聚氨酯/碳纳米管复合材料的制备及表征

采用原位聚合法制备了聚氨酯/碳纳米管复合材料,并利用扫描电子显微镜、傅立叶红外光谱仪对其进行了表征,同时探讨了碳纳米管对复合材料力学性能、热稳定性、弹性回复率及导电性能的影响.结果表明,经过酸处理的碳纳米管参与了聚合反应,并在基体中获得了较好的分散,同时力学性能、热稳定性及导电性都有明显的提高,而弹性回复率没有受到很大的影响.     

碳纳米管改性方法对其与聚氨酯的复合材料性能的影响

通过强酸回流、强碱球磨方法分别对碳纳米管进行了改性处理,采用溶液共混法制备了聚氨酯/碳纳米管复合材料。探讨了碳纳米管改性方法对复合材料的化学结构、微观形态、力学性能、热稳定性能以及导电性能的影响。结果表明,在聚氨酯基体中添加经化学改性处理的碳纳米管使复合材料的氢键增多,力学性能、热稳定性和导电性能都得到了提高。聚氨酯/强碱球磨处理碳纳米管复合材料中的氢键数目更多,综合性能也更优异,而且碳纳米管在聚氨酯基体中的分散更均匀。     

制备方法对聚氨酯/碳纳米管复合材料性能的影响

对碳纳米管(CNTs)进行酸改性,采用溶液共混法和原位聚合法制备了聚氨酯(PU)/CNTs复合材料,考察了CNTs对复合材料力学性能、热稳定性能和弹性回复率的影响.结果表明,与PU相比,用该2种方法制备的PU/CNTs复合材料的力学性能和热稳定性能都有所提高,但用原位聚合法提高的程度较大,而制备方法对复合材料的弹性回复性影响不大.     

聚氨酯/碳纳米管复合材料的制备及其性能研究

通过强碱球磨方法对多壁碳纳米管(MWCNTs)进行了改性处理,并对其化学结构和微观形态进行了分析.采用溶液共混法制备了聚氨酯(PUR)/MWCNTs复合材料.利用扫描电子显微镜、傅立叶变换红外光谱仪对其进行了表征.探讨了MWCNTs对PUR/MWCNTs复合材料力学性能、热稳定性以及电导率的影响.结果表明,MWCNTs...     

原位聚合法制备热塑性聚氨酯/多壁碳纳米管复合材料及其性能研究

采用原位聚合法制备了热塑性聚氨酯/多壁碳纳米管(TPU/MWNT)复合材料,利用热重分析(TGA)、体积电阻率测试、维卡软化点测试、力学性能测试,研究了多壁碳纳米管(MWNT)质量分数对复合材料热稳定性、导电性以及力学性能的影响。结果表明,经酸化处理的MWNT可以显著提高复合材料的热稳定性和力学性能,质量分数为0.8%的TPU/MWNT复合材料具有最优异的热稳定性和力学性能。同时,一定含量的MWNT能够搭建三维网络结构,使材料的导电性和耐热性也得到了显著提高。     

PA66/胺基化碳纳米管复合材料薄膜的制备及表征

对多壁碳纳米管进行胺基化处理后,用溶液共混法制备了PA66/多壁碳纳米管复合材料,研究了碳纳米管的加入对PA66电学性能、热稳定性能、结晶行为的影响。复合材料薄膜的渗流阈值出现在碳纳米管质量分数为3%～4.5%,胺基化碳纳米管质量分数为4%时,已基本构成完整的导电网络,体积电阻率和表面电阻率均降低了8个数量级。碳纳米管的加入提高了复合材料的热稳定性能。碳纳米管在复合材料中充当了成核剂,提高了PA66的成核速度,但降低了其结晶总速度。     

改性纳米二氧化硅对聚乙烯的热性能及阻燃性能的影响

本文选择了3种经不同表面改性处理的纳米SiO2,采用热分析(TG)和红外光谱(FTIR)对聚乙烯/改性纳米SiO2复合材料的热稳定性能及结构变化进行了研究,并将其用于无卤阻燃聚乙烯体系,针对改性纳米SiO2对无卤阻燃聚乙烯阻燃性能和力学性能的影响进行了分析.研究结果表明,与未改性纳米SiO2相比,经改性处理的纳米SiO2有利于提高复合材料的热稳定性能,延缓聚乙烯的热氧化降解,经适当改性处理,可使纳米复合材料的热稳定性高于聚乙烯.FTIR结果证实二氧化硅主要发挥物理作用,改性方法对降解后体系结构影响不大.改性纳米SiO2显著提高了无卤阻燃聚乙烯的阻燃性能,在填料用量相同时,可获得力学性能和阻燃性能较佳的材料.     

