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。     

普鲁士蓝镶嵌聚吡咯薄膜电极的制备及其电化学电容性质的研究

为提高聚吡咯电极材料电化学性能，研制出一种普鲁士蓝(PB)镶嵌聚吡咯(PPy)薄膜电化学电容器电极。采用化学沉淀法结合气相聚合(VPP)法将同步合成的PB引入PPy薄膜中，制备了自支撑聚吡咯/普鲁士蓝(PPy/PB)复合电极材料。利用扫描电子显微镜、拉曼光谱、X射线粉末衍射技术等对复合材料的形貌及结构进行表征。在三电极体系和对称超级电容器中研究PPy/PB复合材料的电化学表现，研究结果表明，PPy/PB复合材料组装的超级电容器比电容高达447.6 F/g。不同电流密度下充放电性能研究表明，电流密度从1.0 A/g增大到10.0 A/g时，PPy/PB比容量保持率为70.8%,具有优异的倍率性能。通过4 000次恒流充放电后PPy/PB电容保持率为76.9%,高于纯PPy电极材料，显示出较好的电容性能。     

热处理对聚乙烯醇薄膜性能的影响

对聚乙烯醇薄膜进行了热处理,并测试了热处理后薄膜的力学、光学及电学性能,结果表明:增加热处理时间与升高热处理温度对改变聚乙烯醇薄膜的力学性能、光学性能和表面电阻率等效;随着热处理时间的增加或热处理温度的升高,其力学性能增强,光学性能略有下降,表面电阻率增大。     

聚吡咯–聚N-甲基吡咯复合涂料的制备及防腐性能

以三氯化铁为氧化剂,对甲苯磺酸为掺杂剂,采用化学氧化聚合法制得均聚物聚吡咯(PPy)、聚N-甲基吡咯(PNMPy)和共聚物聚吡咯–聚N-甲基吡咯(PPy–PNMPy)。通过扫描电镜、X射线衍射仪、紫外可见分光光度计、傅里叶变换红外光谱仪表征了3种聚合物的微观结构。采用电化学方法和腐蚀溶液浸泡法对比研究了裸钢片、PU(聚氨酯)涂层以及PU–PPy、PU–PNMPy和PU–PPy–PNMPy复合涂层的防腐性能。结果表明,共聚物PPy–PNMPy的致密性优于均聚物PPy和PNMPy。PU–PPy–PNMPy复合涂层的防腐性能和力学性能最优。     

聚吡咯/硫化镉的制备及其光学性能研究

将聚吡咯和纳米粒子结合起来制备的复合材料兼具了导电高分子材料、无机半导体材料的优势,与此同时这种的复合材料还具有显著的三阶非线性光学性质。本文拟采用界面氧化聚合法制备聚吡咯膜,通过实验发现反应的最佳溶剂为三氯甲烷,最佳的氧化剂为过硫酸铵。当聚吡咯于过硫酸铵反应浓度均为0.15 mol/L左右时可以生成表面平整、厚度适中、力学性能较好的聚吡咯膜。通过将上述方法制备的聚吡咯膜先浸泡在醋酸镉溶液中吸附Cd2+,最后与硫代乙酰胺处理得到PPy/CdS复合材料。本实验采用了探针式表面轮廓仪分析、扫描电镜(SEM)、傅立叶红外光谱(FTIR)、X-射线衍射(XRD)、Z-扫描测试法、热重(TG)分析等对产物进行表征。结果表明,聚吡咯/硫化镉纳米复合材料上纳米粒子的分布状况及粒子大小与掺比浓度有关,浓度越低分布越密、粒子直径越小,当聚吡咯、硫化镉的掺杂比达到1:0.001时粒子直径可达20 nm左右。此外,复合了硫化镉纳米粒子后聚吡咯的热稳定性提高了33.3%。由Z-扫描结果显示PPy/CdS具有很强的三阶非线性特性。     

