导电高分子材料的应用和进展

论述了复合型及结构型导电高分子材料的导电机理、应用和研究进展。     

导电聚苯胺呋喃的结构表征

碘掺杂聚苯胺呋喃是一类非共轭导电聚合物。用紫外吸收光谱、傅里叶变换红外吸收光谱、电子顺磁共振波谱、光电子能谱等对该聚合物的结构性质及导电机制进行了研究。     

聚并苯导电高分子材料研究的进展

聚并苯导电材料可由酚醛树脂高温裂解得到,其比重、磁化率、电阻率等在50年代就有人进行过研究。80年代以来,随着有机导电聚合物研究的兴起,聚并苯材料以其合成简单、易于掺杂、在空气中稳定及电导率可随合成温度变化(近20个数量级)等特点引起了人们极     

气相氧化聚合制备聚合物／聚吡咯表面复合导电材料

将填充有ＦｅＣｌ３的苯乙烯－丙烯腈共聚物，用ＦｅＣｌ３的乙醇溶液浸泡处理后，置于吡咯气氛中，制得聚合物／聚吡咯表面复合导电材料。研究了苯乙烯－丙烯腈中ＦｅＣｌ３含量，ＦｅＣｌ３／乙醇溶液浓度，浸泡时间，聚合反应时间对材料电导率的影响。用扫描电镜观察了导电层的表面结构并测定了导电性的稳定性。导电材料最高电导率达４．８×１０３Ｓ·ｍ－１，在干燥气氛下可稳定１８个月以上。     

本征导电聚合物涂层及界面

本文结合我们实验研究结果及国外最近的研究进展，对在绝缘基质的表面本征导电聚合物涂层的形成、结构和性能作了扼要的分析，指出了化学反应法中通过单体向整体聚合物表层扩散聚合形成的导电膜、界面的偶联作用和电荷转移作用等几种新近证实的原理，在加速导电聚合物涂层的应用中，具有重要意义。     

还原态卤代聚苯胺能带结构及掺杂导电机理的研究

用ＥＨＭＯ－ＣＯ方法研究了卤代聚苯胺的能带结构及其掺杂导电机理，结果表明，在掺杂态卤代聚苯胺中形成单极化子晶格；取代主要通过改变带宽影响电导率，由掺杂而大幅度地提高了电导率是因为大大缩小了带隙，并进一步证实了外层ｄ轨道的成键作用。     

一种高透明、可拉伸导电水凝胶的制备及其在电容传感器中的应用

导电水凝胶由于具备良好的电学特性、可调节的机械性能、易于加工性和生物相容性等,是制备柔性电子设备的理想基材。本文使用马来酸与丙烯酰胺作为共聚单体,氯化锂作为导电离子,N,N'-二甲基双丙烯酰胺作为交联剂,使用光引发剂,采用原位光聚合的方式制备了一种导电水凝胶。制得的水凝胶可见光透过率高达93%,最大拉伸形变~380%,导电率最大为12 S/m。鉴于其优异的综合性能,实验中使用导电水凝胶制备了电容传感器并应用于人体活动监测。结果表明,制备的导电水凝胶电容传感器对不同程度的手指弯曲形变和不同力度的手指触碰均表现出灵敏的响应行为,为未来可穿戴柔性电子产品的发展起到了一定的推动作用。     

导电复合材料中的双逾渗行为及其应用

综述了炭黑粒子填充聚合物复合材料中双逾渗行为的形成机理，炭黑粒子的分布状况及双逾渗行为的应用。     

季铵盐型离子导电聚合物的研究

对聚苯胺呋喃季铵盐的物理性质及导电机制进行了分析讨论。结果表明，所制备的季铵盐最高电导率可达１０＾－４Ｓ·ｃｍ＾－１量级，其导电性随季铵化程度增加而增加，温度、湿度对其导电性有较大的影响；在环境温度、湿度基本恒定的条件下，季铵盐有较好的电导稳定性。此季铵盐是通过离散的阴离子而传导，通过链段运动传输电荷。     

一种提高有机硅导电橡胶复合材料导电和电磁屏蔽性能的方法

描述了一种利用多元复合导电网络提高有机硅橡胶复合材料导电和电磁屏蔽性能的思想。这种含有多元复合导电网络的复合材料是通过将镀银泡沫、导电填料和有机硅橡胶复合在一起而制备的。利用扫描电子显微镜观察了复合材料的微观结构,采用电阻测试仪、矢量网络分析仪、热失重分析仪分别研究了复合材料的导电性、电磁屏蔽性能及热稳定性,并探讨了补强剂SiO2对这些性能的影响。结果表明,2%碳纳米管/导电泡沫/硅橡胶多元复合体系相比于2%碳纳米管/硅橡胶单一复合体系电阻率降低了6个数量级,平均电磁屏蔽效能由12dB提高到52dB,增大了4倍。当导电填料换为炭黑后,2%炭黑/导电泡沫/硅橡胶多元复合体系相比于2%炭黑/硅橡胶单一复合体系电阻率降低了7个数量级,平均电磁屏蔽效能由10dB提高到50dB,增大了5倍。由于多元复合导电网络,材料的导电性能和电磁屏蔽性能大幅度提升。此外,补强剂的加入增大了复合材料的热稳定性,但降低了其导电和电磁屏蔽性能。     

