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Blends of poly(ether imide) (PEI, Ultem 1000) and an aromatic poly(ether amide) were studied. Although homogeneous or heterogeneous blends can be obtained depending on the blend preparation method, the inherent miscibility of the mixture was finally established. The so-called enthalpy relaxation method was used to detect one or two glass transition temperatures in the blends in spite of the similarity of the pure component transitions. Fourier transform infrared analysis provided additional evidence of the specific interactions, which could be in the origin of the miscibility. A preliminary study of the influence of the homogeneity level in the transport properties of the blend films was also undertaken. Carbon dioxide at 1 bar was used as a penetrant. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 2141–2149, 1998 相似文献
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Kento Fujiura Mitsuru Naito Yukiko Tanaka Masaru Tanaka Yurie Nakanishi Hirotaka Ejima Lumi Negishi Tomoya Kujirai Hitoshi Kurumizaka Seiichi Ohta Kanjiro Miyata 《应用聚合物科学杂志》2024,141(11):e55044
Poly(ethylene glycol) (PEG) modification, also known as PEGylation, has been extensively used to improve the stability of nanoparticles for nanomedical applications. However, PEG exhibits antigenicity in some formulations, motivating researchers to explore alternative polymers. Herein, poly(vinyl ether) (PVE) derivatives are highlighted as promising alternatives to PEG because they form intermediate water molecules that suppress non-specific protein adsorption and platelet adhesion to the material surface. We prepared a water-soluble PVE derivative, poly(2-methoxyethyl vinyl ether) (PMOVE), and utilized it as a surface modifier for gold nanoparticles (AuNPs) as model nanoparticles. PMOVE with a thiol terminus was synthesized and confirmed to form an intermediate water molecule using differential scanning calorimetry. Similar to the synthesis of PEGylated AuNPs (PEG-AuNPs), PMOVE-modified AuNPs (PMOVE-AuNPs) were successfully fabricated with an appreciably high density of PMOVE palisades via a thiol-gold coordination reaction. Similar to PEG-AuNPs, PMOVE-AuNPs showed reduced serum protein adsorption and prolonged blood circulation. Additionally, no significant cytotoxicity was observed after incubation of a murine macrophage cell line, RAW264.7, with PMOVE-AuNPs. Our results indicate that the PMOVE modification increases the stealthiness of nanoparticles that is equivalent to that achieved by PEGylation. 相似文献
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含氟共聚芳醚酮的合成与性能研究 总被引:1,自引:0,他引:1
通过三步反应合成新的含氟双酚单体4-氟苯基对苯二酚,在该含氟双酚单体中加入不同比例的间苯二酚与4,4'-二氟二苯酮经亲核缩聚反应制备了一系列新型共聚芳醚酮.用傅立叶变换红外光谱仪、差示扫描量热仪、热失重分析仪及广角X射线衍射仪等对聚合物的结构和性能进行了表征和研究.结果表明,该共聚物为非晶态,具有优异的耐热性能,其玻璃化转变温度(Tg)在123~159℃、氮气中5%热失重温度在510℃以上;且具有良好的溶解性,室温下能溶解于N-甲基吡咯烷酮、N,N-二甲基乙酰胺、氯仿等有机溶剂. 相似文献
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《Journal of Industrial and Engineering Chemistry》2014,20(1):127-132
Nano-TiO2 was modified with 2-mercaptobenzimidazole via surfactant activation and used as an adsorbent for the removal of Ag(I) under optimum conditions. The adsorbent was characterized using powder X-ray diffraction and FT-IR spectroscopy. The equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherm models. Langmuir isotherm describes the adsorption data better than Freundlich isotherm and Temkin. Kinetic studies showed that the pseudo second order kinetic model fits the adsorption kinetic processes well. Maximum adsorption capacity for Ag(I) was 128.2 mg g−1 of nano-TiO2. The method was successfully applied to the removal of silver from radiology film processing wastewater samples. 相似文献
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以含二氮杂萘酮结构聚芳醚砜酮(PPESK)为基膜、均苯三甲酰氯为有机相单体、哌嗪与间苯二胺为水相单体通过界面聚合工艺制备了复合膜,研究了不同操作条件下复合膜对环丁砜水溶液的分离浓缩效果,考察了复合膜运行的稳定性与2次浓缩效果.结果表明,在50℃,1.8MPa下聚芳酰胺聚芳醚砜酮复合膜2次浓缩质量浓度10g·L~(-1)的环丁砜溶液,混合浓缩液环丁砜的质量浓度在28~36 g·L~(-1),透过液环丁砜的质量浓度为0.2 g·L~(-1),且13周静态及24 h连续分离操作性能稳定. 相似文献
