磺酸盐型水性聚氨酯/聚吡咯导电材料的原位制备与电阻性能

以聚乙二醇(PEG1000)、异佛尔酮二异氰酸酯(IPDI)以及2,4-二氨基苯磺酸钠(DASS)为原料,通过预聚体法合成了磺酸盐型水性聚氨酯分散液(SWPU)。再以FeCl3为氧化剂,采用原位化学氧化聚合法使吡咯(Py)在SWPU中聚合,制备了磺酸盐型水性聚氨酯/聚吡咯(SWPU/PPy)导电复合材料。研究了制备条件(如投料比和投料顺序)、反应条件等对磺酸盐型水性聚氨酯/聚吡咯(SWPU/PPy)导电复合材料电阻性能的影响。红外光谱图表明PPy与SW-PU分子间存在氢键缔合。实验结果亦表明,最佳制备条件为:Py浓度为30%,n(FeCl3)/n(Py)=2.2,投料顺序为SWPU→Py→FeCl3,反应温度0℃(冰浴),反应时间为3h,SWPU/PPy电阻率可达到1Ω·cm。     

导电聚吡咯/醋酸纤维素复合膜的合成及性能研究

采用相分离原位聚合法在醋酸纤维素(CA)基体中合成聚吡咯(PPy),可制成均匀的PPy/CA导电复合薄膜,成膜后朝向玻璃的膜面(反面)是绝缘的,而朝向溶液的膜面(正面)却是导电的.膜中吡咯/醋酸纤维素的投料比为0.091时,导电复合膜的表面电阻约为20Ω/cm.通过红外光谱(FTIR)、原子力显微镜(AFM)对导电复合膜两面的化学组成、表面形态进行了表征.分析了制备条件对PPy/CA复合膜导电性能的影响.     

UV固化聚吡咯/聚氨酯导电涂膜的制备与性能研究

以聚四氢呋喃醚二醇(PTMG1000)、异佛尔酮二异氰酸酯(IPDI)、1,4-丁二醇(BDO)以及甲基丙烯酸羟乙酯(HEMA)等为原料合成得到热塑性聚氨酯,以吡咯(Py)、十二烷基苯磺酸(DBSA)、过硫酸铵(APS)制备了PPy-DBSA复合物.将聚氨酯与PPy-DBSA在四氢呋喃(THF)中反应,并加入活性稀释剂、光引发剂等制备得到PPy-DBSA/TPU导电复合涂层材料.研究了PPy-DBSA粒子含量等因素对导电膜力学性能和导电性能的影响,实验结果表明,PPy-DB-SA占体系总质量的20％时,膜的整体性能达到相对最佳水平.     

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。     

导电聚合物及导电聚吡咯的研究进展

综述了导电聚合物的发展历史，导电聚合物的结构特征和基础性能、导电聚合物的类型及其合成方法；然后重点介绍了导电聚吡咯的研究进展。     

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。     

聚吡咯/聚乳酸多孔复合导电材料的制备与表征

以FeCl_3为氧化剂和掺杂剂,以SDS(十二烷基磺酸钠)为乳化剂,利用乳液聚合法制备用于周围神经修复的聚吡咯(PPy)/聚乳酸(PDLLA)多孔复合导电材料。用傅立叶红外光谱,扫描电镜及霍尔效应测试系统对其进行了表征。结果表明:PDLLA的特征吸收峰和PPy的特征吸收峰在复合材料的FI-IR图谱中都有体现。说明复合体系中确有PDLLA和PPy。扫描电镜观察结果表明PPy/PDLLA膜是一个两相系统,PPy粒子分散在连续的绝缘PDLLA相中,并具有多孔结构,导电性能实验表明10%PPy/PDLLA具有最好的导电性。     