导电复合水凝胶的制备及性能测试

本文首先通过化学交联法制备聚乙二醇二丙烯酸酯-聚丙烯酰胺（PEGDA-PAAm）水凝胶修饰层，而后运用界面聚合法使导电聚合物聚吡咯（PPy）于水凝胶中聚合，则得到性能良好的导电水凝胶。选用316L不锈钢片为负载导电水凝胶的基底，制备掺杂药物地塞米松的水凝胶，通过电化学CV法刺激控制药物释放，实验结果表明，我们到了性能良好的药物释放体系。     

功能化聚吡咯纳米复合材料的应用研究进展

导电聚合物的功能化掺杂改性可提高其多方面性能,扩大应用范围。本文主要介绍了聚吡咯(PPy)具备的开关、电学、力学、光学等多种物理化学性质,并综述了聚吡咯纳米复合材料在柔性电子器件、传感器、超级电容器、光电器件、生物医学等领域的应用研究进展,还提出明确物质的微观形态结构与宏观性质二者之间更直接、更本质的联系对研发新材料、开发新功能、设计新产品具有重要意义。     

化学气相沉积PPy/UHMWPE纤维的研究

采用化学气相沉积制备了聚吡咯/超高相对分子质量聚乙烯(PPy/UHMWPE)纤维,测试了不同氧化剂浓度、不同沉积时间和温度下PPy/UHMWPE纤维的表面剪切强度,用扫描电镜、动态热机械分析仪、傅立叶变换红外光谱仪分析了PPy/UHMWPE纤维的表面形态、热机械性能和复合材料官能团的变化。结果表明:PPy均匀分布在UHMWPE纤维表面,UHMWPE纤维与PPy之间无化学键作用而是分子间作用力;随着氧化剂三氯化铁浓度的增加和吡咯沉积时间的延长,PPy/UHMWPE纤维表面剪切强度先增大后减小;随着处理温度的升高,PPy/UHMWPE纤维表面剪切强度先增大,当处理温度超过85℃时,其剪切强度则减小。     

基于聚吡咯的复合材料气敏元件制作及其对甲醛响应性测试

本文以化学氧化法制备导电聚吡咯(PPy)后,再与功能性碳纳米管(F-CNTs)掺杂于聚氨酯中,制备系列PPy/F-CNTs复合材料,应用在自制电极片上制作成气敏元件。分别采用傅里叶变换红外光谱分析(FT-IR)、X-射线衍射(XRD),扫描电镜(SEM)对复合材料的进行表征,判断其该条件下聚吡咯的导电性能,择优系列气敏元件应用于甲醛气体的响应性测试。结果表明:0.06g F-CNTs/PPy 0.35g复合制备气敏元件,对不同浓度的甲醛溶液在其饱和蒸气压下的测得电阻,得出体积比(V_(甲醛浓):V_水)为1∶2的甲醛溶液气敏元件体现更好的响应性,响应度可达到87.5%。     

聚吡咯／树脂分子复合型导电材料的研制

本文介绍聚吡咯/树脂分子复合型导电材料的研制。在搅拌下将吡咯溶液滴加到调至一定温度的含有FeCh的聚苯乙烯—丙烯腈溶液中,反应3h后制得分子复合型导电材料。探讨了FeCl_3用量、反应温度、吡咯用量等因素对导电性能的影响。结果表明,FeCl_3/吡咯在1∶2～3范围内,反应温度在40℃以上,材料具有较高的电导率;电导率随吡咯用量的增加而提高,当吡咯量达到树脂量的30%以上时,电导率趋于平稳。本文所得聚吡咯为可溶性聚合物。所得复合材料可加工成薄膜等形式,电导率在10_(-3)～10_(-4)·cm~(-1)范围。     

Preparation of a porous conducting polymer film by electrochemical synthesis–solvent extraction method

Porous conducting polypyrrole (PPy) films have been obtained by electrochemical synthesis–solvent extraction method. The results of scanning electron microscopy (SEM) show that the size and the distribution of pores can be controlled during the electrochemical synthesis. The porous PPy films have sufficiently good mechanical properties, and electrochemical voltammetric studies imply that the porous films also have high electrical conductivity and good electrochemical reversibility. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 303–307, 2004     

