Preparation and gas permeation of composite carbon membranes from poly(phthalazinone ether sulfone ketone)

Composite carbon membranes were prepared from poly(phthalazinone ether sulfone ketone) (PPESK) by incorporating with polyvinylpyrrolidone (PVP) or zeolite (ZSM-5) through stabilization and pyrolysis processes. The thermal stability of composite polymeric membranes was measured by thermal gravimetric analysis. The resultant composite carbon membranes were characterized by scanning electron microscopy, X-ray diffraction and gas permeation technique, respectively. The results illustrated that the thermal stability of composite polymeric membranes was enhanced by addition of ZSM-5 or reduced by PVP. For ZSM-5 or PVP composite carbon membranes prepared at 650 °C, the O₂ permeability is 199.70 Barrer or 124.89 Barrer, and the O₂/N₂ selectivity is 10.3 or 4.2, respectively. Compared with carbon membranes from pure PPESK, the O₂ permeability of ZSM-5 or PVP composite carbon membranes increases by 18.5 or 11.6 times, together with the O₂/N₂ selectivity decreasing by 35.2% or 73.6%, respectively. The gas separation mechanism of composite carbon membranes is molecular sieving. Adsorption effect also plays a significant role for CO₂ permeating through ZSM-5 composite carbon membranes.     

Segmental dynamics of functional graphene‐filled poly(ether sulfone ether ketone ketone) nanocomposites

The segmental dynamics of functional graphene (fGR)/poly(ether sulfone ether ketone ketone) (PESEKK) nanocomposites were investigated via differential scanning calorimetry and dynamic mechanical analysis (DMA) measurements. First, fGR was prepared using graphene oxide and sodium dodecylbenzene sulfonate. Subsequently, a series of fGR/PESEKK nanocomposites were prepared through solution blend. When the sulfone groups were introduced into the segments of PESEKK polymers, the glass transition temperature (T_g) of PESEKK was higher than that of free sulfone functionalized poly(ether ketone ketone). The fGR/PESEKK nanocomposites displayed a uniform nanostructure because of the strong interfacial interaction between fGR and PESEKK. With the increase in the fGR contents, the T_g values of fGR/PESEKK nanocomposites decreased. Two loss factor peaks were noted in the fGR/PESEKK nanocomposites, which were characterized via DMA. The α′‐relaxation of the nanocomposites at low temperature was assigned to polymer chains close to the polymer/filler interface with mobility higher than that in the bulk unfilled PESEKK (α‐relaxation). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44391.     

新型聚芳醚腈固化邻苯二甲腈树脂的研究

通过两步一锅法制备了氨基封端的新型杂萘联苯聚芳醚腈（A-PPEN）,其具有比常用的芳香二胺固化剂4,4′-二氨基二苯砜（DDS）更为优异的热稳定性。采用差示扫描量热法（DSC）研究了A-PPEN对间苯二酚基邻苯二甲腈树脂前体（DPPH）的固化过程,结果显示该固化体系具有自催化固化的特征,A-PPEN的投料比会影响体系的固化活性。另外研究了该固化体系的流变特性和热稳定性,结果表明树脂的5%热失重温度（T_d5%）最高可达552.9℃,800℃时残炭率（C_y800）为78.6%,最低黏度可至0.06 Pa·s,具有优异的热稳定性和较宽的加工温度窗口。     

Synthesis and properties of novel poly(phthalazinone ether ketone ketone)

A novel poly(phthalazinone ether ketone ketone) was prepared via the nucleophilic substitution polycondensation of bis-1,4-(4-chlorobenzoyl)benzene and 4-(4-hydroxyphenyl)-2,3-phthalazin-1-one. The synthesized polymer exhibited high glass-transition temperature, excellent thermooxidative properties, and fair rheological properties. The polymer was soluble in some polar solvents. Electronic friction and membrane properties are also discussed. The results indicate that the polymer falls in the class of high temperature resistance engineering plastics. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 823–826, 2001     

Interfacial adhesion of plasma‐treated carbon fiber/poly(phthalazinone ether sulfone ketone) composite