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The thermal properties of blends of poly(ether ether ketone) (PEEK) and poly(ether imide) (PEI) prepared by screw extrusion were investigated by differential scanning calorimetry. From the thermal analysis of amorphous PEEK–PEI blends which were obtained by quenching in liquid nitrogen, a single glass transition temperature (Tg) and negative excess heat capacities of mixing were observed with the blend composition. These results indicate that there is a favorable interaction between the PEEK and PEI in the blends and that there is miscibility between the two components. From the Lu and Weiss equation and a modified equation from this work, the polymer–polymer interaction parameter (χ12) of the amorphous PEEK–PEI blends was calculated and found to range from −0.058 to −0.196 for the extruded blends with the compositions. The χ12 values calculated from this work appear to be lower than the χ12 values calculated from the Lu and Weiss equation. The χ12 values calculated from the Tg method both ways decreased with increase of the PEI weight fraction. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 733–739, 1999 相似文献
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Yao‐Chi Shu Fu‐Sheng Chuang Wen‐Chin Tsen Jing‐Dong Chow Chunli Gong Sheng Wen 《应用聚合物科学杂志》2008,107(5):2963-2969
This investigation examines characteristics of sulfonated polyether imides (SPEI) with various ion exchange capacity values (IEC) and completes previous work to enable its blends to be adopted as polyelectrolyte in direct methanol fuel cells (DMFC). Polyether imides (PEI) were sulfonated by using chlorosulfonic acid as the sulfonating agent and chloroform as the solvent. The structure of SPEI was observed by FTIR and 1H NMR. The sulfonate or sulfonic acid content of the polymers, expressed as a number per repeat unit of the polymer, was accurately determined by elemental analysis and conductometric titration. Physical properties such as solubility, intrinsic viscosities, thermal stability, and glass transition temperature (Tg) were studied for both PEI and SPEI. TGA‐FTIR verified that sulfonic groups, attached to the aromatic ring in the PEI backbone, are split at 230–350°C, but the main‐chain splitting temperature of SPEI is similar to that of pure polymer. The sulfonated samples exhibited good solubilities and increased glass transition temperatures (Tg values) as degree of sulfonation (DS) increased; two Tg values were detected when IEC was sufficiently high. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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Phenolphthalein poly(ether ether ketone) (PEK‐C) was found to be miscible with uncured tetraglycidyl 4,4′‐diaminodiphenylmethane (TGDDM), which is a type of tetrafunctional epoxy resin (ER), as shown by the existence of a single glass transition temperature (Tg) within the whole composition range. The miscibility between PEK‐C and TGDDM is considered to be due mainly to entropy contribution. Furthermore, blends of PEK‐C and TGDDM cured with 4,4′‐diaminodiphenylmethane (DDM) were studied using dynamic mechanical analysis (DMA), Fourier‐transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). DMA studies show that the DDM‐cured TGDDM/PEK‐C blends have only one Tg. SEM observation also confirmed that the blends were homogeneous. FTIR studies showed that the curing reaction is incomplete due to the high viscosity of PEK‐C. As the PEK‐C content increased, the tensile properties of the blends decreased slightly and the fracture toughness factor also showed a slight decreasing tendency, presumably due to the reduced crosslink density of the epoxy network. SEM observation of the fracture surfaces of fracture toughness test specimens showed the brittle nature of the fracture for the pure ER and its blends with PEK‐C. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 598–607, 2001 相似文献
