PA6/聚苯胺复合材料的研制

通过共混、原位聚合方法制备尼龙(PA)6/聚苯胺(PANI)复合材料,并利用不同的改性剂改性PA6/PANI复合材料.结果表明,改性复合材料中PANI的微观结构为纳米结构.当采用复合改性剂十六烷基三甲基溴化胺(CTAB)、1,5-萘二磺酸(1,5-NDA)改性PA6/PANI复合材料时,PANI的分散性最好,且具有较均一的纳米球结构.与未改性PA6/PANI复合材料相比,CTAB-1,5-NDA改性复合材料的电导率有显著提高,当PANI质量分数分别为20%、40%时,复合材料的室温电导率分别可达4.64×10-2S/cm和0.13 S/cm,该复合材料在电极材料方面具有广阔的开发和应用前景.     

PLA/PPy复合材料的制备及表征

以吡咯(Py)为原料,通过原位聚合法合成聚吡咯(PPy)导电粒子,通过PPy粒子对聚乳酸(PLA)进行改性,制备PLA基导电复合材料,并对其形貌、力学性能及导电性能进行测试。结果表明:PPy可以与PLA基体呈现一种紧密结合的状态;PLA/PPy(5%)导电复合材料综合性能最佳,其拉伸强度为51.2 MPa、断裂伸长率为163.5%、电导率为4.12×10~(-5) S/cm。     

超声辅助原位聚合聚吡咯/石墨烯纳米复合材料的制备及其性能研究

利用超声波的分散、粉碎、活化、引发等多重作用以及吡咯单体与石墨烯的π-π相互作用,在实现石墨烯均匀分散的同时,使吡咯单体在石墨烯表面进行原位聚合反应,制备出聚吡咯/石墨烯(PPy/RGO)纳米复合材料。运用扫描电子显微镜(SEM)、红外光谱(FTIR)、X射线光电子能谱(XPS)等测试手段对PPy/RGO纳米复合材料的表面特性、化学组成及结构等进行了表征。在此基础上,研究了制备过程中的各种因素(如氧化剂、反应温度、石墨烯含量等)对PPy/RGO纳米复合材料产率及导电性能的影响。并采用热重分析(TGA)和导电测试分析了石墨烯含量对其热稳定性及电导率的影响。     

CNTs表面包覆PPy对PVC复合材料电导率的影响

为促进碳纳米管(CNTs)更为有效地应用于聚合物抗静电复合材料,采用原位聚合在CNTs表面生成聚吡咯(PPy)包覆层得到CNT-PPy,其组成通过傅立叶变换红外光谱分析和热重分析确认。CNT-PPy作为导电剂添加到聚氯乙烯(PVC)中制备PVC/CNT-PPy复合材料,对比分析PVC/CNT-PPy复合材料电导率的变化规律可得:PPy修饰CNTs可降低PVC/CNT-PPy复合材料中CNTs的逾渗阈值;当PPy包覆层在CNT-PPy中质量分数约为51.1%,CNT-PPy在复合材料中的质量分数为3%时,制得PVC复合材料的电导率可达到10–7 S/cm量级。由此可知,CNTs表面可控的PPy修饰量对PVC/CNTs复合材料抗静电性能起到显著的提升作用,为CNTs作为高性能导电剂应用提供更多的空间。     

绢云母在丁苯橡胶中的应用

以滁州绢云母为填料,将其改性后制备了改性绢云母/丁苯橡胶(SBR)复合材料,考察了复合材料物理机械性能的影响因素,并通过傅里叶变换红外谱(FTIR)表征了改性绢云母和复合材料。结果表明,在改性剂WD 81质量分数为2.0%、改性温度为90℃、改性时间为25 min以及改性绢云母用量为80份、硫化温度为150℃、硫化时间为12 min的条件下制得的改性绢云母/SBR复合材料的拉伸强度、扯断伸长率、撕裂强度和邵尔A硬度分别达到6.81 MPa、856%、28.04 k N/m和56;改性绢云母/SBR复合材料的官能团发生了加成聚合反应,改性剂起到"桥梁"作用,提高了绢云母对SBR基体的增强作用。     

