聚吡咯/蒙脱土复合材料的制备与性能

以水为介质，FeCl3为氧化剂，用化学氧化法制备了聚吡咯／蒙脱土复合材料。研究了反应温度、反应时间、蒙脱土和氧化剂用量、掺杂剂种类及用量等因素对聚合反应的影响，确定了最佳反应条件。同时考察了材料的导电稳定性。结果表明，温度是此反应最主要的影响因素，O℃时制备的复合材料的电导率已迭50．0S／cm。其导电稳定性也优于其它同类材料。50d内，低温产物电导率下降不到10％。     

聚吡咯及其复合材料导电稳定性研究

本文研究了聚吡咯(PPY)及其复合材料在不同条件下的导电稳定性。发现聚吡咯导电性的下降是由化学降解所致,这一降解反应符合一级反应动力学。时效研究表明,复合材料导电稳定性与基体及填充相的热膨胀、基体材料的热机械稳定性有关。复合材料内部渗流途径断裂引起导电性的下降。     

聚吡咯导电涂层的制备及其性能研究

以十二烷基苯磺酸(BADS)为掺杂剂,过硫酸铵(APS)为氧化剂,化学法合成聚吡咯(PPy);并与羟基丙烯酸树脂配制成PPy导电涂层。用四探针测试仪测定不同反应条件下的PPy电导率,分析不同因素对PPy导电性的影响;运用扫描电镜(SEM)、激光粒度仪、电阻测试仪、紫外老化机、热分析仪、电化学工作站等对涂层进行表征。结果表明:PPy颗粒平均粒径约为1μm,且在涂层中分布均匀;20%PPy导电涂层的导电性最好,达到2.5×10^-4 S/cm;涂层经紫外加速老化720 h,导电性和附着力有所下降;涂层热稳定性较好,最终失重温度为500℃左右;PPy导电涂层的防腐蚀性优于纯树脂,5%PPy导电涂层的防腐蚀性最佳。     

聚吡咯及其复合材料的合成与导电性能研究

以水为反应介质,用硅烷偶联剂(MPS)对纳米级粒子二氧化硅(SiO2)进行预处理,用化学氧化聚合方法合成了聚吡咯/二氧化硅(PPy/MPS-SiO2)复合材料.对影响聚合反应的诸因素(温度、时间、搅拌速度等)进行了探讨,利用红外光谱、元素分析、电镜、四探针技术表征了这些材料的组成、结构和性能.     

聚吡咯导电薄膜原位聚合工艺的研究

以吡咯单体的水溶液为原料,氯化铁为引发剂,利用原位聚合法在玻璃纤维板表面生成一层聚吡咯(PPy)薄膜。探讨了吡咯单体浓度、聚合温度、聚合时间、聚合pH值、引发剂用量5个工艺条件对PPy膜电导率的影响。结果表明制得高电导率的工艺条件为:吡咯单体浓度0.041mol·L-1,温度20℃,FeCl3·6H2O 3.13g,pH值为2.6,聚合20min;电导率最好可达9.259S·m-1。在该工艺下得到的PPy膜的电导率随时间变化的规律,发现电导率基本不变,稳定性很好。     

聚吡咯导电复合材料结构和特性研究

介绍了低密度聚乙烯（聚苯乙烯）／聚吡咯复合材料的导电特性。发现复合材料的导电率和聚吡咯含量的关系可用“渗流理论”来描述，复合材料制备工艺强烈地影响其微观结构从而影响渗流门槛值。讨论了复合材料导电率的温度依赖性行为和结构的关系。     

织物增强聚吡咯导电复合材料的制备及特性

利用气相反应可以快速简单地制备织物增强聚吡咯复合材料，在２．３ｗｔ％聚吡咯含一下复合材料具有优良的导电性。由于气相反应合成的聚吡咯是附在纤维表面的薄层，因此在室温条件下材料具有较好的导电稳定性。     

聚吡咯／木单板导电复合材料的制备与表征

以FeCl3为氧化剂和掺杂剂，采用化学氧化原位吸附聚合法制备了聚吡咯／木单板复合材料。探讨了制备条件对表面电阻率和吸聚率的影响，以及获得的较优的制备条件。利用红外光谱（FT-IR）、X射线衍射（XRD）和扫描电镜（SEM）表征了材料的组成、结构和形貌。结果表明，制备条件为：单板室温吸附吡咯单体的时间30min，FeCl3浓度0．75mol／L，聚合反应时间30min，反应温度25℃。复合材料的表面电阻率可这15．53Ω／cm^2。复合材料中木单板表面吸附聚合了无定形的掺杂态的聚吡咯，聚吡咯排列紧密，有少量孔隙，无明显的方向性，且与木材表面有一定的相互作用。     

聚吡咯/蒙脱土纳米复合材料的表征与复合机理

以水为介质，用化学氧化就地吸附聚合法(in：situpolymerization)制备了聚吡咯(PPy)／蒙脱土(MMT)纳米复合导电材料。利用红外光措(FT-IR)、热失重(TGA)、X射线衍射(XRD)和四探针技术表征了材料的组成、结构和性能。结果表明PPy键已进入MMT内层空间，二者达到了纳米级复合。纳米复合材料的电导率已达50S／cm。     

聚吡咯导电材料合成方法的进展

本文对聚吡咯及聚吡咯导电复合物的合成方法进行了综述。     

The stability of polypyrrole and its composites

The stability of chemically and electrochemically polymerized polypyrrole and its composites has been investigated. The results demonstrate that the oxidative degradation of polypyrrole and the interruption of the percolation path of the composites can cause a strong decrease in electrical conductivity. The possible mechanisms of oxidative degradation of polypyrrole and the interruption of the percolation path of the composites are also discussed. This revised version was published online in November 2006 with corrections to the Cover Date.     