Interfacial adhesion between fiber and matrix has a strong influence on composite mechanical performance. To exploit the reinforcement potential of the fibers in advance composite, it is necessary to reach a deeper understanding on the relation between fiber surface treatment and interfacial adhesion. In this study, air plasma was applied to modify carbon fiber (CF) surface, and the capability of plasma grafting for improving the interfacial adhesion in CF/thermoplastic composite was discussed and also the mechanism for composite interfacial adhesion was analyzed. Results indicated that air plasma treatment was capable of increasing surface roughness as well as introducing surface polar groups onto CF; both chemical bonding and mechanical interaction were efficient in enhancements of interlaminate shear strength of CF/PPESK composite, while mechanical interaction has a dominant effect on composite interfacial adhesion than chemical bonding interaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

低截留分子质量新型聚芳醚腈酮超滤膜的研制

以新型聚芳醚腈酮为膜材料 ,以N -甲基 - 2 -吡咯烷酮 (NMP)为溶剂 ,研究了聚合物浓度、添加剂种类及含量、凝胶浴温度等对超滤膜性能的影响。结果表明 ,聚合物质量分数以 1 2 %～ 1 3 %为合适的制膜浓度 ,以聚乙二醇PEG - 4 0 0为添加剂时获得了高截留率和高水通量的超滤膜。随着凝胶浴温度的升高 ,水通量明显增大 ,而截留率有所下降 ,而共聚物的浓度增加则有相反的效果。制得的超滤膜具有较低的截留分子量 (PEG- 2 0 0 0 ) ,将制得的超滤膜用于达旦黄、黄X-G等染料的分离 ,截留率均达 90 %以上     

Improved interfacial adhesion in carbon fiber/poly (ether ether ketone) composites with the sulfonated poly (ether ether ketone) sizing treatment

A water-soluble sulfonated poly (ether ether ketone) (SPEEK) sizing agent is prepared and applied to improve the interfacial adhesion of carbon fiber/poly (ether ether ketone) (CF/PEEK) composites. The surface morphology, surface roughness, surface chemistries, and surface free energy of SPEEK sized CF are obtained to understand the sizing effect. The results reveal the increased surface free energy and surface roughness of SPEEK sized CF. In addition, a chemical reaction between the CF surface and sizing layer is proved based on the results of XPS, IR, and ¹H NMR. The interfacial structure of CF/PEEK composites is further ascertained by AFM and the appearance of gradient interface could be verified for SPEEK sized CF/PEEK composites. The formation of the gradient interface is due to the chemical reaction between the CF and sizing agent as well as the improved compatibility between the sized CF and matrix, which benefits the improvement of interfacial adhesion.     

Preparation of poly(phthalazinone ether sulfone ketone) hollow fiber membrane for gas separation

Poly(phthalazinone ether sulfone ketone) (PPESK) asymmetric hollow fiber membranes for gas separation were prepared by dry/wet phase inversion technique. The effects of various preparation conditions such as solvent, nonsolvent-additives(NSA), PPESK concentration, and air gap on the membrane performance were studied. The heat resistance of the PPESK hollow fiber membrane was also examined. The hollow fiber membrane prepared from solvent with stronger solubility showed low gas permeation and high O₂/N₂ selectivity due to the denser skin layer. Hollow fiber membrane made from PPESK/DMAc/EtOH/THF system had thicker skin layer than that made from PPESK/DMAc/GBL system with the same ratio of near-to-cloud-point of NSA, which resulted in the higher O₂/N₂ selectivity. Along with the increase of NSA content, the gas permeation increased and the O₂/N₂ selectivity decreased. The O₂/N₂ selectivity of hollow fiber membranes made from PPESK/DMAc/GBL and PPESK/DMAc/EtOH/THF systems were 4.9 and 4.8 respectively, when the membrane forming systems contained appropriate content of NSA. The high polymer concentration resulted in low gas permeation and high O₂/N₂ selectivity. When the air gap was excessively long, the membrane performance dropped because of the damage to the dense skin layer. There was no significant drop on the membrane performance when the operation temperature was elevated to 90°C. The average O₂/N₂ selectivity was higher than 3.0 at 70°C during a long period of 55 days' test time. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation and performances of poly(phthalazinone ether sulfone ketone) hollow fiber membranes with excellent thermotolerance

