聚异丁烯改性硅橡胶的耐介质性能研究

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。     

PVC改性NVE在甲醇汽油混合燃料中溶胀程度的研究

研究了ＰＶＣ改性ＮＢＲ在高比例和低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，在前中应选用ＰＶＣ改性的ＮＢＲ－２６或ＮＢＲ－４０，在后中应选用ＰＶＣ改性的ＮＢＲ－４０，ＰＶＣ用量以２０－３０份为宜。     

甲醇汽油的腐蚀性和溶胀性研究

考察了不同配方甲醇汽油的腐蚀性与溶胀性,并对其存在的问题提出了对策。     

聚异丁烯胺汽油清净剂的合成过程研究

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。     

耐乙醇汽油橡胶材料溶胀性能的研究

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。     

橡胶材料对甲醇汽油的抗溶胀性研究

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。     

橡胶材料对甲醇汽油的抗溶胀性研究

甲醇作为一种性能优良的替代燃料,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。本文选取汽车上常用的几种橡胶材料分别进行汽油和甲醇的溶胀性试验,最后得出可用于甲醇汽油上的抗溶胀性较好的橡胶材料。     

PVC改性NBR在甲醇汽油混合燃料中溶胀程度的研究

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。     

改性酚醛胺环氧树脂体系耐蒸馏水的研究

通过宏观试验和AFM微观分析证明,改性酚醛胺固化环氧树脂体系的耐蒸馏水性能,优于低分子聚酰胺固化的环氧树脂体系。     

车用甲醇汽油的溶胀性研究

采用浸泡法,对汽车上常用的几种橡胶材料分别进行汽油和甲醇的溶胀性试验,最后找出可用于甲醇汽油中的抗溶胀性较好的橡胶材料.试验结果表明:甲醇对某些橡胶材料具有很大的溶胀危害.必须选用抗溶胀性较好的橡胶材料制作甲醇汽油的燃油供给系统的配件.     

Chemical modification and structural rearrangements of polyketone‐based polymer membrane

Alternating polyketones constitute a very interesting class of polymers, which can be modified for the preparation of functional polymers. The chemical modification of polyketone using 1,2‐diaminopropane was used to prepare a conductive membrane. This paper is focused on the synthesis and structural rearrangements of polyamine for preparing anion‐exchange membranes by the solvent casting technique. According to the Paal‐Knorr mechanism, 1,4‐dicarbonyl of polyketone reacts with 1,2‐diaminopropane to form a pyrrole ring along the polyketone backbone. In addition, the so‐modified polyamines can undergo structural rearrangements to form N‐substituted pyrrole crosslinked with dihydropyridine units. The conversion degree and the N content are quite low. The pathway reactions have been proposed on the basis of ¹H‐NMR, ultraviolet–visible, and Fourier transform infrared results. Scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction techniques were used to study the morphological, thermal, and structural characteristics of the modified polyketone, as well as the correspondoing membrane. The experimental results indicated that the membrane is a potential candidate for energy conversion technology. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45485.     

Crosslinked anion exchange membrane with improved membrane stability and conductivity for alkaline fuel cells

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.     

A novel conductive membrane with RGO/PVDF coated on carbon fiber cloth for fouling reduction with electric field in separating polyacrylamide

Directly applying an electric field on conductive membrane can effectively mitigate membrane fouling. Thus, a conductive reduced graphene oxide/polyvinylidene fluoride (RGO/PVDF) membrane was prepared by casting PVDF and graphene oxide (GO) solution over a selected carbon fiber cloth, then phase inversion and final heat treatment in hydroiodic acid (HI) solution. This method realized uniform and stable presence of RGO in PVDF membrane. Scanning electron microscopy (SEM) images showed addition of GO reduced the pore size of the composite membranes. The thermal HI treatment partially reduced graphene oxide to RGO, and made the membrane more conductive but less hydrophilic [as characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and contact angle (CA)]. From thermogravimetric analysis (TGA), it showed that the addition of GO and RGO improved the thermal stability of the membranes, when temperature was lower than 400 °C. The HI treatment increased the pore size and water flux of the RGO/PVDF membrane (being 71.6% higher than the GO/PVDF membrane). The RGO/PVDF membrane was used in separating polyacrylamide (PAM), a macromolecule pollutant in oil field waste water; when applying a 0.6 V/cm external electric field, its membrane fouling and flux decline was effectively slowed down, as shown in the fitting curves slopes using the classical cake filtration model (t/V–V). Being uniform and stable, the RGO/PVDF membrane had great potential for practical applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43597.     

Surface modification of polyamide TFC membranes via redox‐initiated graft polymerization of acrylic acid

In this work, the redox‐initiated graft polymerization of acrylic acid (AA) onto the surface of polyamide thin film composite membranes has been carried out to enhance membrane separation and antifouling properties. The membrane surface characteristics were determined through the attenuated total reflection Fourier transform infrared spectra, scanning electron microscopy, atomic force microscopy, and water contact angles. The membrane separation performance was evaluated through membrane flux and rejection of some organic compounds such as reactive red dye (RR261), humic acid, and bovine serum albumin in aqueous feed solutions. The experimental results indicated that the membrane surfaces became more hydrophilic and smoother after grafting of AA. The modified membranes have a better separation performance with a significant enhancement of flux at a great retention. The fouling resistance of the modified membranes is also clearly improved with the higher maintained flux ratio and the lower irreversible fouling factor compared to the unmodified one. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45110.     

