共查询到20条相似文献,搜索用时 15 毫秒
1.
通过共聚的方法在酚酞聚芳醚砜(PES-C)的主链上引入苯并咪唑酮和5,6-二甲基苯并咪唑酮结构,制备了一系列苯并咪唑酮和5,6-二甲基苯并咪唑酮结构含量不同的高玻璃化转变温度(T_g)聚芳醚砜共聚物。利用核磁共振谱(NMR)、傅里叶变换红外光谱仪(FTIR)、热重分析仪(TGA)等技术手段表征了三元共聚物的结构和性能。结果表明,聚芳醚砜共聚物为无定型结构。聚合物具有优异的热性能,并且均呈现出单一的T_g(T_g271℃);随着苯并咪唑酮和5,6-二甲基苯并咪唑酮的摩尔分数的增加,聚合物T_g呈现规律性升高,分别从270℃升高到340和344℃。两种共聚物均能够溶于极性非质子N,N-二甲基甲酰胺(DMF)、N,N-二甲基乙酰胺(DMAc)、二甲基亚砜(DMSO)、N-甲基吡咯烷酮(NMP)及氯仿(CHCl_3)等溶剂中。具有很好的溶解加工性和成膜性,可以进行溶液加工制备韧性的薄膜。 相似文献
2.
Sixun Zheng Jinyu Huang Yongcan Li Qipeng Guo 《Journal of Polymer Science.Polymer Physics》1997,35(9):1383-1392
The miscibility of blends of phenolphthalein poly(ether ether sulfone) (PES-C) and poly(ethylene oxide) (PEO) was established on the basis of the thermal analysis results. Differential scanning calorimetry (DSC) studies showed that the PES-C/PEO blends prepared by casting from N,N-dimethylformamide (DMF) possessed a single, composition-dependent glass transition temperature (Tg), and thus that PES-C and PEO are miscible in the amorphous state at all compositions at lower temperature. At higher temperature, the blends underwent phase separation, and the PES-C/PEO blend system was found to display a lower critical solution temperature (LCST) behavior. The phase separation process in the blends has also been investigated by using DSC. Annealed at high temperatures, the PES-C/PEO blends exhibited significant changes of thermal properties, such as the enthalpy of crystallization and fusion, temperatures of crystallization and melting, depending on blend composition when phase separation occurred. These changes reflect different characteristics of phase structure in the blends, and were taken as probes to determine phase boundary. From both the thermal analysis and optical microscopy, the phase diagram of the blend system was established. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 1383–1392, 1997 相似文献
3.
Random and block copolymers of poly (ether sulfone) (PES) and poly (ether ether sulfone) (PEES) were synthesized by the nucleophilic polycondensation of 4,4′‐dichlorodiphenyl sulfone (DCDPS) with 4,4′‐dihydroxydiphenyl sulfone (DHDPS) and hydroquinone (HQ). Chemical structures of these copolymers were characterized by 13C NMR. The monomer molar fraction, sequential distribution, and degree of randomness of the copolymers were determined through analyses of the resonances of quaternary carbons in the DCDPS unit. Experimental results show that the molar fractions of the comonomer determined by 13C NMR analyses are close to the charged values in the synthetic step. Moreover, these copolymers, which were prepared by different polymerization methods, revealed different number‐average sequential length and degree of randomness. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1624–1630, 2005 相似文献
4.
A series of cardo poly(aryl ether sulfone) copolymers bearing pendent sulfonic acid groups(SPES-X) have been prepared by a facile chemical graft method. The structure was confirmed by 1H-NMR spectra. The side-chain-type SPES-X membranes show significantly reduced swelling behavior and excellent mechanical properties as well as appropriate proton conductivity compared to the main-chain-type sulfonated polymers with similar ion exchange capacity(IEC) value. Moreover, they show methanol permeability in the range of 0.6 × 10-7-5.7 × 10-7 cm2/s which is lower than that of Nafion 117. All the results indicate that the SPES-X membranes are promising candidates for the direct methanol fuel cells. 相似文献
5.