聚吡咯／聚硫橡胶导电复合膜的制备与表征

利用带有电活性端基的液体聚硫橡胶与吡咯单体在以三氯乙酸作增溶剂兼支持电解质的乙腈溶液中一步电化学氧化复合，制备了一类新型的聚吡咯／聚硫橡胶导电复合膜。文中讨论了电流密度，吡咯与聚硫橡胶浓度比，电解液温度等制备条件对复合膜导电性的影响，并采用傅里叶变化红外光谱，扫描电镜和热重分析等技术对复合膜进行了表征。     

聚吡咯/凹凸棒石水性导电涂料的制备

用吡咯单体(Py)在凹凸棒石(ATP)的表面发生原位聚合反应,制备出聚吡咯/凹凸棒石(PPy/ATP)纳米导电复合材料.通过Fourier红外光谱、X射线衍射、扫描电子显微镜对复合材料进行表征,结果表明聚吡咯的包覆没有破坏凹凸棒石的晶体结构,两者之间作用仅为物理作用.以PPy/ATP为填料制备的水性丙烯酸涂料导电性高于以PPy为填料制备的水性丙烯酸涂料,并通过SEM研究了涂层的导电机理,表明PPy/ATP在导电涂料中具有更为广阔的应用前景.     

Synthesis and conductive properties of polypyrrole nanocomposites

This paper studies the impact on the different surfactants and capacity of the oxidant for the synthesis of polypyrrole (PPy). The soluble PPy has also been studied. PPy was characterized mainly from the surface morphology, Fourier transform infrared spectroscopy, and conductivity sigma. First, using cetyltrimethylammonium bromide (CTAB) as the surfactant doped in an acid doping environment and without using ammonium persulfate (APS) as an oxidant, we determined the different capacities of the oxidant to synthesize the PPy. Scanning electron microscopy, Fourier transform infrared spectroscopy, and a four-probe conductivity meter were used to characterize the PPy. The acid doping conductivity was found to be 25 S/cm higher. Then, the solubility of polypyrrole was studied by doping with sodium dodecyl benzene sulfonate (SDBS), polyethylene glycol (PEG), and poly(styrene sulfonate) (PSS), proceeding the above-mentioned characterization.     

In situ preparation and mechanical properties of CNTs/MCMBs composites

By adding carbon nanotubes (CNTs) into medium temperature coal tar pitch, mesocarbon microbeads (MCMBs) were obtained via thermal condensation, then CNTs/MCMBs composites were in situ prepared using compression molding. The morphology, structure and mechanical properties of CNTs/MCMBs composites were characterized by optical microscope, digital camera, scanning electron microscope (SEM) and mechanical test machine. Results showed that CNTs were used as the nucleating agent and could inhibit the growth and coalescence of MCMBs. The optical textures of CNTs/MCMBs composites showed similar characteristics to the thermal condensation products from coal tar pitch with CNTs. The mass ratio of CNTs to coal tar pitch played an important role in the mechanical properties of CNTs/MCMBs composites. The density and bending strength of CNTs/MCMBs composite first increased and then decreased with the increase of the proportion of CNTs. When the proportion of CNTs was 5 wt%, the density of the composite reached the maximum (1.76 g/cm³). In addition, the bending strength of the composite reached the maximum (79.6 MPa) as adding 2 wt% CNTs into coal tar pitch.     

In situ preparation, morphology and electrical properties of carbon nanofiber/polydimethylsiloxane nanocomposites

For the first time, a series of carbon nanofiber (CNF)/polydimethylsiloxane(PDMS)-based nanocomposites was prepared using in situ polymerization technique by critical manipulation of factors, such as method of preparation and chemical modification of filler. Quantification of the degree of dispersion was done by introducing a dispersion degree parameter. Extent of dispersion was found to improve by amine modification of CNFs. Electrical conductivity was found to undergo profound increase when compared with that of the insulating base polymer. Amine-modified CNF-based nanocomposites showed percolation threshold at lower filler loading compared with unmodified CNF-based nanocomposites. These results of electrical properties measurements were correlated with the results of TEM analysis.     