低压甲醇分离技术探讨

论述低压甲醇分离器分离效果对生产的影响,分析目前各种分离技术特点,总结出切实有效的甲醇分离技术。     

Vacuum membrane distillation simulation of desalination using polypropylene hydrophobic microporous membrane

Numerical simulation is an effective method to get the optimal operating parameters in the chemical engineering process. In this work, the transport mechanism of vacuum membrane distillation (VMD) process was simulated and predicted by mathematical model, which was established based on the convective heat transfer coefficient, and 0.5M aqueous NaCl solution was concentrated with isotactic polypropylene (iPP) hydrophobic microporous membrane prepared via thermally induced phase separation (TIPS) in the VMD process. The as‐presented mathematical model simulated the effects of different operating parameters on the VMD performances for aqueous NaCl solution, such as feed temperature, feed flow rate, absolute pressure of membrane permeate side, temperature coefficient, membrane thickness, and porosity. A comparison between experimental data and simulated data was also considered to verify the proposed mathematical model. Additionally, the salt rejection of aqueous NaCl solution production water in VMD was higher than 99.9%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41632.     

Preparation and characterization of a novel positively charged nanofiltration membrane based on polysulfone

The goal of this study was to prepare positively charged nanofiltration (NF) membranes to remove cations from aqueous solutions. A composite NF membrane was fabricated by the modification of a polysulfone ultrafiltration support. The active top layer was formed by the interfacial crosslinking polymerization of poly(ethylene imine) (PEI) with p‐xylene dichloride (XDC). Then, it was quaternized by methyl iodide (MI) to form a perpetually positively charged layer. The chemical and morphological changes of the membrane surfaces were studied by Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy. To optimize the membrane operation, the PEI solution concentration, PEI coating time, XDC concentration, crosslinking time, and MI concentration were optimized. Consequently, high water flux (5.4 L m^?2 h^?1 bar^?1) and CaCl₂ rejection (94%) values were obtained for the composite membranes at 4 bars and 30°C. The rejections of the NF membrane for different salt solutions, obtained from pH testing, followed the order Na₂SO₄ < MgSO₄ < NaCl < CaCl₂. The molecular weight cutoff was calculated by the retention of poly(ethylene glycol) solutions with different molecular weights, and finally, the stoke radius was calculated as 1.47 nm. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41988.     

Organic solvent nanofiltration with a Poly(dimethylsiloxane) membrane: Parameters affecting its sieving properties

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.     

Recent advances in membrane hydrophilic modification with plant polyphenol-inspired coatings for enhanced oily emulsion separation

Oily wastewater, especially the emulsified one, causes serious environment pollution and poses threats to the ecosystem and resource recycling. Among various filtration media, porous polymeric membranes have gained tremendous attention in dealing with oily emulsions due to their energy-saving, cost-effective, and highly efficient features. However, to alleviate membrane fouling by oil droplets and ensure high separation efficiency, endowing membrane with superhydrophilicity and underwater superoleophobicity via facile strategy is highly desired. Taking advantages of the mild forming conditions, universality and cost-efficiency, more and more efforts have been devoted to membrane hydrophilic modification by plant polyphenol-inspired coatings in recent years. In this review, we focus on recent advances in constructing plant polyphenol-involved coatings on membrane surface for oil-in-water emulsion separation. The interactions between plant polyphenol and functional materials including amino-functionalized materials, transition metal ions and oxidants via covalent chemistry, coordination chemistry, and rapid oxidation are highlighted. In addition, the impacts of the resultant coating on the wettability, oily emulsion separation performance, and anti-oil fouling performance of the modified membrane are systematically summarized. Finally, future outlooks in membrane surface engineering with plant polyphenol-involved coatings are discussed to further broaden the research related to high-efficiency oil/water separation based on membrane technology.     

Surface modification of polyamide nanofiltration membrane by grafting zwitterionic polymers to improve the antifouling property

A simple two‐step surface modification method of polyamide nanofiltration membrane, involving the activation of amide groups by formaldehyde and the subsequent cerium [Ce (IV)]‐induced graft polymerization of zwitterionic 3‐(methacryloylamino) propyl‐dimethyl‐(3‐sulfopropyl) ammonium hydroxide) (MPDSAH) monomers, was employed to improve membrane antifouling property. The membranes before and after modification were characterized by attenuated total reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR), scanning electron microscopy, and atomic force microscopy. The changes in both surface chemical composition and morphology of membranes confirmed the successful graft polymerizations of MPDSAH onto polyamide nanofiltration membrane. The static water contact angle measurements showed that surface hydrophilicity of the modified membranes was significantly enhanced. As the MPDSAH concentration increased, the water flux of grafted membrane decreased gradually, while salt rejection increased slightly. The fouling experiments with bovine serum albumin solution demonstrated that modified membranes exhibited better resistance to protein fouling. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41144.