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The crystallization and multiple melting behavior of poly(phenylene sulfide) (PPS) and its blends with amorphous thermoplastic bisphenol A polysulfone (PSF) and phenolphthalein poly(ether ketone) (PEK-C), crystalline thermoplastic poly(ether ether ketone) (PEEK), and thermosetting bismaleimide (BMI) resin were investigated by a differential scanning calorimeter (DSC). The addition of PSF and PEK-C was found to have no influence on the crystallization temperature (Tc) and heat of crystallization (ΔHc) of PPS. A significant increase in the value of Tc and the intensity of the Tc peak of PPS was observed and the crystallization of PPS can be accelerated in the presence of the PEEK component. An increase in the Tc of PPS can also be accelerated in the BMI/PPS blend, but was no more significant than that in the PEEK/PPS blend. The Tc of PPS in the PEEK/PPS blends is dependent on the maximum temperature of the heating scans and can be divided into three temperature regions. The addition of a second component has no influence on the formation of a multiple melting peak. The double melting peaks can also be observed when PPS and its blends are crystallized dynamically from the molten state. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 637–644, 1998 相似文献
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Jean‐Charles Sébileau Sébastien Lemonnier Elodie Barraud Marie‐France Vallat Adele Carradò Michel Nardin 《应用聚合物科学杂志》2017,134(23)
The present study deals with the consolidation of an ultra‐high performance polymer, the poly(ether ether ketone) (PEEK), for structural applications, using the powder metallurgy (PM) way, and more precisely the Spark Plasma Sintering (SPS) processing. The effects of SPS parameters such as temperature, pressure, and dwell time on density and mechanical properties of PEEK were investigated via a Design of Experiments (DoE). A temperature of 250 °C, a pressure of 40 MPa, and a dwell time of 20 min have been identified as the optimal SPS process parameters. In these conditions, a density of 1.31 g / cm3 was reached and homogeneous mechanical properties in the volume determined by means of compression tests were found with a compressive modulus of 2.75 GPa, a yield strength of 134 MPa, and a maximum compressive strain of 43%. These results are better than those of commercial products obtained by injection molding. The pressure appears to be a significant parameter on PEEK properties and plays positive or negative roles according to the responses of DoE studied. To our knowledge, it is one of the first studies based on the application of the PM techniques for PEEK consolidation showing the possibility to process below its melting point. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44911. 相似文献
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Poly(arylene ether sulfone) (PAES) multi-block copolymers bearing perfluoroalkylsulfonic acid moieties were prepared from hydrophilic and hydrophobic prepolymers. The latter were synthesized by reaction of N,N-diisopropylethylammonium 2,2-bis(p-hydroxyphenyl)pentafluoropropanesulfonate (HPPS) with bis-(4-fluorophenyl) sulfone (FPS), and biphenol (BP) with FPS, respectively. Prepolymers and multi-block copolymers were prepared at 180 °C in N,N-dimethylacetamide in the presence of K2CO3. The prepolymers were reacted overnight; the multi-block copolymers were reacted only 80 min to minimize transetherification. Prepolymers and multi-block copolymers were characterized using 1H and 13C NMR. 19F NMR provided molecular weight of hydrophilic prepolymers bearing aryl fluoride end groups. GPC was used to characterize the multi-block copolymers. Copolymer block lengths were determined by quantifying 13C NMR peak areas of quaternary carbon atoms adjacent to sulfur in FPS moieties. Hydrophilic and hydrophobic block lengths were in the range 9.4-23.4 and 4.4-11.8 repeating units, respectively. AFM showed phase separation for all block lengths. Conductivity at 80 °C and 100% relative humidity ranged from 6.2 to 34.3 mS/cm, with the best value obtained for hydrophilic/hydrophobic block lengths of 13.3/6.0. 相似文献