Novel silicon carbide/polypyrrole composites; preparation and physicochemical properties

Novel silicon carbide/polypyrrole (SiC/PPy) conducting composites were prepared using silicon carbide as inorganic substrate. The surface modification of SiC was performed in aqueous solution by oxidative polymerization of pyrrole using ferric chloride as oxidant. Elemental analysis was used to determine the mass loading of polypyrrole in the SiC/PPy composites. Scanning electron microscopy showed the surface modification of SiC by PPy. PPy in composites was confirmed by the presence of PPy bands in the infrared spectra of SiC/PPy containing various amounts of conducting polymer. The conductivity of SiC/PPy composites depends on PPy content on the surface. The composite containing 35 wt.% PPy showed conductivity about 2 S cm⁻¹, which is in the same range as the conductivity of pure polypyrrole powder prepared under the same conditions using the same oxidant. PPy in the composites was clearly detected by X-ray photoelectron spectroscopy (XPS) measurements by its N1s and Cl2p peaks. High resolution scans of the C1s regions distinguished between silicon carbide and polypyrrole carbons. The fraction of polypyrrole at the composite surface was estimated from the silicon and nitrogen levels. The combination of XPS and conductivity measurements suggests that the surface of the SiC/PPy composites is polypyrrole-rich for a conducting polymer mass loading of at least 12.6 wt.%.     

纳米银/壳聚糖复合水凝胶的原位制备、表征及抗菌性能研究

在壳聚糖/1,2-丙二醇凝胶中采用抗坏血酸原位还原硝酸银生成纳米银,进而通过碱液置换得到具有不同纳米银含量的物理交联的纳米银/壳聚糖复合水凝胶.紫外-可见光谱、X射线衍射图谱和低分辨率TEM照片的结果表明,复合水凝胶内形成了分散良好的纳米银.高分辨率TEM照片结果表明纳米银的直径在20～50nm之间,但其结晶状态并不均一.抗菌性实验证明,纳米银/壳聚糖复合水凝胶对大肠杆菌和金黄色葡萄球菌均有抗菌效果.     

多层石墨/硅树脂导热复合材料的制备与性能

以硅树脂为基体材料, 多层石墨为导热填料, 采用旋转搅拌球磨法制备了多层石墨/硅树脂导热复合材料, 研究了填料对多层石墨/硅树脂复合材料热导率、 热膨胀系数(CTE)和热稳定性的影响。结果表明, 多层石墨在硅树脂中分散性良好。多层石墨/硅树脂复合材料的热导率随多层石墨填充量的增加而增大, 填充质量分数为45%时, 热导率达到2.26 W·(m·K)^-1, 超过此值之后热导率开始下降。随着填料的增加, 多层石墨/硅树脂复合材料热膨胀系数减小。与纯硅树脂相比, 多层石墨/硅树脂复合材料热稳定性高。相同填充量下多层石墨/硅树脂比SiC/硅树脂、 AlN/硅树脂的热导率高得多, 这说明径厚比大的片状填料更易形成有效接触和导热网链。     

多层石墨/硅树脂导热复合材料的制备与性能

以硅树脂为基体材料,多层石墨为导热填料,采用旋转搅拌球磨法制备了多层石墨/硅树脂导热复合材料,研究了填料对多层石墨/硅树脂复合材料热导率、热膨胀系数(CTE)和热稳定性的影响.结果表明,多层石墨在硅树脂中分散性良好.多层石墨/硅树脂复合材料的热导率随多层石墨填充量的增加而增大,填充质量分数为45％时,热导率达到2.26W· (m· K)-1,超过此值之后热导率开始下降.随着填料的增加,多层石墨/硅树脂复合材料热膨胀系数减小.与纯硅树脂相比,多层石墨/硅树脂复合材料热稳定性高.相同填充量下多层石墨/硅树脂比SiC/硅树脂、AlN/硅树脂的热导率高得多,这说明径厚比大的片状填料更易形成有效接触和导热网链.