对叔丁基氯苄的合成工艺研究

以叔丁基苯、多聚甲醛和盐酸为原料,通过氯甲基化反应制备对叔丁基氯苄。研究了投料摩尔比、反应温度、反应时间以及催化剂对产物收率的影响,优惠工艺条件为:磷酸作催化剂,叔丁基苯∶甲醛∶氯化氢=1∶3∶3(mol/mol),反应温度80～85℃,反应时间15h。     

POLYMERS WITH PENDENT FUNCTIONAL GROUPS. VI. A COMPARATIVE STUDY ON THE CHLOROMETHYLATION OF LINEAR POLYSTYRENE AND POLYSULFONE WITH PARAFORMALDEHYDE/Me3SiCl

Studies have been carried out on the chloromethylation reaction of polystyrene and polysulfone for obtaining soluble chloromethylated polymers with a high degree of substitution. The mixture of paraformaldehyde/chlorotrimethylsilane as the chloromethylation agent, stannic tetrachloride as the catalyst, and chloroform as the solvent was used for the chloromethylation reaction of these polymers. The degree of substitution and the chlorine content depend on the [SnCl₄]/[polymer structural unit], [Me₃SiCl]/ [polymer structural unit] molar ratios and the reaction time.     

高交联大孔吸附树脂氯甲基化研究

以无水ZnCl2为催化剂,以自制1,4-二氯甲氧基丁烷(BCMB)为氯甲基化试剂,对高交联度的非极性大孔吸附树脂D101进行氯甲基化反应研究。得到该氯甲基化的最佳工艺条件:m(D101)∶m(BCMB)∶m(CCl4)=1∶4∶18.6,溶胀时间12h,反应温度50℃,反应时间14h,以无水ZnCl2为催化剂,在该工艺条件下制得氯质量分数为4%的树脂,为以后树脂的改性、功能化和进一步研究大孔吸附树脂吸附分离规律提供了实验基础。     

Profile of extended chemical stability and mechanical integrity and high hydroxide ion conductivity of poly(ether imide) based membranes for anion exchange membrane fuel cells

We designed and synthesized a poly(ether imide) (PEI) membrane that has good chemical and mechanical stabilities. Alkalized PEI (A-PEI) membrane was fabricated by solution casting of chloromethylated PEI (CM-PEI) followed by quaternization and alkalization. The chemical structure of the synthesized polymers was verified by proton nuclear magnetic resonance (¹H NMR) and Fourier-transform infrared spectroscopy (FT-IR). Physiochemical properties of the membrane such as ion exchange capacity, water uptake, and swelling ratio were investigated. The membranes with a high degree of chloromethylation (DC) exhibited elevated hydroxide ion conductivity in range of 6.7–44.2 mS/cm at 90 °C under 100% relative humidity (RH). The hydrophilic-hydrophobic phase separation was verified by atomic force microscope (AFM) and small angle X-ray scattering (SAXS) measurements. Chemical stability was evaluated by measuring the durability of membranes while they were soaked in oxidative and alkaline solutions at 60 °C for 200 h.     

Hydrogen production by electrochemical methanol reformation using alkaline anion exchange membrane based cell

Electrochemical methanol reformation (ECMR) is an alternative promising technology for producing hydrogen at low energy consumption compared to water electrolysis. In this process, solid polymer electrolyte Nafion® is widely employed, due to its superior proton conductivity. However, major limitations are the utilisation of expensive platinum based catalysts, high cost of the above membrane and the crossover of methanol through the polymer electrolyte membrane. In the present work, attempt has been to made to use low cost polymer electrolyte membrane and less noble electro catalyst. A series of Anion Exchange Membranes (AEM) are synthesized from Poly (2, 6-dimethyl-1, 4-phenylene oxide) (PPO) for its application in ECMR. PPO is successfully made into anion conducting by chloromethylation followed by quaternization. Two AEM's are synthesized by optimizing chloromethylation reaction time to 5 h and quaternization time to 5 and 8 h and are labelled as QPPO (C5, Q5) and QPPO (C5, Q8) respectively. Further, with the view to improve the anion conductivity further, composite AEMs are prepared by incorporating inorganic anion conducting quaternized graphene oxide particles in the matrix of PPO and QPPO (C5, Q8) polymers separately to obtain two polymers PPO/QGO and QPPO/QGO. The anionic conductivity of PPO/QGO and QPPO/QGO polymer is 1.2 × 10⁻⁴ and 1.5 × 10⁻⁴ S cm⁻¹ respectively. Both the membranes are subjected as electrolyte for ECMR application using membrane electrode assembly made by with in house synthesized nitrogen doped graphene supported Pd catalyst (Pd/NG) as anode catalyst and commercial Pt/C as cathode catalyst. The performance of composite membrane was compared with the commercial Fumasep® FAA anion exchange membrane. The polarization studies of ECMR cell with composite membrane shows comparable performance with that of commercial Fumasep® FAA-2 FAA membrane. The durability of the membrane(s) in the electrolysis environment was tested for about 20 h.     

