磺化聚醚醚酮/多壁碳纳米管复合质子交换膜的制备与性能

合成了表面接枝磺酸基团的改性多壁碳纳米管(S-MWNTs),通过溶液共混法制备了用于直接甲醇燃料电池的磺化聚醚醚酮(SPEEK)/S-MWNTs复合膜.扫描电镜显示,SMWNTs在掺杂量比较少时,能够在SPEEK基体中均匀分散;热重分析证明,复合膜具有优异的热稳定性.当掺杂量为1%时,复合膜的机械性能,尺寸稳定性及电导率均提高,这有效解决了纯SPEEK膜中质子电导率与机械性能、尺寸稳定性等相矛盾的问题.     

SPEEK/PEI@ILs复合质子交换膜的制备及PEMWE性能

以磺化度为75%的磺化聚醚醚酮(SPEEK)为原料,加入聚醚酰亚胺(PEI)和离子液体(ILs)制备SPEEK/PEI@ILs酸碱复合膜用于质子交换膜电解水制氢(PEMWE)中.研究复合膜的吸水率、溶胀度、质子电导率、热稳定性和相应的PEMWE性能.结果表明,SPEEK/PEI@ILs复合膜与商业Nafion117膜相比,具有相近的质子电导率和溶胀度,说明PEI的加入,增强了复合膜的尺寸稳定性.将SPEEK/PEI@ILs复合膜制备成膜电极并测试PEMWE性能,1 A/cm²电流密度下槽电压为2.75 V,在0.5 A/cm²@1.96(±0.03)V条件下能稳定运行10 h.     

SPEEK/SiO2复合型质子交换膜的结构与性能

以磺化聚醚醚酮(SPEEK)为基体,通过溶胶-凝胶法制得了SPEEK/SiO2复合质子交换膜,采用扫描电镜、交流阻抗和热重分析等方法研究了复合膜的结构与性能。结果表明,SiO2与SPEEK之间的共价交联使两相间的相容性得到明显的改善,SiO2粒子以纳米尺寸均匀地分散在聚合物基体中。SiO2粒子的掺入使得复合膜的质子传导性能略有降低,但复合膜中SPEEK-SiO2-SPEEK这种共价交联结构的生成使膜的阻醇性能和溶胀性能得到了明显提高,热稳定性也有所提高。     

基于P_2O_5/SiO_2与磺化聚醚醚酮合成的无机/有机复合质子交换膜

采用溶胶-凝胶法制备P2O5/SiO2溶胶与P2O5/SiO2粉末,之后分别与磺化聚醚醚酮(SPEEK)复合,制得无机/有机复合质子交换膜并研究了两种膜的形貌、力学性能以及质子电导率。与纯SPEEK膜相比,P2O5/SiO2无机成分的引入能显著改善复合膜的质子导电性能。同时,P2O5/SiO2的不同引入方式导致复合膜具有不同的结构,进而引起复合膜力学性能与质子导电性能上的差异。在所制备的无机/有机复合膜中,含有40%P2O5/SiO2(质量分数)粉末的复合膜的质子电导率达到1.6×10-2 S/cm,其所组装的单电池的开路电压为0.95V,峰值功率密度达到446mW/cm2。     

硅烷偶联剂改性钛酸钡对SPEEK质子交换膜性能的影响

为提高无机填料在聚合物中的分散性,利用硅烷偶联剂KH570对钛酸钡(BT)表面改性.采用溶液浇铸法制备磺化聚醚醚酮(SPEEK)/改性BT(KH570-BT)复合质子交换膜.利用透射电镜观察了改性前后BT在SPEEK基体中的分散情况并系统研究了KH570-BT掺杂量对复合质子交换膜性能的影响.结果显示,与BT相比,KH570-BT的分散性得到明显改善.将KH570-BT掺杂进SPEEK后,复合膜的质子电导率、甲醇渗透率、热稳定性及选择性均出现明显提升.室温下,SPEEK/KH570-BT-1.0复合膜的质子电导率达到63.7 mS/cm,高于同配比的SPEEK/BT-1.0(σ=57.7 mS/cm)和SPEEK(σ=58.6 mS/cm);SPEEK/KH570-BT-1.0的选择性达到20.9×10~4 S·s/cm~3,与SPEEK/BT-1.0(17.2×10~4 S·s/cm~3)和SPEEK(17.7×10~4 S·s/cm~3)相比,分别提升了21.5%和18.1%.     

疏水性纳米SiO2填充PDMS/PET复合膜的制备及分离性能研究

采用聚酯(PET)为支撑层,以疏水性气相法纳米SiO2填充改性的聚二甲基硅氧烷(PDMS)为皮层制备硅橡胶复合膜,用SEM、WSM-5 KN、TGA对膜改性后的物理形貌、拉伸强度及热稳定性进行分析与表征,并以乙醇/水物系为研究对象,着重考察了料液温度和浓度对改性复合膜渗透分离性能的影响.结果表明,改性膜的热稳定性显著提高,拉伸强度从空白膜的1.5 MPa增加到7.4 MPa.随着疏水气相法纳米SiO2含量的增加填充膜的分离因子极值不断增加并提前.     