The cloud points of PPESK/NMP/H₂O ternary system at different temperatures were measured by titrimetric method. The binodal lines in the ternary phase diagram of the poly(phthalazinone ether sulfone ketone (PPESK) dope system was determined, on the basis of the cloud point experimental data being linearly fitted with the semiempirical linear cloud point correlation. Furthermore, phase separation behavior during the phase inversion of PPESK membrane‐forming system was discussed in terms of the phase diagram. Then, dry–wet spinning technique was employed in manufacturing PPESK hollow fiber membranes by immersion precipitation method. The cross‐section morphologies of hollow fibers were observed by scanning electronic microscopy. Also, the effects of dope solution composition and spinning parameters, including the coagulant composition and the spinning temperature on the separation performances of fibers, were evaluated by permeability measurements. The thermotolerance of the PPESK hollow fiber membranes prepared in the work was examined for the permeation operation at different temperatures and pressure differences. The experimental results showed that pure water flux increases several fold along with the temperature increases from 20 to 80°C at different operation pressures, while the solute rejection only decreases slightly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 878–884, 2006     

Preparation and characterization of carbon membranes made from poly(phthalazinone ether sulfone ketone)

Carbon membranes were prepared from a novel polymeric precursor of poly(phthalazinone ether sulfone ketone) (PPESK), of which the changes of microstructure and chemical compositions during pyrolysis from 500 °C to 950 °C were monitored by thermal gravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. It has been found that the weight loss of the PPESK precursor up to 800 °C is about 43.0 wt%. After the heat treatment, the typical chemical structure of the PPESK precursor disappears, at the same time a graphite-like structure with more aromatic rings is formed. The interlayer spacing (i.e., d value) decreases from 0.471 nm to 0.365 nm as the pyrolysis temperature increases. The gas permeation performance of carbon membranes has been tested using pure single gases including H₂, CO₂, O₂ and N₂. For the carbon membrane obtained by carbonizing the PPESK precursor at 800 °C, the maximum ideal permselectivities for H₂/N₂, CO₂/N₂ and O₂/N₂ gas pairs could reach 278.5, 213.8 and 27.5, respectively.     

Copolymerization and blending of poly(phthalazinone ether ketone)s to improve their melt processability

The melt processability of phthalazinone‐containing poly(aryl ether)s (PAEs) was improved through copolymerization and blending. Poly(phthalazinone ether ketone) (PPEK) copolymers containing phthalazinone and bisphenol‐A (BPA) moieties were synthesized through nucleophilic substitution polycondensation. The PPEK copolymers exhibited high glass transition temperatures, excellent thermooxidative properties, good mechanical properties and improved solubility, all of which can be tailored by changing the molar ratio of phthalazinone to bisphenol monomers. The rheological investigation indicated that the incorporation of the flexible BPA moiety into the main chain lowered the melt viscosity of the copolymers. To improve the melt processability further, polymer blends of a PPEK copolymer/polycarbonate (PC) were prepared. The results suggested that blending is an effective approach for improving the melt processability of phthalazinone‐containing PAEs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2575–2580, 2007     

Comparison of the water uptake and swelling between sulfonated poly(phthalazinone ether ketone ketone)s and sulfonated poly(arylene ether ketone ketone)s

Summary Sulfonated poly(phthalazinone ether ketone ketone)s (sPPEKK) and sulfonated poly(arylene ether ketone ketone sulfone)s (sPAEKK) were successfully synthesized by direct polycondensation. The water uptake and swelling of sPPEKK are much less compared with those of sPAEKK, especially in high temperature, which result from the powerful intermolecular hydrogen bonds of sPAEKK, confirmed by variable temperature IR spectra. The maximum operation temperature of proton exchange membranes made of sPPEKK is higher than 80 °C, improving the property of resistance to swelling.     