聚合物/碳纳米管的研究进展

碳纳米管具有独特的结构，优异的力学性能、热稳定性与导电性能，与聚合物并用可开发出多种新型复合材料，评述利用直接混合法、原位聚合法与超声波处理法制备聚合物／碳纳米管材料，并讨论该复合材料的力学性能，光电性能与磨擦学性能。     

硅橡胶/多壁碳纳米管复合材料的结构与性能研究

研究了硅橡胶/多壁碳纳米管复合材料的形态结构和物理机械性能。利用扫描电子显微镜观测了复合材料中多壁碳纳米管的分散情况,并测试分析了复合材料的力学性能、热性能、动态力学性能。结果表明,多壁碳纳米管能够良好地分散在硅橡胶基体中,随着多壁碳纳米管用量的增加,硅橡胶/多壁碳纳米管复合材料热稳定性明显提高,且有效地提高了硅橡胶的物理机械性能。硅橡胶/多壁碳纳米管复合材料中形成了碳纳米管的某种形式网络结构,网络结构的打破与重建导致了储能模量的非线性下降。     

酸化多壁碳纳米管/水性聚氨酯复合材料的制备与性能研究

采用混酸对多壁碳纳米管进行表面处理,通过共混法制备出酸化多壁碳纳米管/水性聚氨酯(WPU)复合材料。通过FT-IR,拉曼光谱,SEM表征了多壁碳纳米管酸化前后的结构,通过TGA、拉力测试以及SEM研究了复合材料的热性能、力学性能和微观结构。结果显示,多壁碳纳米管通过混酸处理后表面羧基化,管壁卷曲程度降低。与纯WPU相比,当添加量为1.5%时,复合材料的断裂伸长率增加29%,当添加量在2%时,复合材料的拉伸强度增加169%,酸化碳纳米管在聚氨酯(PU)基体中均匀分散。酸化碳纳米管的添加显著提高了复合材料的热稳定性和导电性。     

聚丙烯/碳纳米管微孔注塑发泡行为及力学性能

研究了不同含量单壁碳纳米管(CNT)的加入对聚丙烯(PP)流变、热稳定性及微孔注塑发泡行为和力学性能的影响。结果表明，随着CNT含量从不足1.0 %(质量分数，下同)逐渐增加，PP熔体黏度显著增大，热稳定性逐渐提升，即使CNT的加入量仅为0.15 %也会产生团聚现象,但团聚体尺寸较小且与基体结合紧密；微孔发泡注塑样品中泡孔分布不均匀,泡孔尺寸范围在10~70 μm，直径随着CNT含量增加呈现先减小后增大；PP/CNT复合材料微孔发泡成型后，弹性模量、屈服应力下降不大，但断裂伸长率平均提升了近400 %，不同组分发泡样品间力学性能指标变化不大。     

Preparation and properties of hierarchical composites based on carbon nanotubes‐coated glass babric preform

A strategy based on carbon nanotubes (CNTs)‐containing sizing dispersion has been implemented to fabricate nanocomposite preforms and their hybrid multiscale composites. The state of pristine CNTs and carboxylic acid functionalized CNTs (CNTs–COOH) in sizing dispersion was effectively monitored by on‐line measuring electrical conductivity. The effects of different CNTs coating applied onto glass fabric on wettability of nanocomposite fibrous reinforcement with epoxy matrix were evaluated using scanning electron microscopy and capillary experiment. A CNTs‐COOH loading of 0.5 wt% gave rise to 97% and 30°C increases in the storage modulus (G′) and glass transition temperature of the resulting hybrid composites, respectively. The enhanced thermomechanical properties of the CNTs hybrid composites are closely related to the stable CNTs sizing dispersion and uniform coating onto fiber reinforcement. The mechanism for reinforcing composites through toughening resin region with CNTs desorbing from primary fiber surface during impregnation has been identified. POLYM. COMPOS. 37:979–986, 2016. © 2014 Society of Plastics Engineers     

Dispersion and thermal conductivity of carbon nanotube composites

A mechanical method was used to shorten carbon nanotubes (CNTs) for improving dispersion without reducing their thermal conductivity. Single walled carbon nanotubes (SWCNTs) were mechanically cut to produce short and open-ended fullerene pipes. These shortened SWCNTs were then used in polymer composites. Both atomic force microscopy and scanning electron microscopy characterizations suggested that nanotube shortening significantly improved CNT dispersion. Thermal conductivity of composites containing short CNTs were found to be much better than those containing pristine CNTs.     

Structure and properties of multiwalled carbon nanotubes/cyanate ester composites

Two types of multiwalled carbon nanotubes (MW‐CNTs) with different structure and morphology were used to fabricate cyanate ester (CE) matrix composites. Mechanical, thermal, and transmission electron microscopy tests were performed to evaluate the different effects of the two types of MW‐CNTs on the structure and properties of MW‐CNT/CE composites. Results showed that the bundled MW‐CNTs were easier to be dispersed in CE matrix than single MW‐CNTs, and could improve the toughness and stiffness of CE material more significantly. Functionalization of the two types of MW‐CNTs, which was achieved by grafting triethylenetetramine groups onto the surface of MW‐CNTs, was helpful in improving the dispersion of the MW‐CNTs in CE, and thus in fabricating MW‐CNT/CE composites with improved mechanical and thermal properties. POLYM. ENG. SCI. 46:670–679, 2006. © 2006 Society of Plastics Engineers     