基于细菌纤维素的导电功能复合材料的制备及用于导电纸

以具有三维纳米纤维网络结构的细菌纤维素（BNC）为支撑基底,碳纳米管（CNT）或聚吡咯（PPy）为填充导电材料,通过原位生物培养复合制备导电功能复合材料,并将其应用于导电纸。采用了静态浅瓶培养、动态水平转鼓培养,以及氧化聚合法制备了多种BNC基导电功能复合材料,并对各导电复合膜的产量、宏观及微观（SEM）形貌、力学性能、结晶度、比表面积、导电性能等进行表征,探究最优的制备方式及反应条件,制备出性能优异的BNC基导电纸。结果表明,水平动态转鼓的发酵方式使得CNT的分布更均匀,动态制备的D-BNC/CNT复合膜的电导率随着CNT的负载量增加而增加,质量浓度为1%(wt)的D-BNC/CNT复合膜的电导率（0.94 S/cm）约为静态制备的S-BNC/CNT(0.015 S/cm)的62倍。氧化聚合法制备的D-BNC/PPy导电复合膜,在浓度为0.4%(wt)时力学性能（杨氏模量为3.65 MPa）与导电性能（电导率为0.14 S/cm）最优。D-BNC/1%(wt)CNT/0.4%(wt)PPy导电纸与市售的导电纸相比,导电性能具有明显的优势（二极管的光亮强度更大）,导电率达到2.87 S...     

聚吡咯/羧酸化细菌纤维素复合材料的电学性能研究

基于细菌纤维素的多羟基结构，对其进行羧酸化改性；接着以羧酸化细菌纤维素为模板，原位复合聚吡咯（PPy），得到PPy/羧酸化细菌纤维素导电复合材料。并对其微观形貌、化学结构、热稳定性等进行测试表征，重点研究了用不同浓度的氧化剂处理后，复合材料电学性能的变化。结果表明，电子电导率随氧化程度的提高而升高，最高可达10^-3 S/cm，编号为0.04-48h的样品具有最佳的离子电导率。     

纳米云母改性聚丙烯复合材料的制备及性能研究

以聚丙烯(PP)为基体及纳米云母为改性剂,用混炼法制备纳米云母/聚丙烯复合材料。对未改性的纳米云母、烷基改性的纳米云母及甲基丙烯改性的纳米云母与聚丙烯的复合材料的力学性能和热性能进行比较分析。结果表明,经傅里叶变换红外光谱(FTIR)分析,证实纳米云母已成功改性,由扫描电子显微镜(SEM)分析,云母粉末为纳米级,改性影响了聚丙烯和云母之间的结合性,与未改性的云母相比,改性云母的各项性能较好。通过X射线衍射(XRD)分析,纳米云母不会影响聚丙烯的结晶行为和收缩关系。在力学性能方面,纳米云母(1 phr)虽然可以增加拉伸强度,但随着纳米云母的添加增加至7phr,复合材料变硬变脆而下降,拉伸强度略微下降,冲击强度显著下降,而拉伸模量和表面硬度都提高10%以上,表明改性后的纳米云母与聚丙烯融合性更强。在热性能方面,在7 phr纳米云母添加量下,其维卡软化温度提高约10%,表明添加烷基改性比甲基丙烯改性云母的复合材料稳定性更好;随着云母添加量增加,耐热性提升效果明显,但因改性剂会先裂解,导致改性的纳米云母降低了纳米复合材料的耐热性。     

聚吡咯包覆纤维状海泡石改性硅橡胶复合材料的制备及性能

以改性纤维状海泡石(oSep)为载体,采用原位聚合法制备聚吡咯(PPy)包覆的纤维状海泡石(PPy@oSep)导电纤维,再以室温硫化硅橡胶(RTV-SR)为基体制备硅橡胶(PPy@oSep/RTV-SR)复合材料.利用傅里叶变换红外光谱和扫描电子显微镜表征PPy@oSep的分子结构和微观形貌,并用万能电子拉伸试验机和绝...     

秸秆纤维的改性对PBS复合材料性能的影响

采用改性剂改性后的玉米秸秆纤维增强聚丁二酸丁二醇酯(PBS),利用热压工艺得到了秸秆纤维/PBS复合材料;研究了苯甲酸、硬脂酸、硅烷、壳聚糖及乙酸5种改性剂对经超声波处理后的秸秆纤维/PBS复合材料性能的影响;采用EDS、SEM、FTIR及WXRD对改性前后的纤维及复合材料进行了分析.研究结果表明:5种改性剂对纤维均有改性效果,苯甲酸质量分数为2%-3%时,复合材料力学性能最优.     

