were grafted onto the surfaces of the multi-walled carbon nanotubes(CNTs).The grafted CNTs were dispersed into palmitic acid(PA) and paraffin wax(PW) to prepare phase change composites.The heat storage/retrieval experiments showed that the composites kept stable after repeating melting and solidification for 80 times.The structure of the G18-CNT/PA and G8-CNT/PA was homogenous compared with the pristine CNT(P-CNT)/PA.The latent heat capacity(Ls) of solid liquid phase change of G18-CNT/PW was higher than that of PW while those of the G8-CNT/PW and P-CNT/PW were lower than that of PW.Compared with PA,all PA based composites with both P-CNTs and grafted CNTs decreased Ls evidently.The Ls values of G18-CNT composites in both matrices were higher than that of the counterparts of G8-CNT.The thermal conductivities of all the PA based composites in the study were higher than that of PA,as well as those of all the PW based composites.However,the thermal conductivities of the G18-CNT composites in both matrixes were lower than those of the G8-CNT composites in both matrixes at all measured temperatures.     

碳纳米管增强PA6纤维的性能

将碳纳米管(CNT)在分散剂或分散剂和聚合物(PA6)载体中处理后制备出两种母粒,将其作为增强材料分别和PA6切片熔融共混纺丝,制备出碳纳米管的增强PA6纤维,研究其结构和力学性能.CNT含量低于0.5%(质量分数)时,使用两种母粒制备出的纤维强度和模量都提高,NT含量为0.03%时增强的效果最好.由碳纳米管和分散剂组成的母粒增强效果更好,NT的含量为0.03%时就能使PA6纤维的强度和模量分别提高23%和76%.这种增强纤维是一种微纤增强纤维,纳米CNT在纤维中均匀分散且沿着纤维轴的方向取向.这种结构能有效地转移载荷,具有增强作用,且取向性越好,增强效果越好.     

Al/CNT nanocomposite fabrication on the different property of raw material using a planetary ball mill

In recent years, significant research has been focused on the development of carbon nanotube (CNT) reinforced aluminum nanocomposites, which are quickly emerging because of their lightweight, high strength and other mechanical properties. The potential applications of these composites include the automotive and aerospace industries. In this study, powder metallurgy techniques are employed to fabricate aluminum (Al)/CNT nanocomposites with different raw material properties with optimized conditions. We successfully fabricated three different samples, including un-milled Al, un-milled Al with CNT and milled Al with CNT nanocomposites, in the presence of additional CNTs with various experimental conditions using a planetary ball mill. Scanning electron microscopy and field emission scanning electron microscopy are used to evaluate the particle morphology and CNT dispersion. The CNTs are well dispersed on the surface of the fabricated milled Al with CNT nanocomposites than un-milled Al with CNT nanocomposites for milling. The fabricated Al/CNT nanocomposites are processed by a compacting, sintering and rolling process. Vickers hardness measurements are used to characterize the mechanical properties. The hardness of the Al/CNT nanocomposites are improved milled Al with CNT nanocomposite compared other fabricated composites.     

球磨工艺对原位合成碳纳米管增强铝基复合材料微观组织和力学性能的影响

将原位化学气相沉积法合成的碳纳米管(CNTs)与铝的复合粉末进行球磨混合,进而粉末冶金制备CNTs/Al复合材料,研究球磨工艺对复合材料的微观组织和力学性能的影响。结果表明:球磨过程中不添加过程控制剂所得到的复合材料力学性能优异;随着球磨时间的增加,CNTs逐步分散嵌入铝基体内部,复合材料的组织也变得更加致密均匀。CNTs/Al复合材料的硬度和抗拉强度均随球磨时间的延长持续增加,但是伸长率先增后减。经90min球磨的CNTs/Al复合材料展现了强韧兼备的特点,其硬度和抗拉强度较原始纯铝提高了1.4倍和1.7倍,并且具有17.9%的高伸长率。     

Friction and wear behavior of carbon nanotubes reinforced polyamide 6 composites under dry sliding and water lubricated condition