磺化聚醚醚酮/蒙脱土复合型质子交换膜制备与性能

以磺化聚醚醚酮(SPEEK)为基体,以有机改性的蒙脱土(OMMT)为无机相,采用溶液插层法成功制备出了可望应用于直接甲醇燃料电池的SPEEK/OMMT复合型质子交换膜.通过X射线衍射(XRD)表征了复合膜的微观结构,并采用交流阻抗和隔膜扩散方法分别考察了复合膜的质子传导性能和阻醇性能.结果表明,蒙脱土的片层间距超过4.4 nm,SPEEK高分子链已插层到蒙脱土片层之间.与纯SPEEK膜相比,SPEEK/OMMT复合膜的质子传导率有所降低,但在90℃也达到了1.2×10-2S/cm的水平,而且蒙脱土的加入明显地降低了SPEEK膜的甲醇渗透率.     

DMFC用磺化聚醚醚酮/聚苯胺共混型质子交换膜的研究

磺化聚醚醚酮膜(SPEEK)是直接甲醇燃料电池(DM FC)用质子交换膜的候选材料之一,但是当温度和磺化度(D S)较高时,该膜在甲醇水溶液中溶胀非常严重,甚至溶解,其使用温度受到限制。将磺化度为50.11%的SPEEK和聚苯胺(PAN I)共混制膜,希望利用酸碱之间的相互作用对SPEEK进行改性。研究结果表明,PAN I的加入使SPEEK/PAN I共混膜的使用温度有较大提高,并且该膜还具有较高的电导率和较好的阻醇性能。     

直接甲醇燃料电池用磺化聚醚醚酮质子交换膜

在回顾近年来直接甲醇燃料电池用磺化聚醚醚酮(SPEEK)质子交换膜的发展历程基础上,分别综述了制膜材料SPEEK的合成和SPEEK质子交换膜的制备研究进展,重点总结了SPEEK质子交换膜的电导率和阻醇性能及其稳定性的影响因素和影响规律,其中包括制膜材料和溶剂以及工艺、SPEEK的共混改性、SPEEK的填充改性或多层复合结构的影响,进而分析了高性能SPEEK质子交换膜的开发研究前景.     

测试介质对纳米CeO_2改性SPEEK膜质子电导率的影响

采用纳米氧化铈(CeO2)改性磺化度48.3%的磺化聚醚醚酮(SPEEK),通过溶液浇铸法制备用于直接甲醇燃料电池的质子交换膜.在两种介质中测试改性膜的电导率均随温度的升高而增大,与未改性膜相比却大小正好相反:在1 mol/L以盐酸溶液为电解液的测试介质中,改性膜的电导率是未改性膜的15倍,在水蒸气测试介质中,却仅为40%.红外光谱分析表明,CeO2中的铈原子与—SO3H基团中的氧原子发生配位作用.X射线衍射仪(XRD)分析可见,当复合膜浸入1 mol/L盐酸4 h前后,纳米CeO2的晶体结构未见明显变化,表明所发生的配位作用仅处于CeO2和SPEEK两个固相界面上.扫描电子显微镜(SEM)观察改性膜和未改性膜均无网络结构和微相分离,质子在膜内通过—SO3H基团之间的跃迁传导,酸溶液介质远比水蒸气有利于质子在纳米CeO2改性SPEEK膜内磺酸基团之间的跃迁.     

Carbon-nanofibre-reinforced poly(ether ether ketone) composites

Poly(ether ether ketone) nanocomposites containing vapour-grown carbon nanofibres (CNF) were produced using standard polymer processing techniques. Evaluation of the mechanical composite properties revealed a linear increase in tensile stiffness and strength with nanofibre loading fractions up to 15 wt% while matrix ductility was maintained up to 10 wt%. Electron microscopy confirmed the homogeneous dispersion and alignment of nanofibres. An interpretation of the composite performance by short-fibre theory resulted in rather low intrinsic stiffness properties of the vapour-grown CNF. Differential scanning calorimetry showed that an interaction between matrix and the nanoscale filler could occur during processing. Such changes in polymer morphology due to the presence of a nanoscale filler need to be considered when evaluating the mechanical properties of such nanocomposites.     

Carbon-nanofibre-reinforced poly(ether ether ketone) fibres

Nano-reinforced fibres were spun from a semicrystalline high-performance poly(ether ether ketone) containing up to 10 wt% vapour-grown carbon nanofibres using conventional polymer processing equipment. Mechanical tensile testing revealed increases in nanocomposite stiffness, yield stress, and fracture strength for both as-spun and heat-treated fibres. X-ray and differential scanning calorimetry analyses were performed in order to investigate both the orientation of nanofibres within the polymer matrix and the matrix morphology. The carbon nanofibres were found to be well aligned with the direction of flow during processing. Significantly, the degree of crystallinity of the poly(ether ether ketone) matrix was found to increase with the initial addition of nanofibres although the crystal structure was not affected. The measured increase in composite tensile modulus is compared to injection-moulded nanocomposite samples made from the same blends. The results highlight the need to characterise the matrix morphology when evaluating nanocomposite performance and hence deducing the intrinsic properties of the nanoscale reinforcement.     