Preparation of a functional reduced graphene oxide and carbon nanotube hybrid and its reinforcement effects on the properties of polyimide composites

The homogeneous dispersion and strong interfacial interactions of carbon nanomaterials are vital factors on enhancing the properties of polymer composites. Two‐dimensional reduced graphene oxide (rGO) and one‐dimensional carbon nanotubes (CNTs) were first grafted by 4,4′‐oxydianiline (ODA). The successful grafting of ODA onto the rGO and CNTs were confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and X‐ray photoelectron spectroscopy. The hybrid carbon nanomaterials of the functionalized CNTs and rGO with different ratios were prepared via a solution‐mixing method, and their dispersion state was investigated. The hybrid carbon nanomaterials with good stability were introduced to polyimide (PI) via in situ polymerization. The morphology and properties of the polymer composites were studied. The results show that much better mechanical and electrical properties of the composites could be achieved in comparison with those of the neat PI. An improvement of 100.7% on the tensile strength and eight orders for the electrical conductivity were achieved at only a 1.0 wt % hybrid content. A significant enhancement effect was attributed to the homogeneous dispersion of the filler, filler–matrix strong interfacial interactions, and unique structure of the hybrid carbon nanomaterials in the composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44575.     

改性碳纳米管增强热塑性聚氨酯复合材料的性能研究

以碳纳米管（CNTs）和热塑性聚氨酯（TPU）为原料,通过硫酸（H₂SO₄）/硝酸（HNO₃）混合溶液处理碳纳米管颗粒表面以达到改性的效果,使用改性过后的碳纳米管熔融共混制备出TPU/CNTs复合材料。研究了不同含量的CNTs对TPU基体的流变、力学、耐磨性以及热性能的影响。结果表明, 改性过后的CNTs在TPU基体中形成了良好的分散性和相容性;TPU/CNTs复合材料在高频剪切下保留了复合材料的加工流动性,并且复合材料的拉伸强度以及耐磨性相较于TPU有明显的增强,其中在改性碳纳米管含量较低时,复合材料的力学性能改善较为明显;改性CNTs的加入提高了TPU基体的熔融温度和结晶度;改性CNTs的加入提高了复合材料的热降解温度,提高了TPU基体的热稳定性。     

碳纳米管纳米复合材料的研究现状及问题

文章介绍了碳纳米管的结构和性能,综述了碳纳米管聚合物复合材料的制备方法及其聚合物结构复合材料和聚合物功能复合材料中的应用研究情况,在此基础上,分析了碳纳米管在复合材料制备过程中的纯化、分散、损伤和界面等问题,并展望了今后碳纳米管/聚合物复合材辩的发展趋势.     

Optimized process for the inclusion of carbon nanotubes in elastomers with improved thermal and mechanical properties

The effects of addition of reinforcing carbon nanotubes (CNTs) into hydrogenated nitrile–butadiene rubber (HNBR) matrix on the mechanical, dynamic viscoelastic, and permeability properties were studied in this investigation. Different techniques of incorporating nanotubes in HNBR were investigated in this research. The techniques considered were more suitable for industrial preparation of rubber composites. The nanotubes were modified with different surfactants and dispersion agents to improve the compatibility and adhesion of nanotubes on the HNBR matrix. The effects of the surface modification of the nanotubes on various properties were examined in detail. The amount of CNTs was varied from 2.5 to 10 phr in different formulations prepared to identify the optimum CNT levels. A detailed analysis was made to investigate the morphological structure and mechanical behavior at room temperature. The viscoelastic behavior of the nanotube filler elastomer was studied by dynamic mechanical thermal analysis (DMTA). Morphological analysis indicated a very good dispersion of the CNTs for a low nanotube loading of 3.5 phr. A significant improvement in the mechanical properties was observed with the addition of nanotubes. DMTA studies revealed an increase in the storage modulus and a reduction in the glass‐transition temperature after the incorporation of the nanotubes. Further, the HNBR/CNT nanocomposites were subjected to permeability studies. The studies showed a significant reduction in the permeability of nitrogen gas. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Incorporation of 4‐aminobenzene functionalized multi‐walled carbon nanotubes in polyaniline for application in formic acid electrooxidation

Incorporation of carbon nanotubes (CNTs) in conducting polymer can lead to new composites with enhanced electrical and mechanical properties. However, the development of such composites has been hampered by the inability to disperse CNTs in polymer matrix due to the lack of chemical compatibility between polymers and CNTs. Covalent sidewall functionalization of carbon nanotube provides a feasible route to incorporate carbon nanotube in polymer. In this work, 4‐aminobenzene groups were grafted onto the surface of multi‐walled carbon nanotube (MWNT) via C? C covalent bond. Polyaniline (PANI)/MWNT composites were fabricated by electrochemical polymerization of aniline containing well‐dissolved functionalized MWNTs. The obtained composites can be used as catalyst supports for electrooxidation of formic acid. Cyclic voltammogram results show that platinum particles deposited in PANI/MWNT composite films exhibit higher electrocatalytic activity and better long‐term stability towards formic acid oxidation than that deposited in pure PANI films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010