共查询到20条相似文献，搜索用时 31 毫秒
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聚异丁烯（PIB）具有优异的耐介质性能,作为化工添加剂被广泛应用于各种化工材料,将聚异丁烯应用于胶黏剂及密封胶可有效稳定黏度,降低黏温性;同时促进粘接,提高耐介质性能,增加低温下的柔韧性。研究了4种不同的聚异丁烯在单组分室温硫化硅橡胶（RTV-1）中的应用。通过在RTV-1中添加不同相对分子质量的PIB,重点考查PIB对于RTV-1拉伸强度、伸长率及耐介质老化性能的影响。结果发现,添加PIB所制得的RTV-1拉伸强度可达2MPa,伸长率370％左右,同时耐机油、耐水性、耐热氧老化性能优异。 相似文献
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聚异丁烯胺汽油清净剂的合成过程研究 总被引：5，自引：0，他引：5
研究了用溴化加成法合成新一代的汽油清净剂聚丁烯胺(PIBA)。将高活性聚异丁烯与HBr气体在过氧化物存在下进行自由基反马氏加成反应生成溴化聚异丁烯,然后再与氨进行亲核取代反应生成聚异丁烯胺。实验研究了溶剂,反应时间,反应温度以及引发剂的加入量对反应过程的影响,基本确定了最佳反应条件。 相似文献
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从原胶、炭黑、增塑剂及硫化体系的类型对胶料在乙醇汽油中的溶胀性能的影响进行了研究。结果表明,选择橡塑合金NV7050作为原胶,加入N550与N774炭黑各40份,选择增塑剂TP-95和过氧化物硫化体系的胶料在乙醇汽油E10中体积及质量变化率较小,呈现良好的力学稳定性,耐乙醇汽油溶胀性能较好。 相似文献
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橡胶材料对甲醇汽油的抗溶胀性研究 总被引：1，自引：0，他引：1
郇延建 《化学工业与工程技术》2009,30(3):14-16
甲醇作为一种性能优良的替代燃料,其对橡胶材料具有很大的溶胀危害,这在很大程度上制约了甲醇汽油的发展。选取汽车上常用的几种橡胶材料分别进行汽油和甲醇汽油的溶胀试验,分析出可用于甲醇汽油上的抗溶胀性较好的橡胶材料。 相似文献
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PVC改性NBR在甲醇汽油混合燃料中溶胀程度的研究 总被引：5，自引：2，他引：3
研究了ＰＶＣ改性ＮＢＲ在高比例和低比例甲醇的甲醇汽油混合燃料中的溶胀程度。考虑到胶料的物理机械性能与溶胀性能,在前者中应选用ＰＶＣ改性的ＮＢＲ－２６或ＮＢＲ－４０,在后者中应选用ＰＶＣ改性的ＮＢＲ－４０。ＰＶＣ用量以２０－３０份为宜。 相似文献
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阐述了国内甲醇汽油对车用非金属材料溶胀性能的相关研究情况。依据近年来甲醇汽油研究领域公开发表的著作、期刊文章、学位论文、发明专利等文献,从溶胀作用机理研究、实验研究、抑制剂研究三个方面进行归类总结,并探讨了甲醇汽油及溶胀性研究中存在的问题。文献分析结果表明:对溶胀作用机理的研究不够充分,大多停留在猜测和佐证阶段,没有直观的机理分析;车用非金属材料在甲醇汽油中的浸泡实验研究较为充分,结论也趋于一致;有关溶胀抑制剂的参考文献较少,已公布的各种抑制剂配方差别较大,缺乏统一的评判标准;甲醇汽油溶胀作用研究方面仍存在许多不足,需要逐步完善和解决。清楚了解甲醇汽油溶胀性研究的已有成果和欠缺,能够为相关科研工作者开展后续深入研究提供参考和方向。 相似文献
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We fabricated novel composite membranes composed of a polymer of intrinsic microporosity (PIM-1) and carbon black (CB) nanoparticles functionalized with the silane coupling agent aminopropyl triethoxysilane to recover butanol from aqueous solutions by pervaporation (PV). Scanning electron microscopy showed that the composite membranes were dense and defect free and had good adhesion with substrates. Compared with the those of pristine PIM-1 membranes, the water contact angles of the composite membranes increased from around 86° to more than 90°; this confirmed the improvement of the hydrophobicity. The swelling degree of the 6 wt % CB-filled PIM-1 membranes dropped 23%; this indicated an increase in the swelling resistance. Furthermore, the PV results show experimentally that the incorporation of the functionalized CBs into the PIM-1 matrix considerably improved both the permeability and selectivity to butanol. At a 4 wt % CB content, the optimum separation performance, with a separation factor of 19.7 and a permeation flux of 1116 g m−2 h−1, was achieved in an aqueous solution containing 5 wt % butanol at 30°C. It was noteworthy that the as-fabricated membranes exhibited a good separation stability. This is a step forward in terms of continuous butanol production with hybrid membranes in fermentation processes. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46912. 相似文献
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In this study, retention experiments were performed to characterize the variable sieving properties of a poly(dimethylsiloxane) (PDMS) membrane in relation with operating parameters. The swelling, transmembrane pressure, and temperature are all known to impact the physicochemical properties and morphology of PDMS polymer and were therefore varied for the purposes of our retention experiments which assessed them with the homologous series of polyethylene glycols (PEGs; 200–1500 g mol?1). The objectives were twofold—first, to evaluate the capacity to induce a targeted molecular weight cutoff (MWCO) by selecting appropriate filtration conditions and second to better understand the mechanisms involved during solvent‐resistant nanofiltration with PDMS. The selected solvents or solvent/solvent mixtures used throughout this study were found to induce swelling ratios of 1.16 (ethanol/ethyl acetate: 25/75), 1.26 (ethyl acetate), 1.33 (ethyl acetate/toluene: 50/50), and 1.41 (toluene), respectively. Linear correlations were obtained between the MWCO and the swelling ratio induced by each solvent and between the MWCO and the transmembrane pressure. Pore size calculations using solvent flux and retention data confirmed the variable sieving properties of the PDMS membrane in relation to the solvent‐induced swelling and applied transmembrane pressure. In addition, the study of the solute‐transfer rate through several operating conditions showed that both diffusive and convective transports occurred for the PEG solutes and that their respective contributions appeared dependent on the variable pore size of the PDMS membrane. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41171. 相似文献