YU Yun-wu XING Yan GUO Mei-mei LIU Bai-jun JIANG Zhen-hua Alan G. MacDiarmid Institute College of Chemistry Jilin University Changchun P. R. China 《高等学校化学研究》2011,(3):520-523
A novel type of crosslinkable poly(aryl ether sulfone)(PAES) bearing an allyl pendant(PES-OAllyl) was synthesized by a grafting reaction of hydrophenyl-containing PAES(PES-OH) and allyl bromide. PES-OH was prepared by a demethylation reaction of a methoxyphenylated PAES(PES-OCH3) in the presence of pyridine/hydrochlo- ride. The PES-OCH3 was synthesized by an aromatic nucleophilic substitution of bis(4-chlorophenyl)sulfone and (p-methoxy)phenylhydroquinone. Both DSC and solubility investigation were used to ... 相似文献
6.
Poly(arylene ether sulfone) copolymers derived from 9,9-bis(4-hydroxyphenyl)fluorene, bisphenol S and 4,4′-difluorodiphenylsulfone and poly(arylene ether ketone) copolymers derived from 4-phenoxybiphenyl, diphenyl ether and isophthaloyl chloride were prepared as precursor polymers for sulfonation reaction in which sulfonic groups are introduced quantitatively into specified positions. Sulfonation reaction for these two series of copolymers by concentrated sulfuric acid was successfully carried out to give sulfonated polymers with controlled positions and degree of sulfonation. Thermal stability, moisture absorption and proton conductivity for these two series of copolymers were measured and the results were compared to those of perfluorosulfonic acid polymers. 相似文献
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8.
Chi Wu 《Journal of Polymer Science.Polymer Physics》1994,32(5):803-810
Laser light scattering (LLS) including angular dependence of absolute integrated scattered intensity (static LLS) and of the spectral distribution (dynamic LLS) has been used successfully to characterize gelatin in formamide at room temperature. In static LLS, the use of formamide as a single solvent instead of an aqueous salt solution avoids the well-known problem of preferential sorption of salts in the domain of gelatin molecules. Therefore the true weight-average molecular weight Mw, the z-average radius of gyration, and the second virial coefficient have been determined. In dynamic LLS, precise measurements of the intensity-intensity time correlation function permit a Laplace inversion to obtain an estimate of the normalized characteristic linewidth distribution which could be reduced to a translational diffusion coefficient distribution, G(D). This report shows that the calibration between D and M can be established from Mw and G(D) by using only two broadly distributed gelatins instead of a set of narrowly distributed gelatin standards. After establishing a calibration between D and M, we were able to estimate the molecular weight distribution of gelatin from G(D). © 1994 John Wiley & Sons, Inc. 相似文献
9.
Francesco A. Bottino Giovanna Di Pasquale Nicoletta Leonardi Antonino Pollicino 《Journal of polymer science. Part A, Polymer chemistry》1996,34(7):1305-1310
High molecular-weight aromatic polyamides were obtained from 1,5- and 2,6-bis-(4′-carboxy-4-phenylenoxy-sulfonyl)naphthalene by direct polycondensation reaction in N-methyl-2-pyrrolidone with various aromatic diamines, using triphenyl phosphite and pyridine as condensing agents. The polymers were characterized by elemental analysis, thermogravimetric analysis, differential scanning calorimetry, and infrared analysis. The polyamides, obtained in quantitative yield, possessed inherent viscosities in the range 0.42–1.70 dL/g, glass transition temperatures between 245–310°C, and 10% weight loss temperatures in nitrogen and air above 435 and 424°C, respectively. Most of the polymers were soluble in aprotic solvents. The effect of the structure on properties, such as solubility, Tg, and thermal behavior, were also studied. © 1996 John Wiley & Sons, Inc. 相似文献
10.