Radiolytic synthesis of conducting polypyrrole/carbon nanotube composites

Conducting polypyrrole (PPy)/multi-wall carbon nanotube (MWNT) composites have been synthesized by the in situ gamma radiation-induced chemical polymerization method at room temperature. The resulting cable-like morphology of the composite (PPy–MWNT) structures was characterized by elemental analysis, Fourier transform infrared, field-emission scanning electron microscope, thermal gravimetric analysis, X-ray photoelectron spectroscopy, and transmission electron microscope. The standard four-point probe method was utilized for measuring the conductivity of the samples. We observed no significant chemical reaction between the polymer and carbon nanotube, which only showed that polypyrrole chains are tightly coated on to MWNT. The physical properties of the composites (PPy–MWNT) were measured and showed that the MWNT were modified by conducting polypyrrole with various properties enhanced.     

Preparation and characterization of conducting polycaprolactone/chitosan/polypyrrole composites

A novel processing method was developed to produce conducting polycaprolactone/chitosan/polypyrrole composite membranes. Results obtained from infrared and X-ray spectra as well as thermal dynamic measurements demonstrated that there were pronounced interactions between polycaprolactone and chitosan components, and composite membranes had partially miscible microstructures. It was found that some composite membranes showed conductivity transitions at a polypyrrole load of around 2 wt.%, and significantly enhanced conductivity for these composite membranes was already achieved in overall interval of polypyrrole loads compared to those membranes composed of a single component and polypyrrole particles. The tensile properties of composite membranes both in dry and wet state were examined, and the results revealed that the tensile mechanical properties of hydrated composite membranes could be well maintained if weight ratios of polycaprolactone to chitosan were selected as appropriate values.     

Thin conducting polypyrrole film on insulating surface and its applications

An electrically conductive plastic material was obtained by the polymerization of pyrrole on insulating polymeric materials and nylon cloth impregnated with the oxidant by vapour phase technique, resulting in a uniform, smooth and adherent coating of conducting polymer having a surface resistance ranging from 200 Ω/□ to 20 kΩ/□, which makes it suitable for applications as an antistatic material.     

On the electrical anisotropy of conducting polypyrrole

The electrical properties of polypyrrole films prepared by electrochemical polymerization have been studied. The films were electrochemically and optically characterized. A very high anisotropy of the resistivities and mobilities, both parallel and perpendicular to the substrate, has been found. The results obtained are consistent with a hopping model for the conduction mechanism, with the interchain hopping much lower than the intrachain hopping, if it is assumed that the chains are oriented preferentially parallel to the substrate.     

Microstructure-mechanical properties relationship in conducting polypyrrole films

In this paper, the microstructures of electrochemically synthesized conducting polypyrrole (PPy) films were studied by scanning electron microscopy (SEM). It was found that the polymer film growth condition has strong effects on mechanical properties of the polymer film. The relationship between mechanical properties (such as tensile strength and brittle—tough properties) and the microstructures of PPy films was described for the first time. The effect of electrochemical polymerization condition including temperature and electrolyte composition on the strength and brittle—tough properties was also studied. Films deposited both on the surface of the anode facing the counter electrode and on the back surface were characterized. In order to improve the mechanical properties of PPy films, an optimal condition of electrochemical synthesis of conducting PPy films has been recommended.     

Synthesis of ferrofluid based nanoarchitectured polypyrrole composites and its application for electromagnetic shielding

The monodispersion of magnetic nanoparticles in conducting polymer is the prerequisite to make a high quality composite for tunable electromagnetic interference (EMI) shielding. To meet this challenge, we have designed and synthesized ferrofluid based nanoarchitectured polypyrrole composites containing Fe₃O₄ (8–12 nm) via in situ oxidative polymerization. To tune the microwave signals, polypyrrole composites (PFF) with different monomer/ferrofluid weight ratios have been prepared and characterized in microwave frequency domain. A maximum shielding effectiveness value of SE_A(max) = 20.4 dB (∼99% attenuation) due to the absorption of microwave has been observed in the frequency range of 12.4–18 GHz and attenuation level varied with ferrofluid loading. The electrical conductivity of PFF composite is of the order of 10⁻² S cm⁻¹ order and having superparamagnetic nature with saturation magnetization (M_s) of 5.5 emu g⁻¹. The lightweight PFF composites with high attenuations can provide full control over the atomic structure and are favorable for the practical EMI shielding application for commercial electronic appliances.