填充粒子对复合型导电硅橡胶电阻温度特性的影响

研究了炭黑填充复合型导电硅橡胶的电阻温度特性,分析了升温过程中导电硅橡胶电阻特性的详细变化过程。研究了导电粒子和白炭黑含量对导电硅橡胶电阻温度特性的影响,测量了在不同热处理温度下电阻率的变化及加力时电阻的驰豫时间。分析了热处理对电阻特性影响的机理。     

加成型液体硅橡胶的研究进展

结合加成型液体硅橡胶的硫化原理,综述了加成型液体硅橡胶导热性能、耐高温性能及粘结性能的最新研究进展,发现加入金属氮化物导热填料是提高加成型液体硅橡胶导热性能的有效途径;改善分子结构是提高加成型液体硅橡胶耐高温性能的主要途径;共混粘结促进剂是提高加成型液体硅橡胶粘结性能的重要途径。介绍了加成型液体硅橡胶的最新应用领域,提出功能化加成型液体硅橡胶,如3D个性化打印硅橡胶、人体器官硅橡胶、高折光封装硅橡胶等功能材料是未来加成型液体硅橡胶的发展方向。     

Improving Elasticity of Conductive Silicone Rubber by Hollow Carbon Black

Carbon black-based conductive rubber composites have important impacts on electromagnetic interference(EMI) shielding applications. However, an excessive amount of carbon black in the recipes of these conductive rubbers has caused their weak elasticity. Herein, hollow carbon black(HCB) particles were used to tune the elasticity of conductive rubber composites. Unique hollow morphology produced a better compression recovery of HCB than other solid carbon black, such as acetylene black. When the coupling agent was bonded to HCB, their conductive silicone rubber composites were featured by high stretching resilience, a fast compression recovery and excellent conductivity to satisfy the electromagnetic interference shielding requirements. Importantly, the rubber composites with coupling HCB had extremely low variations of mechanical property, conductivity and EMI shielding effectiveness after thermal accelerated aging tests. It is therefore revealed that the elasticity of HCB and its interfacial chemical coupling with rubber chains both play crucial roles in adjusting the elasticity of conductive rubber to sever long-term EMI protection.     

Bubble-templated Construction of Three-dimensional Ceramic Network for Enhanced Thermal Conductivity of Silicone Rubber Composites

With the continuous development of the electronics industry, the energy density of modern electronic devices increases constantly,thus releasing a lot of heat during operation. Modern electronic devices take higher and higher request to the thermal interface materials.Achieving high thermal conductivity needs to establish an interconnecting thermal conductivity network in the matrix. For this purpose, the suspension of Al_2 O_3 and curdlan was first foamed to construct a bubble-templated continuous ceramic framework. Owing to the rapid gelation property of curdlan, we can easily remove moisture by hot air drying. Finally, the high thermally conductive composites are prepared by vacuum impregnation of silicone rubber. The result showed that composites prepared by our method have higher thermal conductivity than the samples obtained by traditional method. The thermal conductivity of the prepared composite material reached 1.253 W·m~(–1)·K~(–1) when the alumina content was 69.6 wt%. This facile method is expected to be applied to the preparation of high-performance thermal interface materials.     

Thermal characterization of Al2O3 and ZnO reinforced silicone rubber as thermal pads for heat dissipation purposes

Silicone rubber filled with thermally conductive, but electrically insulating Al₂O₃ or ZnO fillers were investigated to be used as elastomeric thermal pads, a class of thermal interface materials. The effect of Al₂O₃ or ZnO fillers on the thermal conductivity and coefficient of thermal expansion (CTE) of the silicone rubber were investigated, and it was found that with increasing Al₂O₃ or ZnO fillers, the thermal conductivity of the thermal pads increases, while the coefficient of thermal expansion (CTE) decreases. The thermal conductivity results obtained were also analyzed using the Agari model to explain the effect of Al₂O₃ or ZnO fillers on the formation of thermal conductive networks. Thermal gravimetry analysis (TGA) showed that the addition of either Al₂O₃ or ZnO fillers increases the thermal stability of the silicone rubber, while the scanning electron microscope (SEM) showed that at 10 vol.% filler loading percolation threshold has yet to be reached.     