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As a core component of anion exchange membrane (AEM) fuel cells, it has practical significance to improve the performance of AEMs. However, it is difficult to obtain AEM with both good stability and high conductivity. In this study, a series of AEMs were prepared by chloromethylation, quaternization, and crosslinking reactions. The quaternization reaction was carried out first to ensure that there are abundant quaternary ammonium groups on AEM and enhance the conductivity of membrane. N,N,N′,N′-tetramethylethylenediamine was used as a crosslinker to improve membrane stability and mechanical property. A simple, mild, and cost-effective AEM synthetic route was developed. This strategy achieves a certain balance of electrochemical and physical properties. The effect of the crosslinking reactions on the property of membrane was evaluated. Crosslinked membranes have better dimensional stability (water uptake: 20.2% and swelling ratio: 2.1%), mechanical properties (55.84 MPa), and alkaline stability because crosslinked structures result in large steric hindrance. The mutually independent quaternization and crosslinking reaction do not affect the electrochemical performance of membranes; in the crosslinking reaction stage, crosslinker also reacted as quaternization agent and increased the number of reactive groups in AEM. Thus, the resulting crosslinked AEM exhibits higher ion exchange capacity and ionic conductivities (46.4 mS cm−1). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48169. 相似文献
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Stefan Scheler 《应用聚合物科学杂志》2007,105(5):3121-3131
A trivariate interpolation technique, the modified Shepard's method, was applied for the first time to explain and predict various properties of macroporous polymers from the Hansen solubility parameters of the porogens employed for polymerization. Highly crosslinked polymers and copolymers were prepared from ethylene glycol dimethacrylate and methacrylic acid by free‐radical polymerization with 30 different porogenic solvents. Instead of the spherical model used by Hansen, detailed three‐dimensional maps were computed to represent the measured properties in a δd–δp–δh diagram (where δd, δp, and δh are the Hansen solubility parameters according to the three types of bonding forces: dispersion, polar, and hydrogen‐bonding, respectively). This method was able to detect unapparent correlations between the different polymer properties, thus providing a better understanding of the pore‐formation process. An important finding was the crucial role of the initiator solubility and its partitioning between the solution and the polymer surface, which proved to be key factors for the explanation of many contradictory solvent effects. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
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SPEEK/phosphate salts membranes were prepared and utilized for CO2/CH4 separation. SPEEK with abundant –SO3H groups and EO groups on polymer chains would be beneficial for CO2 transport. The doped phosphate salts (NaH2PO4, Na2HPO4 and Na3PO4) with different acid‐base properties increased the water content in the membrane, and water was expected to increase both the solubility and diffusivity of CO2 in the membrane. All membranes were characterized by FTIR, TGA, and XRD. The CO2 permeability and CO2/CH4 selectivity of SPEEK/Na3PO4 membranes were higher than that of SPEEK/NaH2PO4 and SPEEK/Na2HPO4 membranes. Compared to the pure SPEEK membrane, the CO2 permeability and CO2/CH4 selectivity of SPEEK/Na3PO4?10 membrane were increased by 144% and 65%, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43399. 相似文献
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Christopher J. Orme John R. Klaehn Mason K. Harrup Robert P. Lash Frederick F. Stewart 《应用聚合物科学杂志》2005,97(3):939-945
Two linear phosphazene polymers were synthesized with differing amounts of hydrophilic 2‐(2‐methoxyethoxy)ethanol (MEE) and hydrophobic 4‐methoxyphenol (MEOP) substituted on the backbone. These high polymers were cast into membranes and their permeability to water, methanol, ethanol, and 2‐propanol was evaluated as a function of temperature. An additional polymer with a low content of MEE was studied for water permeation and was characterized by trace flux. At higher levels of MEE on the backbone, fluxes of all solvents increased. Solubility also was found to increase with increasing MEE content for all solvents except water. Unexpectedly, water was found to be less soluble in the higher MEE polymer, although higher membrane fluxes were observed. Diffusion coefficients showed the following trend: methanol ? 2‐propanol > ethanol ? water. Finally, the affinity of solvents and polymers was discussed in terms of Hansen solubility parameters. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 939–945, 2005 相似文献
