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.     

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.     

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.     

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.     

The influence of thermal history on the mechanical properties of poly(ether ether ketone) matrix composite materials

The purpose of this study is to provide insight into the microstructural factors that affect the flexural fatigue performance of carbon-fibre-reinforced poly(ether ehter ketone) (PEEK) composites. Specifically, the effect of the degree of crystallinity on the mechanical properties is examined at two crystallinity levels of the as-received composites (35%) and of quenched composites (10%). Higher static flexural strength and modulus as well as longer fatigue life are observed for the higher crystallinity level. By varying the loading angle with respect to the fibre direction it is shown that the crystallinity effect is not matrix dependent alone. Rather, a strong effect is evident in the fibre direction, which is attributed to the influence of the transcrystalline layer formed on the fibre surface in the high-crystallinity material. As a result, the longitudinal fatigue life at 1·7GPa of the 35% crystallinity material is three orders of magnitude higher than that of the 10% crystallinity composite.     

Effect of carbon nanotubes on the mechanical properties and crystallization behavior of poly(ether ether ketone)

Pristine carbon nanotubes (CNTs) and noncovalently functionalized carbon nanotubes (f-CNTs) were used to prepare poly(ether ether ketone) (PEEK) composites (CNTs/PEEK and f-CNTs/PEEK) via melt blending. Noncovalently functionalized multiwalled nanotubes were synthesized using hydrogen-bonding interactions between sulfonic groups of sulfonated poly(ether ether ketone) (SPEEK) and carboxylic groups of nanotubes treated by acid (CNTs–COOH). The effects of these two kinds of nanotubes on the mechanical properties and crystallization behavior of PEEK were investigated. CNTs improved mechanical properties and promoted the crystallization rate of PEEK as a result of heterogeneous nucleation. Better enhancement of mechanical properties appeared in the f-CNTs/PEEK composites, which is ascribed to the good interaction between f-CNTs and PEEK. However, the strong interaction of f-CNTs and PEEK chains decreased the crystallization rate of PEEK for high content of f-CNTs.     

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.     

含氟聚芳醚酮超疏水涂层及其性能

使用由双酚AF和4,4-二氟二苯甲酮缩聚而得的含氟聚芳醚酮(FPAEK)为树脂基体,以疏水气相SiO₂和碳纳米管(CNT)为无机掺杂纳米粒子,采用一步喷涂法在铝板表面制备了一种SiO₂-CNT/FPAEK超疏水涂层。研究发现,当SiO₂和CNT掺杂量都为1wt%时,所得涂层的超疏水性能最好,其水接触角W_CA可达到167°,滚动角S_A为3°。该涂层的玻璃转化温度和初始分解温度分别达到170℃和480℃,热稳定性优异。将该涂层分别在pH=1的HCl溶液、pH=13的NaOH溶液和质量分数为3.5wt%的NaCl溶液中浸泡13天,W_CA都维持在150°以上,说明具有较好的化学稳定性。经过80个摩擦循环测试后,该涂层的W_CA还维持在151°,说明具有较好的机械稳定性。电化学测试表明,该涂层可以将马口铁的腐蚀电压E_corr从?0.538 V提高到?0.112 V,而腐蚀电流J_corr从2.105×10?5 A下降到1.94×10?7 A,说明具有优异的防腐蚀性能。此外,将基底换成常见的铁板、水泥板、玻璃板和聚乙烯塑料板,同样获得了超疏水涂层。涂层表面的污染物可以被自由滚落的水珠轻易带走,表明涂层具有良好的自清洁性能。可见,所得SiO₂-CNT/FPAEK超疏水涂层具有广阔的应用前景。      

磺化杂萘联苯聚醚酮膜的制备及其阻醇和质子导电性能

采用浓硫酸和发烟硫酸的混合物作磺化剂得到不同磺化度的磺化杂萘联苯聚醚酮（SPPEK）,考察了不同磺化度的SPPEK膜的导电和阻醇特性．磺化度为73％的膜在测试的温度范围内膜的电导率数量级在10^-2S／cm,其甲醇透过系数约比Nafion 115膜低一个数量级,如果以质子传递通量和甲醇传递通量之比定义为综合指标,SPPEK膜的综合性能比Nafion 115膜高3．3倍。     

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%.     