Preparation and characterization of graphite oxide/polypyrrole composites

Graphite oxide (GO)/polypyrrole (PPy) composites (GPs) and 1,5-naphthalene disulfonic acid (1,5-NDA) doped GPs (1,5-NGPs) have been successfully synthesized via in situ polymerization of pyrrole on GO. The conductivity of 1,5-NGPs is as high as 7 S/cm, seven orders of magnitude higher than that of pristine GO. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results show PPy “dressed” on the surface of GO layers, while Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses confirm the interaction between GO and PPy. The results of thermogravimetric analysis (TGA) and heat treatment at 1000 °C show that the “dressed” PPy on the surface of GO layers in GPs and 1,5-NGPs has effectively prevented the deflagration of GO.     

碳纳米管材料导热性能的实验研究

本文对碳纳米管与环氧树脂(Epoxy-EP)复合材料的导热性能进行了定量的研究,探索了CNTs/EP复合材料的制备方法,运用Hotdisk热常数分析仪研究了CNTs/EP复合材料的导热系数;利用CNTs/EP两相复合材料的导热理论模型得到了室温下单壁碳纳米管(Single-Wall Carbon Nanotubes-SWCNTs)的导热系数为3980 W/(m.K),双壁碳纳米管的导热系数(Double-Wall Carbon Nanotubes-DWCNTs)为3580 W/(m.K),以及多壁碳纳米管(Multi-Wall Carbon Nanotubes-MWCNTs)的导热系数为2860 W/(m.K)。     

Effect of Mixing Process and Morphologies on the Electrical Conductivity of PA6/EVA/CB Composites

Nylon6 (PA6)/Ethylene-(vinyl acetate) (EVA)/carbon black (CB) composites with different electrical conductivity were prepared in an internal mixer. The factors influencing the electrical conductivity of the ternary composites were investigated, including mixing mode, mixing time and mass ratio of PA6 and EVA, and so on. Among three kinds of PA6/EVA/CB composites, including ones prepared by directly mixing (composites A), EVA and CB were mixed prior to melt-compounding with PA6 (composites B) and PA6 and CB were mixed prior to melt-compounding with EVA (composites C), the mixing time only significantly influenced the electrical conductivity of composites A. Good conductivity of the composites could be realized because the distance between CB particles became closer with the increasing of mixing time. However, the mixing time has no effect on the electrical properties of the composites B and the composites C, due to there were no CB particles migrated phenomenon happened. Scanning electron microscopy (SEM) was used to assess the fracture surface morphologies and the dispersion of the CB particles. The results showed that the dispersion of the CB particles significantly affects the electrical conductivity of the composites. Based on the study of the influence of various mass ratios of EVA and PA6 on the morphologies and electrical properties of PA6/EVA composites filled with 10 phr (parts per hundred resins) CB particles, we suggested that the mass ratio of EVA and PA6 affected the volume resistivity of the ternary composites significantly. In addition, the composites were almost insulation when the mass ratios of EVA and PA6 were 80/20 and 70/30, while the composites became conductivity with the mass ratio of EVA and PA6 higher than 60/40. The PA6/EVA/CB composites which CB particles locate at the interface of EVA and PA6 have the lowest volume resistivity when the mass ratio of two components was 60/40.     

A novel soluble PANI/TPU composite doped with inorganic and organic compound acid

A series of novel soluble and thermoplastic polyurethane/polyaniline (TPU/PANI) composites doped with a compound acid, which was composed of an organic acid (p‐toluene sulfonic acid) and an inorganic acid (phosphoric acid), were successfully prepared by in situ polymerization. The effect of aniline (ANI) content, ratio of organic acid/inorganic acid, and different preparation methods on the conductivity of the TPU/PANI composites were investigated by using conductivity measurement. Lithium bisoxalato borate (LiBOB) was added to the prepared in situ TPU/PANI to coordinate with the ether oxygen groups originating from the soft molecular chains of TPU, and thus the conductivity of the composites was further enhanced. The molecular structure, thermal properties, and morphology of the TPU/PANI composites were studied by UV–visible spectroscopy, differential scanning calorimetry, and scanning electron microscopy, respectively. The results show that the in situ TPU/PANI composites doped with the compound acid can be easily dissolved in normal solvents such as dimethylformamide (DMF) and 1,4‐dioxane. The conductivity of the TPU/PANI composites increases with the increase of the ANI content, in the ANI content range of 0–20 wt %; however, the conductivity of the composites reduces with further increment of ANI content. The conductivity of the TPU/PANI composites prepared by in situ polymerization is about two orders of magnitude higher than that prepared by solution blending method. LiBOB can endow the in situ TPU/PANI composites with an ionic conductivity. The dependence of the conductivity on temperature is in good accordance with the Arrhenius equation in the temperature range of 20–80°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Mechanical and thermophysical properties of carbon/carbon composites with hafnium carbide