Sean M. Mackinnon Timothy P. Bender Zhi Yuan Wang 《Journal of polymer science. Part A, Polymer chemistry》2000,38(1):9-17
The synthesis of a new A2X‐type difluoride monomer, N‐2‐pyridyl‐4′,4″‐bis‐(4‐fluorobenzenesulfonyl)‐o‐terphenyl‐3,6‐dimethyl‐4,5‐dicarboxylic imide ( 3 ), is described. The monomer 3 was incorporated into a series of copoly(aryl ether sulfone)s by polymerization of 4,4′‐isopropylidenediphenol and 4,4′‐difluorophenylsulfone. The incorporation of monomer 3 had an observable effect on both the glass‐transition temperature of poly(aryl ether sulfone)s and the tendency for macrocyclic oligomers to form during polymerization. Replacement of the pyridyl imide group via a transimidization reaction with propargyl amine proceeded quantitatively and without polymer degradation. The acetylene containing copoly(aryl ether sulfone) could be crosslinked by simple thermal treatment, resulting in an increase in the glass‐transition temperature and solvent resistance. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 9–17, 2000 相似文献
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Bhanu Nandan L. D. Kandpal G. N. Mathur 《Journal of Polymer Science.Polymer Physics》2004,42(8):1548-1563
Dynamic rheological measurements were carried out on blends of poly(ether ether ketone) (PEEK)/poly(aryl ether sulfone) (PES) in the melt state in the oscillatory shear mode. The data were analyzed for the fundamental rheological behavior to yield insight into the microstructure of PEEK/PES blends. A variation of complex viscosity with composition exhibited positive–negative deviations from the log‐additivity rule and was typical for a continuous‐discrete type of morphology with weak interaction among droplets. The point of transition showed that phase inversion takes place at composition with a 0.6 weight fraction of PEEK, which agreed with the actual morphology of these blends observed by scanning electron microscopy. Activation energy for flow, for blend compositions followed additive behavior, which indicated that PEEK/PES blends may have had some compatibility in the melt. Variation of the elastic modulus (G′) with composition showed a trend similar to that observed for complex viscosity. A three‐zone model used for understanding the dynamic moduli behavior of polymers demonstrated that PEEK follows plateau‐zone behavior, whereas PES exhibits only terminal‐zone behavior in the frequency range studied. The blends of these two polymers showed an intermediate behavior, and the crossover frequency shifted to the low‐frequency region as the PEEK content in PES increased. This revealed the shift of terminal‐zone behavior to low frequency with an increased PEEK percentage in the blend. Variation of relaxation time with composition suggested that slow relaxation of PEEK retards the relaxation process of PES as the PEEK concentration in the blend is increased because of the partial miscibility of the blend, which affects the constraint release process of pure components in the blend. A temperature‐independent correlation observed in the log–log plots of G′ versus loss modulus (G″) for different blend systems fulfilled the necessary condition for their rheological simplicity. Further, the composition‐dependent correlations of PEEK/PES blends observed in a log–log plot of G′ versus G″ showed that the blends are either partially miscible or immiscible and form a discrete‐continuous phase morphology. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1548–1563, 2004 相似文献
13.
The relationships among glass transition, crystallization, melting, and crystal morphology of poly(aryl ether ketone) (PAEK)/poly(other imide) (PEI) blends was studied by thermal, optical and small-angle x-ray scattering (SAXS) methods. Two types of PAEK were chosen for this work: poly(aryl ether ether ketone), PEEK, and poly(aryl ether ketone ketone), PEKK, which have distinctly different crystallization rates. Both PAEKs show complete miscibility with PEI in the amorphous phase. As PAEK crystallizes, the noncrystallizable PEI component is rejected from the crystalline region, resulting in a broad amorphous population, which was indicated by the broadening and the increase of Tg over that of the purely amorphous mixture. The presence of the PEI component significantly decreases the bulk crystallization and crystal growth rate of PAEK, but the equilibrium melting temperature and crystal surface free energies are not affected. The morphology of the PEI segregation was investigated by SAXS measurements. The results indicated that the inter(lamellar-bundle) PEI trapping morphology was dominant in the PEEK/PEI blends under rapid crystallization conditions, whereas the interspherulitic morphology was dominant in the slow crystallizing PEKK/PEI blends. These morphologies were qualitatively explained by the expression δ=D/G, where G was the crystal growth rate and D was the mutual diffusion coefficient. © 1993 John Wiley & Sons, Inc. 相似文献
14.