Structural,mechanical, and electrical properties of electropolymerized polypyrrole composite films

Electrochemical polymerization of pyrrole in a solution containing dissolved poly(vinyl alcohol) (PVA) produces a homogeneous, free‐standing, flexible, and conductive polymer film. The films were characterized using infrared spectroscopy, wide‐angle X‐ray diffraction analysis, and scanning electron microscopy. The appearance of standard and some new absorption bands for polypyrrole (PPy) and PVA confirms the composite formation. The mechanical properties of conducting PVA + PPy films were studied and found to be improved with respect to the control PPy films. The electrical conductivity of the PVA + PPy films was measured by using standard four‐ and two‐probe methods. The conductivity of the films was found to depend on the pyrrole content. These conducting composites were further used as gas sensors by observing the change in current with respect to ammonia gas. It was observed that the current decreases when these composites were exposed to ammonia gas. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2511–2517, 2001     

A study of microwave transmission,reflection, absorption,and shielding effectiveness of conducting polypyrrole films

Microwave transmission, reflection, and absorption behavior and the shielding effectiveness of electrochemically synthesized polypyrrole films with dc conductivities ranging from 0.001 to 50 S/cm are presented. Results show that the electrical conductivity of the doped polypyrrole films has a significant effect on transmission, reflection, and absorption of microwaves. Heavily doped, conducting films were highly reflective, whereas lightly doped, semiconducting films had very high transmission. Intermediate conductivity polypyrrole samples were highly absorptive. The agreement between experimental data and theoretical modeling provided confidence to extend the modeling to include the effect of sample thickness on the transmission, reflection, and absorption properties of films with a wide range of conductivity values, hence, providing valuable information for the design of microwave devices and fundamental understanding of the material properties. A method of measuring the far-field sheilding effectiveness of polypyrrole films is also presented. Results of shielding experiments indicated the potential for such applications. © 1994 John Wiley & Sons, Inc.     

Polypyrrole–poly(heptamethylene p,p′-bibenzoate) conducting materials. Synthesis and characterization

Polypyrrole–poly(heptamethylene p,p′-bibenzoate) conducting materials, PPy–P7MB/ClO₄, were obtained by anodic coupling of pyrrole into a polybibenzoate inert matrix, using perchlorate anions as dopant agent. P7MB is a main-chain liquid crystalline polybibenzoate with adequate mechanical properties and elastic modulus of 1.4GPa at room temperature. The method of synthesis, galvanostatic or potentiostatic electrodeposition, is responsible for differences in the PPy–P7MB/ClO₄ films electrochemical response. FTIR spectra show the complex structures of P7MB and the composite conducting material. The conductivity of PPy–P7MB/ClO₄ films maintains a relatively high value, σ = 13.74Scm^?1, in spite of the insulating effect of polybibenzoate. Film micrographs reveal the typical cauliflower morphology exhibited by polypyrrole and the evolution of film growth with time.     

Polypyrrole/carbon nanotube composites: Molecular modeling and experimental investigation as anti-corrosive coating

In this work we present a computational method based on molecular mechanics (MM) and dynamics (MD), to predict mechanical properties of polypyrrole (PPy)/polyaminobenzene sulfonic acid-functionalized single-walled carbon nanotubes (CNT-PABS) and PPy/carboxylic acid-functionalized single-walled carbon nanotubes (CNT-CA) composites. Furthermore, experiments were carried out to assess the anticorrosive features of the PPy film and CNT-PABS and CNT-CA PPy reinforced composite coatings. Computational bulk models of PPy/CNT-PABS and PPy/CNT-CA were implemented at atomistic scale and composite coatings were grown in situ onto carbon steel (OL 48-50) electrodes. PPy, PPy/CNT-PABS and PPy/CNT-CA computational models and films were investigated concerning mechanical properties by using computational tools. The obtained films were assessed experimentally as anticorrosive materials using potentiodynamic measurements, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results clearly confirmed that the CNT-PABS and CNT-CA are properly dispersed in the composite coatings and have beneficial effect on mechanical integrity. Moreover, the anticorrosion protecting ability of the composite coatings is significantly higher than the one characteristic to pure PPy. The Young's moduli generally increased with increasing of CNT content and values ranged from 2.67 GPa in the case of pure PPy to 4.15–4.61 GPa in the case of PPy/CNT-PABS composite system.In agreement with earlier results from the literature for conducting polymer organic coatings, the higher conductivity of material leads to a more efficient anticorrosion protection capability, our results exhibited an enhance of conducting features even for very low mass of CNT-PABS or CNT-CA loaded in composites coatings therefore, an improvement of anticorrosion protecting ability.     