Interfacial shear strength in carbon fiber‐reinforced poly(phthalazinone ether ketone) composites

We studied interfacial shear strength (IFSS) in carbon fiber (CF)‐reinforced poly (phthalazinone ether ketone) (PPEK) composites system, with emphasis on the influence of forming temperature of composite and sizing agent on CFs. To obtain apparent IFSS of CF‐reinforced PPEK composites shaped at various forming temperatures ranged from 20 up to 370°C, microbond test was carried out at single‐fiber composites. Results of microbond test showed that apparent IFSS was directly proportional to the difference between the matrix solidification temperature (forming temperature) and the test temperature and approximately 80% of the apparent IFSS in CF/PPEK composite system was attributed to residual radial compressive stress at the fiber/matrix interface. By sizing CF with sizing agent, the wettability of the fiber by the matrix was improved and the final apparent IFSS was also improved. POLYM. COMPOS., 34:1921–1926, 2013. © 2013 Society of Plastics Engineers     

Preparation and characterization of functionalized carbon nanotubes/poly(phthalazinone ether sulfone ketone)s composites

Multiwalled carbon nanotubes (MWNT) were successfully functionalized with phthalazinone‐containing diamine (DHPZDA) groups by the amidation reaction. The morphologies and structures of the DHPZDA‐functionalized MWNT (MWNT‐DHPZDA) were characterized by scanning electron microscope, Fourier transform infrared, and Raman spectroscopy, revealing that the DHPZDA were covalently attached onto the surface of MWNT, and the weight gain due to the functionalization was determined by thermogravimetric analysis. The MWNT‐DHPZDA/poly(phthalazinone ether sulfone ketone)s (PPESK) composites with different filler content were prepared by the solution‐mixing method. MWNT‐DHPZDA can be uniformly dispersed in the matrix and the strong interfacial adhesion between two constituents was found, which resulted in obvious enhancements of the mechanical properties. For the composite with 1 wt% MWNT‐DHPZDA, the tensile strength and the Young's modulus are 102.1 and 1,974 MPa, about 1.65 and 1.72 times of the pure PPESK, respectively. Conductivity measurements indicate that a typical percolation transition behavior takes place for MWNT‐DHPZDA content in the range from 0.5 to 2 wt%. Additionally, introducing MWNT‐DHPZDA into PPESK is favorable to improvement of the thermal stability. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Direct synthesis of surface molecularly imprinted polymers based on vinyl–SiO2 nanospheres for recognition of bisphenol A

Molecularly imprinted polymers (MIP) with high performance in selectively recognizing bisphenol A (BPA) were prepared by using a novel and facile surface molecular‐imprinting technique. Vinyl‐functionalized, monodispersed silica spheres were synthesized by a one‐step emulsion reaction in aqueous solution. Then, BPA surface molecularly imprinted polymers (SMIP) were prepared by polymerization with 4‐vinylpyridine as the functional monomer and ethylene glycol dimethacrylate as the crosslinker. Maximal sorption capacity (Q_max) of the resulting SMIP was up to 600 μmol g^?1, while that of nonimprinted polymers was only 314.68 μmol g^?1. Kinetic binding study showed that sorption capacity reached 70% of Q_max in 20 min and sorption equilibrium at 80 min. SMIP had excellent accessibility and affinity toward BPA, for the selectivity coefficients of SMIP for BPA in respect to phenol, p‐tert‐butylphenol, and o‐phenylphenol were 3.39, 3.35, and 3.02, respectively. The reusage process verified the SMIP owning admirably stable adsorption capacity toward BPA for eight times. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Graphene‐based molecularly imprinted polymer for separation and pre‐concentration of trace polycyclic aromatic hydrocarbons in environmental water samples

A composite of reduced graphene oxide and pyrene‐imprinted polymer was synthesized and employed as a solid phase for extraction of five selected polycyclic aromatic hydrocarbons (PAHs) from water samples. Gas chromatography‐time of flight/mass spectrometry was employed in the analysis of the extracts. The composite was prepared by a free radical polymerization of methacrylic acid and 4‐vinylpyridine as monomers and ethylene glycol dimethacrylate as a crosslinker. The adsorption studies were carried out through batch binding studies. The binding capacity for the imprinted and non‐imprinted composite was 101.83 and 68.21 µg g^?1, respectively. The adsorption followed the pseudo 2nd order and well fitted the Langmuir isotherm. Mean recoveries ranging from 73% to 105.4% for both spiked deionized water and environmental water samples were obtained when the imprinted composites were employed in solid phase extraction of the PAHs. The composites could be re‐used for five times without a significant loss in recoveries. The proposed method was employed for the analysis of spiked environmental water samples and did not show significant changes in the recoveries showing there were no matrix interferences. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45300.     