Phase behaviour and mechanical properties of poly(ether ether ketone)-poly(ether sulphone) blends

The phase behaviour and the mechanical properties of binary blends composed of poly(ether ether ketone) and poly(ether sulphone) have been studied both in the amorphous state and after crystallization of poly(ether ether ketone).Differential scanning calorimetry and dynamical mechanical analysis clearly show the existence of phase separation in the blends. Density measurements confirm the absence of strong interactions between the blend components, as well as the slight effect of PES on the crystallization of PEEK.The mechanical properties of the quenched, amorphous blends remain surprisingly good in spite of the observed immiscibility, however, slowly cooled, crystalline blends appear as brittle materials.     

聚醚醚酮改性研究进展

聚醚醚酮(PEEK)作为一种新型高性能热塑性工程塑料,在许多工程领域有着广泛的应用.采用不同手段增强PEEK,改善其加工性能和力学性能、热性能、摩擦学性能,有利于降低材料成本和进一步拓展应用范围.本文从纤维增强PEEK、颗粒填充PEEK、PEEK表面改性、与聚合物共混等方面综述了PEEK改性研究的进展情况.     

聚醚醚酮增韧改性环氧树脂

采用共混法用聚醚醚酮(PEEK)改性环氧树脂(EP),借助差示扫描量热分析(DSC)确定了环氧树脂的固化工艺,测试了共混体系的工艺性能,研究了聚醚醚酮含量对环氧树脂力学性能的影响。借助扫描电子显微镜(SEM)对材料断裂面的形态结构进行了分析,探讨了体系的形态结构与冲击性能之间的关系。结果表明,在改性材料的韧性有所提高的同时,压缩强度、马丁耐热都没有降低。从断裂面的形态来看,是属于韧性断裂。当PEEK的加入量为6%时,韧性最好,达到19．1kJ/m~2,比纯的环氧树脂增加了107．6%。     

聚醚醚酮增韧改性环氧树脂

采用共混法用聚醚醚酮(PEEK)改性环氧树脂(EP),借助差示扫描量热分析(DSC)确定了环氧树脂的固化工艺,测试了共混体系的工艺性能,研究了聚醚醚酮含量对环氧树脂力学性能的影响.借助扫描电子显微镜(SEM)对材料断裂面的形态结构进行了分析,探讨了体系的形态结构与冲击性能之间的关系.结果表明,在改性材料的韧性有所提高的同时,压缩强度、马丁耐热都没有降低.从断裂面的形态来看,是属于韧性断裂.当PEEK的加入量为6%时,韧性最好,达到19.1 kJ/m2,比纯的环氧树脂增加了107.6%.     

聚醚醚酮复合材料的研究进展

复合改性是进一步提高聚醚醚酮(PEEK)使用性能、扩展其应用领域的重要途径.本文综述了PEEK在热机械性能、摩擦学性能等方面的复合改性研究进展,以及PEEK复合材料在生物假体材料领域、磺化PEEK复合材料在质子交换膜领域的应用研究进展.     

The mechanical properties of insert-molded poly (ether imide) (PEI)/C fiber poly (ether ether ketone)(PEEK) composites

The mechanical properties of insert-molded poly(ether imide) (PEI)/carbon fiber poly(etheretherketone) (CF PEEK) have been examined. Bimaterial composite specimens were constructed by injecting CF PEEK into a mold containing one-half of a PEI tensile specimen. These PEI/CF PEEK composites retained much of their strength and dimensional integrity at temperatures as high as 200°C. Variations in test speed had little affect on breaking strains or stiffness. For two grades of PEI examined, properties were independent of the molecular weight of the PEI. Ultimate properties and fracture surfaces suggested good adhesion between the PEI and CF PEEK, possibly aided by miscibility between the two materials. The PEI/CF PEEK bimaterial composites behaved similarly to PC/CF PEEK specimens, but exhibited higher breaking stresses and moduli, both at room and elevated temperatures.     

Thin film and bulk deformation behaviour of poly(ether ether ketone)/poly(ether imide) blends

The deformation behaviour of amorphous thin films of poly(ether ether ketone) (PEEK)/poly(ether imide) (PEI) blends was investigated over a wide temperature range by optical and transmission electron microscopy. All the materials showed localized shear deformation at temperatures well below Tg. In pure PEI and in blends with up to 60 wt% PEEK content, a transition from shear deformation to disentanglement crazing occurred as the temperature was raised. However, this transition was absent in PEEK, which deformed by shear over the whole temperature range, and similar behaviour was found for PEI/80 wt% PEEK. It is argued that at high PEEK content disentanglement crazing is suppressed by strain-induced crystallization and some evidence for crystalline order in deformed regions of initially amorphous PEEK thin films was obtained by electron diffraction. The thin film deformation behaviour of the blends was also shown to be consistent with their bulk deformation behaviour, a high temperature ductile–brittle transition being observed at low PEEK content in tensile tests. This revised version was published online in November 2006 with corrections to the Cover Date.