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A series of comb-type amphiphilic copolymers (PES-g-PEO) with a stiff poly(aryl ether sulfone) backbone and flexible PEO side chains was synthesized via a “grafting onto” technique. By controlling the monomer feed ratios, high molecular weight copolymers with a range of PEO side chain content were prepared and used to form tough and flexible membranes. The PES-g-PEO membranes displayed high thermal stability (Td > 230 °C) and good mechanical properties. The water contact angles of the PES-g-PEO membranes ranged from 60.5° to 66.7°, 20° lower than those of poly(aryl ether sulfone) membranes (82-86°), indicating that the PEO side chains improved the hydrophilicity of the membranes. Wide-angle X-ray diffraction results indicated that the PES-g-PEO membranes possessed an amorphous structure, that is, crystallization of the PEO side chains did not occur. The Li-ion conductivity reached 2.26 × 10−4 S/cm at room temperature, much higher than that of the pure PEO-based system (10−6 S/cm), due to the presence of the amorphous PEO side chains between the PES backbones, which provided an effective Li-ion transport pathway. 相似文献
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Blends of phenolphthalein poly(ether ether ketone) and a thermotropic liquid crystalline copolyester
Blends of phenolphthalein poly(ether ether ketone) (PEK-C) and a thermotropic liquid crystalline copolyester (LCP), poly[(1-phenylethyl-p-phenylene terephthalate)-co-(1-cumyl-p-phenylene terephthalate)], was prepared via melt mixing. The studies of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) indicate that the PEK-C/LCP blends display two glass transition temperatures which correspond to those of PEK-C- and LCP-rich phases, respectively. The PEK-C/LCP blends were judged to be partially miscible. Scanning electron microscopy (SEM) was employed to examine the morphology of the blends, and it was observed that all the PEK-C/LCP blends displayed a phase-separated structure. The interface between the PEK-C- and LCP-rich phases is poor. The Young's modulus of the PEK-C/LCP blends was found to increase with LCP content due to the high modulus of the LCP. However, the tensile strength and the elongation at break of the blends greatly decreases with increase of LCP content, owing to the poor interfacial adhesion. From the thermogravity analysis (TGA), it was observed that all the blends exhibited a two-step weight loss mechanism, and the thermal degradation onset temperature of the blends was lowered with the addition of LCP content. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1923–1931, 1998 相似文献
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聚合物光纤用P(3FEM)聚合工艺 总被引:2,自引:0,他引:2
介绍了氟单体甲基丙烯酸 2,2,2 三氟乙酯3FEM的性能及其提纯工艺,通过对引发剂的分析及其应用,选取过氧化羟基异丙苯和过氧化二苯甲酰BPO作引发剂,预聚时多要求单体转化率在10%以上,所测预聚液的粘度大于100mPa·s为佳。P(3FEM)的聚合是在一定的压力和温度下进行的,在聚合过程中,要及时消除反应热,消除爆聚现象,这样可获得透明氟树脂。经测试合成的P(3FEM)折射率为1.4167,θg为77.5℃,分解温度Td为380.7℃,氟树脂P(3FEM)可用作PMMA芯POF的皮材。 相似文献
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UASB-SBR工艺去除生活污水中磺胺二甲基嘧啶的试验研究 总被引:1,自引:0,他引:1
研究了UASB-SBR工艺对生活污水中磺胺二甲基嘧啶(SM2)的去除特性,并且在兼顾去除SM2和脱氮除磷的基础上,对工艺参数进行了优化。试验结果表明,UASB-SBR工艺对SM2有较好的去除效果,当温度为20℃,UASB反应器水力停留时间(HRT)为8 h,COD容积负荷为0.5~1.2 kg.m-.3d-1,进水pH在7.0~8.0时,COD、SM2平均去除率分别为70%、35%。在氮磷及SM2去除效果不佳的情况下,后续SBR反应器,当曝气时间为3 h,污泥龄(SRT)为20 d时,COD、TN、TP出水浓度均达到城镇污水处理厂污染物排放标准(GB 18918-2002)中的一级标准,SM2出水质量浓度为5~8μg·L-1,SM2总去除率为90%。厌氧段和好氧段对SM2的平均去除率分别为35%和55%,这说明SM2在好氧条件下更容易被降解。 相似文献