Sulphonated poly(ether ether ketone): Synthesis and characterisation

The sulphonation of commercially available PEEK in powder form (Gatone, Gharda Chemicals Limited, India) was carried out using conc. H²SO⁴ under different reaction conditions. The duration of reaction was varied from 3–5 h, polymer concentration 4–10% (w/v) and temperature 35–50C. Structural characterisation of sulphonated polymers was done by elemental analysis, FT-IR and ¹H-NMR spectroscopy. The degree of sulphonation as calculated from ¹H-NMR and elemental analysis (S-content) was found to be in the range of 50–80%. Multistep mass loss was observed in thermogravimetric traces (recorded in N² atmosphere). The first step (50–225 ± 25C) was due to loss of moisture (1–10%) and second step (250–425 ± 25C) has been attributed to volatilization of SO³ from the sulphonic group. The backbone degradation takes place above 450C. The mechanical properties and proton conductivities of various sulphonated samples was also evaluated.     

含氰侧基联苯型聚芳醚醚酮酮/芳醚醚酮酮共聚物的合成与表征

在无水AlCl3及N-甲基吡咯烷酮(NMP)/1,2-二氯乙烷(DCE)复合溶剂的存在下,将2,6-二苯氧基苯甲腈(DPOBN)与4,4’-二氯甲酰基联苯(BClBP)及对苯二甲酰氯(TPC)进行三元低温共缩聚反应,合成了一系列含氰侧基联苯型聚芳醚醚酮酮/芳醚醚酮酮共聚物。用IR、DSC、TG、WAXD及元素分析等方法对其结构和性能进行了表征。结果表明,所合成的聚合物具有预期结构且均为非晶态聚合物;其玻璃化转变温(Tg)度为180~196℃,在N2气氛中热分解5%的温度(Td)为495~508℃,具有突出的耐高温性能。     

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.     

磺化杂萘联苯聚醚酮酮质子交换膜材料的合成与性能

以4-(4-羟基苯基)-2,3-二氮杂萘-1-酮(DHPZ)、1,4-二(3-磺酸钠基-4-氟代苯甲酰基)苯(SBFBB)和1,4-二(4-氯代苯甲酰基)苯(BCBB)为原料,经高温溶液缩聚反应,成功制备了一系列不同磺化度的新型杂萘联苯聚醚酮酮(SPPEKKs).利用FT-IR和1H-NMR对聚合物结构进行表征.采用溶液浇铸法制备了聚合物薄膜.测定了膜的吸水率,溶胀率,离子交换容量,耐氧化性和质子传导率.结果表明该系列磺化杂萘联苯聚醚酮酮膜具有良好的抗氧化性和较高的质子传导率.     

含有叔胺结构的聚醚醚酮单体的合成

通过三步反应合成了一种具有叔胺结构的聚醚醚酮单体,其结构经1H NMR1、3CNMR、IR和元素分析确证,同时讨论了影响反应的因素。     

聚芳醚酮改性酚醛树脂复合材料的制备及性能研究

采用热塑性聚芳醚酮(PAEK)与环氧树脂制得预聚体,并用预聚体改性酚醛树脂,起到增韧作用.通过红外光谱、综合热分析和力学性能测试对复合材料进行性能表征.研究结果表明,材料的韧性和热性能对PAEK的含量有一定的依赖性.红外光谱分析表明,PAEK固化过程中没有参与反应;热分析表明,改性的酚醛树脂复合材料的耐热性良好,最高热分解温度为525℃.