Thermal behavior and phase behavior in blends of liquid crystalline poly(aryl ether ketone) with lateral methoxy groups (M-PAEK) and poly(aryl ether ether ketone) containing thioether units (S-PEEK) have been investigated by differential scanning calorimetry (DSC) and polarized light microscopy (PLM) techniques. The results indicate that the composition of the blends has great effect on the phase behavior and morphology. Thin films of pure M-PAEK and S-PEEK crystallized from the melts exhibit typical mosaic and spherulitic structures, respectively. For the blends with higher M-PAEK contents (> 50%), an unusual ring-banded spherulite with structural discontinuity is formed. The bright core and rings of the ring-banded spherulites under PLM are composed of M-PAEK phase, while the dark rings consist mainly of S-PEEK phase. For the 50:50 M-PAEK/S-PEEK blend, the ring-banded spherulites and S-PEEK spherulites coexist, which implies that a partial phase separation between the two components takes place in the melting state. In S-PEEK-rich blends, a volume-filled spherulite is produced. In addition, the effect of isothermal crystallization temperature on the phase behavior, especially the ring-banded spherulite formation in the blends, is discussed. 相似文献
15.
Li Hong Xiao Cheng Liu Xi Gao Jian 《中国化学快报》2008,19(2):227-229
A novel series of poly(aryl ether sulfone ketone)s (PPESKs) containing phthalazinone and biphenyl moieties were prepared by two-step nucleophilic polycondensation reaction. The ^-Mw values of these copolymers were between 38,330 and 67,900. The glass transition temperatures (Tg) and 5% decomposition temperatures were ranged in 253-269 ℃ and 488-500 ℃, respectively, The structures of these copolymers were confirmed by FT-IR and ^1H NMR. Moreover, all the resultant copolymers were amorphous determined by wide angle X-ray diffraction (WAXD). 相似文献
16.
In this communication, a simple method for the preparation of environmentally responsive membrane, in situ redox-graft pore filling polymerization, was reported. Phenolphthalein poly(ether sulfone) dissolved in dimethyl sulfoxide was used to prepare porous membranes by means of classical phase inversion method. After that, methylacrylic acid was grafted successfully onto the membranes using the method reported here. Then, surface chemical changes and membrane morphology changes before and after graft polymerization were investigated by the ATR–FTIR and FESEM, respectively, to ascertain the formation and location of graft. Besides, the graft yield was also determined gravimetrically under different monomer concentrations. At last, in the hydraulic permeability experiments and diffusional permeability experiments using VB12 and KCl as solutes, the grafted membranes prepared using the reported method exhibited marked, rapid and reversible pH-response. 相似文献
17.
The physical aging process of 4,4′-diaminodiphenylsulfone (DDS) cured diglycidyl ether bisphenol-A (DGEBA) blended with poly(ether sulfone) (PES) was studied by differential scanning calorimetry (DSC) at four aging temperatures between Tg-50°C and Tg-10°C. At aging temperatures between Tg-50 and Tg-30°C, the experimental results of epoxy resin blended with 20 wt% of PES showed two enthalpy relaxation processes. One relaxation process was due to the physical aging of PES, the other relaxation process was due to the physical aging of epoxy resin. The distribution of enthalpy relaxation process due to physical aging of epoxy resin in the blend was broader and the characteristic relaxation time shorter than those of pure epoxy resin at the above aging temperatures (between Tg-50 and Tg-30°C). At an aging temperature between Tg-30 and Tg-10°C, only one enthalpy relaxation process was found for the epoxy resin blended with PES, the relaxation process was similar to that of pure epoxy resin. The enthalpy relaxation process due to the physical aging of PES in the epoxy matrix was similar to that of pure PES at aging temperatures between Tg-50 and Tg-10°C. © 1997 John Wiley & Sons, Inc. 相似文献
18.