Carbon/carbon (C/C) composites with addition of hafnium carbide (HfC) were prepared by immersing the carbon felt in a hafnium oxychloride aqueous solution, followed by densification and graphitization. Mechanical properties, coefficients of thermal expansion (CTE), and thermal conductivity of the composites were investigated. Results show that mechanical properties of the composites decrease dramatically when the HfC content is greater than 6.5 wt%. CTE of the composites increases with the increase of HfC contents. The composites with addition of 6.5 wt% HfC show the highest thermal conductivity. The high thermal conductivity results from the thermal motion of CO in the gaps and pores, which can improve phonon–defect interaction of the C/C composites. Thermal conductivities of the composites decrease when the HfC content is greater than 6.5 wt%, which is due to formation of a large number of cracks in the composites. Cracks increase the phonon scattering and hence restrain heat transport, which results in the decrease of thermal conductivity of the composites.     

氮化硼纳米片改性复合材料导热性能的研究进展

氮化硼纳米片（BNNSs）是一种二维片状纳米材料，具有较高的导热性和热稳定性。将其作为填料加入聚合物中，可显著提高复合材料的导热性能。本文基于近年来对BNNSs改性复合材料的导热性能的研究进展，总结了BNNSs制备和改性的方法以及建立导热路径的方法，介绍了该体系复合材料的导热机理，分析了影响复合材料导热性能的因素，最后对提高复合材料的导热性能进行了展望。     

Effects of phenolic resin contents on microstructures and properties of c/sic-diamond composites

In this paper, C/SiC-diamond composites were obtained by chemical vapor infiltration (CVI) and reactive melt infiltration (RMI), and the effects of phenolic resin contents on the microstructures and properties of as-obtained C/SiC-diamond composites were studied. The results suggested a significant influence of phenolic resin contents on the pore structure of the composites before reactive melt infiltration (RMI), as well as phase composition and density of the matrix after RMI. The mechanical properties of composites were shown to correlate with the threshold effect of phenolic resin. Sample R5 prepared with high phenolic resin contents displayed significantly declined mechanical properties. On the other hand, adjustment of the phenolic resin content yielded samples with maximum room temperature thermal conductivity reaching 14.75 W/(m·K). The theoretical thermal conductivity of the composites calculated by the Hasselman-Johnson (H-J) theoretical model was estimated to 24.52 W/(m·K). Overall, the increase in phenolic resin content led to unreacted diamond-C regions and the formation of substantial porosity. These features reduced the thermal conductivity of the resulting C/SiC-diamond composites.     

Effect of nanosized carbon black on the morphology,transport, and mechanical properties of rubbery epoxy and silicone composites

Three different types of nanosized carbon black (CB), Printex XE2 (CBP), Vulcan XC72, and Printex 140 U (CBU), were dispersed by mechanical mixing in rubbery epoxy (RE) and silicone to produce composites. It was found that the maximum possible loading of CB in the polymers depended on the surface area of CB. For a given loading, all three CBs produced similar improvements in the thermal conductivity of the resulting composites, but their effects on the electrical conductivity varied and ranged from insulating composites with CBU to conducting composites with CBP. CBP produced a greater improvement in the electrical conductivity than the thermal conductivity of the polymers compared to the other CBs. This was attributed to the high structure of CBP, which led to the formation of a concatenated structure within the matrix. The CB/silicone composites had a similar thermal conductivity to that of the CB/RE composites, but only the CBP/silicone composite produced at 8 wt % loading was electrically conducting. The compression and hardness properties of RE were also significantly improved with the addition of CB. However, in the case of silicone, only CBP had a considerable effect on the compression properties. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of flake graphite on property optimisation in thermal conductive composites based on polyamide 66

In this study, in order to improve the thermal conductivity of polyamide 66(PA66), PA66 composites filled with flake graphite (FG) were prepared by twin-screw extruder. Effects of filler content, particle size and particle size mixing on thermal conductivity, mechanical and rheological properties of the composites were investigated. The results showed that as FG content increased from 0 to 50 wt-%, thermal conductivity of the composites filled with 100 μm FG gradually increased, whereas mechanical properties and rheological properties decreased. At 50 wt-% loading, thermal conductivity reached 3.07 W/(m K). With the increase of particle size, thermal conductivity and rheological properties of the composites improved, but mechanical properties increased first and then decreased. The composite filled with 100 μm FG had relatively optimal mechanical properties. Particle size mixing can improve thermal conductivity and the maximum value was achieved in the 1:2 mass ratio of 20 and 100 μm particles.