杂萘联苯聚芳醚酮超滤膜的铸膜液配方研究

为了考察不同铸膜液配方对相转化法制备杂萘联苯聚芳醚酮(PPEK)非对称超滤膜的影响,按照固定1种组分质量分数,改变另外2种组分比例的方法,对铸膜液黏度、凝胶速度及膜结构和性能的变化规律进行了研究。结果表明,聚合物质量分数是决定黏度的主要因素,而铸膜液黏度和添加剂的亲水性对凝胶速度影响很大;铸膜液黏度和凝胶速度可以较好地解释膜结构和性能的变化规律。     

聚醚醚酮纤维的发展现状与应用

综述了国内外聚醚醚酮(PEEK)纤维的研究发展现状;分析了制约我国PEEK纤维发展的原因;介绍了PEEK树脂的流变性能、纺丝技术;阐述了PEEK纤维的结构、物理化学性能及应用领域;提出我国应加大PEEK原料及其纤维的研发,实现PEEK纤维国产化。     

Application of poly(phthalazinone ether sulfone ketone)s to gas membrane separation

A series of poly(phthalazinone ether sulfone ketone) (PPESK) copolymers containing different component ratios of bis(4‐fluorodiphenyl) ketone and bis(4‐chlorodiphenyl)sulfone with respect to a certain amount of 4‐(4‐hydroxyphenyl)‐2,3‐phthalazin‐1‐one were synthesized by polycondensation. Glass transition temperatures of these polymers were adjusted from 263°C to 305°C by changing the ratios of reactants. Gas permeability and selectivity of the dense membranes of the polymers for three kinds of gases (CO₂, O₂, and N₂) were determined at different temperatures. The result indicated that the membrane of PPESK (S/K = 1/1, mol ratio) had an excellent gas separation property. Permeability of the polymer membranes for CO₂, O₂, and N₂ was P = 4.121 barrier, P = 0.674 barrier, and P = 0.0891 barrier, respectively. Separation factors of α and α were 7.6 and 46, respectively. New material was made into a composite membrane with silicone rubber for blocking up leaks and defects on the surface of its nonsymmetrical membrane. As a result of the test, permeability of the composite membrane was J = 7.2 × 10⁻⁶ cm³ (STP) cm⁻² S⁻¹ cm⁻¹ Hg and J = 0.99 × 10⁻⁶ cm³ (STP) cm⁻² S⁻¹ cm⁻¹ Hg, whereas the α was still higher than 7. These showed that PPESKs had a bright prospect as the potential membrane material for high‐temperature gas separation. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2385–2390, 1999     

Properties and crystallization kinetics of poly(ether ether ketone)‐co‐poly(ether ether ketone ketone) block copolymers

A series of block copolymers composed of poly(ether ether ketone) (PEEK) and poly(ether ether ketone ketone) (PEEKK) components were prepared from their corresponding oligomers via a nucleophlilic aromatic substitution reaction. Various properties of the copolymers were investigated with differential scanning calorimetry (DSC) and a tensile testing machine. The results show that the copolymers exhibited no phase separation and that the relationship between the glass‐transition temperature (T_g) and the compositions of the copolymers approximately followed the formula T_g = T_g1X₁ + T_g2X₂, where T_g1 and T_g2 are the glass‐transition‐temperature values of PEEK and PEEKK, respectively, and X₁ and X₂ are the corresponding molar fractions of the PEEK and PEEKK segments in the copolymers, respectively. These copolymers showed good tensile properties. The crystallization kinetics of the copolymers were studied. The Avrami equation was used to describe the isothermal crystallization process. The nonisothermal crystallization was described by modified Avrami analysis by Jeziorny and by a combination of the Avrami and Ozawa equations. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1652–1658, 2005