Binary melt‐blended mixtures of two aryl ether ketone polymers (i.e., a new poly(aryl ether ketone) (code name PK99) and poly(ether ether ketone) (PEEK), have been studied. Polymer miscibility in glassy amorphous (or melt) domains has been demonstrated for the binary blend comprising of two aryl‐ether‐ketone‐type semicrystalline polymers. Composition‐dependent, single Tg was observed within full composition range in the PK99/PEEK blends, and the narrow Tg breadth also suggests that the scale of mixing was fine and uniform. To better resolve any possible overlapping Tg's, physical aging was imposed on a comparison set of blend samples for the purpose of improving detectability of overlapped multiple transitions if existing. The result still showed one single Tg. The relative sharp Tg and lack of cloud point transition suggest that the scale of molecular intermixing is good. Phase homogeneity was further confirmed using optical and scanning electron microscopy. The X‐ray diffractograms suggest that isomorphism does not exist in the PK99/PEEK blends and that the crystal forms of the respective polymers remain distinct and unchanged by the miscibility in the amorphous region. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1485–1494, 1999 相似文献
19.
Sheng-Huei Hsiao Perng-Chih Huang 《Journal of polymer science. Part A, Polymer chemistry》1998,36(10):1649-1656
Two sulfonyl group-containing bis(ether anhydride)s, 4,4′-[sulfonylbis(1,4-phenylene)dioxy]diphthalic anhydride ( IV ) and 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenylene)dioxy]diphthalic anhydride (Me- IV ), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of the bisphenolate ions of 4,4′-sulfonyldiphenol and 4,4′-sulfonylbis(2,6-dimethylphenol) with 4-nitrophthalonitrile in N,N-dimethylformamide (DMF). High-molar-mass aromatic poly(ether sulfone imide)s were synthesized via a conventional two-stage procedure from the bis(ether anhydride)s and various aromatic diamines. The inherent viscosities of the intermediate poly(ether sulfone amic acid)s were in the ranges of 0.30–0.47 dL/g for those from IV and 0.64–1.34 dL/g for those from Me- IV. After thermal imidization, the resulting two series of poly(ether sulfone imide)s had inherent viscosities of 0.25–0.49 and 0.39–1.19 dL/g, respectively. Most of the polyimides showed distinct glass transitions on their differential scanning calorimetry (DSC) curves, and their glass transition temperatures (Tg) were recorded between 223–253 and 252–288°C, respectively. The results of thermogravimetry (TG) revealed that all the poly(ether sulfone imide)s showed no significant weight loss before 400°C. The methyl-substituted polymers showed higher Tg's but lower initial decomposition temperatures and less solubility compared to the corresponding unsubstituted polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1649–1656, 1998 相似文献
20.
为得到具有高电导率和稳定性的阴离子交换膜,采用两步聚合法合成了含芴的序列式聚芳醚砜,经付克氯甲基化、季铵化及碱化制备了季铵化聚芳醚砜,并以脂肪族二胺(N,N,N′,N′-四甲基丙二胺(TMPDA)及N,N,N′,N′-四甲基己二胺(TMHDA))为交联剂,通过直接交联及后交联法分别制备了2类序列交联型阴离子交换膜.制得的膜材料离子交换容量为1.59~2.12 mmol/g,柔韧结实.与具有相似离子交换容量的非交联膜相比,交联膜的抗溶剂性能、尺寸稳定性、离子电导率等性能均得到了提高.交联膜在高温水中的水解稳定性、强碱性条件下的化学稳定性显著增强.探讨了直接浇铸交联处理及成膜后交联处理2种交联方式对膜性能的影响,结果表明,后交联处理可以有效避免浇膜过程凝胶的形成,而且膜的稳定性相对于未交联膜有大幅度提高.尤其以TMHDA为交联剂的后交联膜的各项性能均优于相应非交联膜,IEC为2.17 mmol/g的PCL-M(H)膜,在30°C时吸水率为99%,膜径向尺寸变化率为15%,电导率为23.8 mS/cm,90°C时电导率达到82 mS/cm,经过4 mol/L的NaOH溶液室温处理240 h后,离子电导率损失为7.6%,100°C水处理24 h后重量损失为5.1%,表现出较好的稳定性. 相似文献