Reaction rate and electrochemical stability of conducting polymer films used for the reduction of hexavalent chromium

The reduction of toxic hexavalent chromium to its trivalent state at conducting polymers films was studied. The process is based on the capacity of conducting polymers to spontaneously donate electrons to the Cr(VI) species. Electrodes of polyaniline and polypyrrole, deposited as films on reticulated vitreous carbon (RVC), were prepared. The process of Cr(VI) reduction was studied under open and closed circuit conditions. It was observed that polyaniline was only suitable for use only under closed circuit conditions, whereas polypyrrole did not perform well under either open or closed circuit conditions. The electrocatalytic power of polyaniline for Cr(VI) reduction was demonstrated when the reaction rates for bare RVC and RVC/PANI were compared.     

Evidence of redox interactions between polypyrrole and Fe3O4 in polypyrrole-Fe3O4 composite films

The electrical properties of conducting polymers make them useful materials in a wide number of technological applications. In the last decade, an important effect on the properties of the conducting polymer when iron oxides particles are incorporated into the conductive matrix was shown. In the present study, films of polypyrrole were synthesized in the presence of magnetite particles. The effect of the magnetite particles on the structure of the polymer matrix was determined using Raman spectroscopy. Mass variations at different concentrations of Fe₃O₄ incorporated into the conducting matrix were also measured by means of quartz crystal microbalance. Additionally, the changes in the resistance of the films were evaluated over time by electrochemical impedance spectroscopy in solid state. These results show that the magnetite incorporation decreases polymeric film resistance and Raman experiments have evidenced that the incorporation of magnetite into polymeric matrix not only stabilizes the polaronic form of the polypyrrole, but also preserves the polymer from further oxidation.     

Resistance of the Polypyrrole/Polyimide Composite by Electrochemical Impedance Spectroscopy

Electrically conducting polymers are promising for applications in polymer based charge storage devices and for membrane applications. Composing polypyrrole with polyimide improves mechanical properties of polypyrrole and affects the electrochemical properties of the composite. In this paper resistance to ion flow of pure polyimide and of the polypyrrole/polyimide composite were studied by electrochemical impedance spectroscopy, comparatively, as a function of applied potentials and of amount of polypyrrole. Electron scanning microscopy and surface mapping were used for surface characterization. Observed behavior was explained with electroactivity of the components of the composite. Conclusions about the effect of polypyrrole on the structure and resistance were made.     

Formation of transparent conducting films based on core‐shell latices: Influence of the polypyrrole shell thickness

Transparent conducting latex films have been prepared from core‐shell latices. The latex particles have a poly(butyl methacrylate) (PBMA) core of about 700 nm and a very thin polypyrrole (PPy) shell. We have studied the film formation of latices with 1, 2, and 4 wt % PPy and compared this with the film formation of the pure PBMA latex. The film formation process was studied by transparency measurements, atomic force microscopy surface flattening, and transmission electron microscopy on ultrathin sections of films after various annealing times at 120°C. It is demonstrated that highly transparent (>90%) and antistatic films can be produced using these latices. The presence of a polypyrrole shell around the PBMA latex particle seriously hinders the deformation of the particles. The amount of polypyrrole, and thus the shell thickness, is the determining factor for the speed of film formation. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 900–909, 2001