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Novel facilitated‐transport mixed‐matrix membrane (MMM) were prepared through the incorporation of polydopamine (PDA) microspheres into a poly(amide‐b‐ethylene oxide) (Pebax MH 1657) matrix to separate CO2–CH4 gas mixtures. The Pebax–PDA microsphere MMMs were characterized by Fourier transform infrared spectroscopy, scanning electron microcopy, X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. The PDA microspheres acted as an adhesive filler and generated strong interfacial interactions with the polymer matrix; this generated a polymer chain rigidification region near the polymer–filler interface. Polymer chain rigidification usually results in a larger resistance to the transport of gas with a larger molecular diameter and a higher CO2–CH4 selectivity. In addition, the surface of PDA microspheres contained larger numbers of amine, imine, and catechol groups; these were beneficial to the improvement of the CO2 separation performance. Compared with the pristine Pebax membrane, the MMM with a 5 wt % PDA microsphere loading displayed a higher gas permeability and selectivity; their CO2 permeability and CO2–CH4 selectivity were increased by 61 and 60%, respectively, and surpassed the 2008 Robeson upper bound line. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44564. 相似文献
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Quaternary ammonium functionalized poly(arylene ether) (QPAE‐Br) membranes based on 2,2′,6,6′‐tetramethyl biphenol for diffusion dialysis (DD) were designed and successfully fabricated via nucleophilic substitution polycondensation, bromination, film casting, and quaternization. The structures, thicknesses, ion‐exchange capacities (IECs), water uptakes, swelling ratios, ion conductivities, and mechanical properties of QPAE‐Br were used to characterize the membranes. The influence of the membrane structures on the DD performances was investigated by DD tests of simulated industrial pickling wastewater (1 mol/L HCl, 0.1 mol/L FeCl2). The DD results show QPAE‐a (IEC = 1.51 mmol/g) as the best DD candidate. Predialysis treatments further improved the DD performances of QPAE‐Br. QPAE‐a exhibited an excellent proton diffusion coefficient ( ) of 0.033 m/h and a high separation factor (S) of 95.45 after the predialysis treatment at room temperature; these values were much higher than those of the commercial DF‐120B membrane (0.004 m/h for and 24.3 for S at 25 °C) and other reported DD membranes. QPAE‐a has great potential for acid recovery via DD. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45333. 相似文献
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A novel thin film composite‐type forward osmosis (FO) membrane with inhibited concentration polarization phenomenon and expectant separation performance was prepared by continuous interfacial polymerization method. The nylon‐6,6 microfiltration membrane with the average pore size of 5 μm and the self‐wetting property was for the first time used as the supporting layer of the FO membranes, which decreased the mass transfer resistance in the porous supporting layer. The skin layer was prepared via the continuous interfacial polymerization of polyamide as a relatively dense layer, with the reverse salt flux of less than 1 g/m?2 h?1. The mass transfer resistance and the reverse salt flux of the prepared FO membranes were remarkably reduced due to the functional design of the double‐layer structure, which effectively enhanced the separation selectivity and restrain the concentration polarization of the FO membranes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45133. 相似文献
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To convert highly brittle into flexible membrane, the polystyrene sulfonic acid-co-maleic acid crosslinked sodium alginate (PSSAMA/NaAlg) membrane was modified by incorporating the different weight% of dibutyl phthalate (DBP) as a plasticizer. The effect of DBP content on the physico-chemical properties of the membranes was thoroughly examined. The membranes exhibited lower glass transition temperatures with increasing the plasticizer content in the matrix of PSSAMA/NaAlg. The separation performance of the membranes for water/isopropanol and water/1,4-dioxane was studied at different temperatures. Among the modified membranes, the membrane containing 6 wt% of DBP exhibited the highest separation factors of 24,129 with a flux of 13.57 × 10−2 kg/m2 hr and 23,353 with a flux of 12.99 × 10−2 kg/m2 hr for water/isopropanol and water/1,4-dioxane at 30°C, respectively. From the temperature-dependent diffusion and permeation values, the Arrhenius activation parameters were estimated. The estimated activation energy values for permeation of water (Epw) and isopropanol (EpIPA) were, respectively, ranged between 12.09 and 8.79, and 42.52 and 32.79 kJ/mol. A negative heat of sorption (ΔHs) values was obtained for all the membranes, suggesting that Langmuir's mode of sorption was predominant. Based on the results, it is concluded that the modified membranes demonstrated excellent pervaporation performance for the separation of water/isopropanol and water/1,4-dioxane. 相似文献