The friction and wear behavior of carbon nanotube reinforced polyamide 6 (PA6/CNT) composites under dry sliding and water lubricated condition was comparatively investigated using a pin-on-disc wear tester at different normal loads. The morphologies of the worn surfaces and counterfaces of the composites were also observed with scanning electron microscopy (SEM). The results showed that CNTs could improve the wear resistance and reduce the friction coefficient of PA6 considerably under both sliding conditions, due to the effective reinforcing and self-lubricating effects of CNTs on the PA6 matrix. The composites exhibited lower friction coefficient and higher wear rate under water lubricated condition than under dry sliding. Although the cooling and boundary lubrication effect of the water contributed to reduce the friction coefficient of the composites, the adsorbed water lowered the strength of the composites and also inhibited the formation of transfer layers on the counterfaces resulting in less wear resistance. With the increasing normal loads, the friction coefficient of the composites increased under the dry sliding and decreased under the water lubricated condition, owing to inconsistent influences of shear strength and real contact areas. The specific wear rate of the composites increased under both sliding conditions.     

Effect of fiber diameter on the deformation behavior of self-assembled carbon nanotube reinforced electrospun Polyamide 6,6 fibers

High precision electrospinning technique was used to obtain self-assembled carbon nano-tube (CNT) reinforced polyamide (PA) 6,6 fibers. The reinforcement factors were critically evaluated with respect to the effects of fiber diameter and inclusion of CNTs. The average fiber diameter ranged from 240 to 1400 nm and the CNT contents were 0, 1 and 2.5 wt%. A sharp increase in modulus and strength of the fibers was demonstrated when the size of the fiber was decreased below ∼500 nm, which could be attributed to ordered arrangement of crystals and the spatial confinement effect of the fibers. Also, investigation of the deformation behavior of fibers as a function of CNT content revealed that tensile fiber modulus and strength improved significantly with increase of CNTs. Addition of CNTs restricted the segmental motion of polymer chains and provided the confinement effect to the neighboring molecules.     

快速固化碳纳米管/苎麻纤维/环氧树脂复合材料层板的制备与性能

针对植物纤维/树脂基复合材料高性能化问题,本研究以羟基化碳纳米管/无水乙醇分散液预先浸渍苎麻纤维织物,得到了碳纳米管分散均匀的碳纳米管/苎麻纤维多尺度复合织物,并进一步以快速固化环氧树脂为基体,采用真空辅助树脂灌注成型工艺(VARI)制备了碳纳米管改性的苎麻纤维/环氧树脂基复合材料层板(PRFC)。研究结果表明,相比未采用碳纳米管改性的苎麻纤维/环氧树脂复合材料(RFC),PRFC的弯曲强度提高14.7%,冲击强度提高20.9%。相比碳纳米管预先分散于环氧树脂基体中制备的碳纳米管改性苎麻纤维/环氧树脂复合材料(MRFC),PRFC的力学性能提高更显著。同时,PRFC的吸湿性能比MRFC和RFC的明显降低。     

Combination effect of physical drying with chemical characteristic of carbon nanotubes on through-thickness properties of carbon fiber/epoxy composites

The present work studied the combination effect of physical drying with chemical modification of carbon nanotubes (CNTs) on some through-thickness properties of carbon fiber/epoxy composites. Different drying methods of heat drying and freeze drying were utilized to affect CNT organization form in carbon fiber/CNTs preforms and composites: The adoption of heat-drying method made CNTs more inclined to form aggregates accompanied with randomly scattered CNTs, while continuous CNT networks could always be assembled when freeze drying method was employed. The formation mechanism of such CNT networks was discussed, and could be described as “freeze drying within confined space.” Chemical characteristic of CNTs was controlled by choosing different solutions of non-functionalized CNTs (NOCNTs) or hydroxyl-modified CNTs (OHCNTs). As a consequence, CNT networks modified composites, especially that with OHCNTs formed networks, displayed significantly better electrical performance than composites with CNT aggregates and scattered CNTs; NOCNT networks and scattered OHCNTs made the corresponding composites possess higher interlaminar shear strength (ILSS) value, whereas OHCNT networks impaired ILSS while enhancing flexural strength and modulus of composites.