Relaxation behavior of methacrylic polymers with bulky hydrophilic groups in their structures

The isochrones showing the temperature dependence of the loss relaxation modulus of poly(neopentyl glycol methacrylate) present an ostensible subglass absorption called β relaxation that roughly has the same intensity as the glass–rubber relaxation, or α process. The dielectric relaxation spectrum of this polymer also exhibits a well-developed β process followed at higher temperatures by the glass–rubber, or α relaxation, which strong conductive effects only permit to be detected at high frequencies. A detailed study of the conductive contributions to the dielectric loss above T_g was carried out using a theory that assumes that the dispersion observed in tan δ in the frequency domain arises from the Maxwell–Wagner–Sillars effect combined with Nernst–Planck electrodynamic effects caused by interfacial polarizations in the interface polymer electrodes. Attempts were made to evaluate the equivalent salt concentration that would produce the conductive effects experimentally observed. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 3027–3037, 1999     

聚苯胺/顺丁橡胶复合导电膜的制备与性能

采用溶液共混与浇铸法制备聚苯胺（PAn ）/顺丁橡胶（BR）复合导电膜,确定了本征态聚苯胺以顺丁橡胶为弹性基体材料,甲苯为溶剂,过氧化二苯甲酰为交联剂,十二烷基苯磺酸作为共混分散剂和聚苯胺掺杂剂的复合膜制备工艺,并对复合膜的导电性能和形态结构进行了测试与表征.     

聚氯乙烯表皮成分对加成型硅橡胶固化的影响

采用流变学方法研究了双组分加成型硅橡胶在不同聚氯乙烯(PVC)表皮上的固化动力学,并利用红外光谱、核磁共振波谱、电感耦合等离子体质谱仪等手段分析了PVC表皮成分,以确定导致双组分加成型硅橡胶不固化的具体原因。 结果表明,PVC表皮中导致硅橡胶不固化的主要元素为P元素。 在固定硅橡胶厚度为1 mm的情况下,当PVC表皮中的P元素质量分数低于3×10^-3%时,浇注在其上的双组分加成型硅橡胶依然能固化;而当PVC表皮中的P元素质量分数超过约2.4×10^-2%时,虽然浇注在其上的双组分加成型硅橡胶的中间层依然能固化,但与PVC表皮接触部分的硅橡胶不固化,且不固化层厚度随P元素质量分数增加而增加。 本文还研究了在P元素质量分数低于3×10^-3%的PVC表皮上,降低硅橡胶厚度至微米级时的固化行为,在P元素质量分数低于3×10^-3%的PVC表皮上,当硅橡胶厚度低于2 μm时,硅橡胶出现不完全固化现象。 双组分加成型硅橡胶在含有P元素的PVC表皮表面的固化行为主要是由硅橡胶样品中铂催化剂总含量及PVC表皮中的P元素含量确定的,同时也会受到双组分加成型硅橡胶反应速率以及铂催化剂、P元素在硅橡胶中的扩散速率的影响。     

剥离型硅橡胶/黏土纳米复合材料研究

利用层状硅酸盐制备有机 无机纳米复合材料是当前人们研究的热点[1,2 ] ,这类材料具有较常规聚合物 无机填料复合材料无法比拟的优点 ,可以明显改善高分子材料的物理机械性能、热稳定性、气体阻隔性、阻燃性、导电性、光学性等 .一般来说 ,聚合物 层状硅酸盐 (Ｐｏｌｙｍｅｒｌａｙｅｒｅｄｓｉｌｉｃａｔｅ ,ＰＬＳ)纳米复合材料可分为插层型和剥离型两种类型 .插层型纳米复合材料即聚合物插入到硅酸盐层中 ,硅酸盐在近程仍保持原有的有序晶体结构 ,在远程则是无序的 .对弹性体而言 ,硅酸盐含量在插层型杂化材料中的含量比较高 ,力学性能…     

阻燃及可瓷化硅橡胶成炭结构的研究进展

简单介绍了硅橡胶的阻燃和瓷化机理。依据阻燃剂、填料及炭层结构的不同,将硅橡胶分为阻燃和可瓷化两大类.综述了阻燃硅橡胶和可瓷化硅橡胶的阻燃性能和成炭结构的研究进展。分析表明:添加物理或化学膨胀型阻燃剂的硅橡胶,燃烧过程中形成的炭层疏松多孔,阻燃隔热性能优异,但炭层强度差;添加非膨胀型阻燃剂的硅橡胶,炭层结构相对密实,但表面不平整,存在孔洞和裂缝,阻燃效果不好;添加可瓷化填料的硅橡胶燃烧形成的陶瓷炭层坚硬而致密,具有优异的耐火持久性,但在隔绝热量方面不如膨胀炭层。炭层的疏松隔热与坚固耐久兼顾是阻燃硅橡胶未来可能的发展方向。