Anion conductive tetra-sulfonium hydroxides poly(fluorenylene ether sulfone) membrane for fuel cell application

A series of anion exchange membranes of poly (fluorenylene ether sulfone) containing tertiary sulfonium hydroxide-functionalized fluorenyl groups were synthesized by sequential polycondensation, chloromethylation, substitution with dimethyl sulfide and ion exchange. They showed excellent solubility in polar aprotic solvents. Consequently, flexible and tough alkaline membranes with varying ionic contents were obtained by an anion exchange of tertiary sulfonium chloride polymers with 1.0 M KOH at room temperature. Different levels of substitution were performed to achieve high ionic conductivity as well as upholding the membranes’ mechanical stability. The tertiary sulfonium membranes demonstrated lower water uptake compared to quaternary ammonium membrane. High hydroxide ion conductivity was achieved up to 18.3 mS cm^?1 at 80 °C with the membrane of the highest ion exchange capacity (IEC, 1.51 mmol g^?1). The resulting alkaline polymers were characterized by ¹H NMR, FT-IR, thermogravimetric analysis (TGA), water uptake, IEC, atomic force microscopic (AFM) images.     

含螯合功能基高分子的合成表征及应用

本文利用聚苯乙烯与多聚甲醛、三氯化磷在氯化锌催化下，生成氯甲基化聚苯乙烯，氯甲基化聚苯乙烯与２－巯基－５－甲基－１，３，４－噻二唑在有机碱存在下反应，生成具有螯合功能基的功能高分子，利用元素分析确定其氮含量为１１．２％，对比噻二唑与功能高分子的红外光谱图，确定了其结构，该功能高分子与许多过渡金属离子如Ａｇ＾＋Ｃｕ＾２＋＋Ｃｕ＾＋Ｆｅ＾３＋及Ｃｏ＾３＋络合生成高分子金属络合物，因而，在环保上有望用于     

Anion-conducting ionomers: Study of type of functionalizing amine and macromolecular cross-linking

Anion exchange membranes (AEM) were prepared by chloromethylation and amination of polysulfone (PSU) and polyphenylsulfone (PPSU). The reaction pathways were studied by ¹H and ¹³C NMR spectroscopy and ab-initio calculations. Various amines were used, including trimethylamine (TMA), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and 1,4-diazabicyclo[2.2.2]octane (DABCO) to study the influence of the molecular volume and the stabilizing effect of a delocalization of the positive ammonium ion charge on a second nitrogen. Furthermore, the effect of a solvothermal cross-linking on the stability of AEM was investigated. The alkaline stability, measured after treatment in 2 M KOH at 60 °C during 168 h, is improved by DBN and polymer reticulation. The ionic conductivity in water reaches values above 10 mS/cm with DABCO. The hydroxide ion mobility depends linearly on the hydration number.     

A novel phosphoric acid loaded quaternary 1,4-diazabicyclo-[2.2.2]-octane polysulfone membrane for intermediate temperature fuel cells

Phosphoric acid loaded quaternary 1,4-diazabicyclo-[2.2.2]-octane (DABCO) polysulfone was synthesised with different degrees of substitution (DS) and the membranes were characterized. The polymer structure was investigated using NMR and FT-IR spectra. The effect of DS on ionic conductivity and fuel cell performance are described. Conductivities of 0.12 and 0.064 S cm⁻¹ were achieved for the high degree of substitution membrane (DS106) and low degree of substitution membrane (DS58), respectively. Fuel cell tests gave a high power output of 400 mW cm⁻² using H₂ and O₂ at 150 °C and atmospheric pressure. Therefore, PA/QDPSU membrane has potential applications for intermediate temperature fuel cells (ITFCs).