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1.
改变AB型单体3-氨基-5,6,9,10-四氢-[5]螺旋烯-7,8-二羰基-二甲酸酐(ATHDA)的用量,使之与4,4''-(4,4''-异亚丙基二苯氧基)双(邻苯二甲酸酐)(BPADA)和2-氨基二苯醚(ODA)共聚,制备出一系列ATHDA结构单元含量不同的聚醚酰亚胺PEI-ABx(x分别为0%、5%、10%、15%、20%,表示以BPADA和ODA的总质量为基准计算得到的ATHDA的投料比)。采用FTIR、1HNMR、DSC、DMA、TGA 等对聚合物进行了表征。结果表明,所制备的PEI-ABx特性粘度在0.60~0.87 dL/g之间,均具有良好的成膜性,且该系列聚合物均具有优异的溶解性;由DMA所测得的玻璃化转变温度(Tg)在228~256 °C之间,N2气氛下5%的热失重温度(T5%)为505~536 °C,表明PEI-ABx具有优异的热稳定性;聚合物薄膜的拉伸强度、杨氏模量和断裂伸长率分别在41.7~88.1 MPa、1.7~2.7 GPa 和3.3%~4.8%的范围内,具有良好的机械性能。另外,聚合物分子链中的四氢-[5]螺旋烯结构可脱氢芳香化, PEI-AB20%脱氢芳香化后的聚合物Tg从256 °C提高至283 °C, T5%从531 °C提升至557 °C,表明芳香化后的聚合物耐热性得到进一步提升。 相似文献
2.
汽车尾气净化催化剂的研制及其性能的研究 总被引:3,自引:1,他引:3
研究了 Cu- Co- Ce- Mn- Pd- K- O/γ- Al2 O3 催化剂的活性、热稳定性等。结果表明 ,该催化剂具有低温活性高 ,热稳定性好等特点。对 CO、C6H14 氧化的 t50 % 和 t98% 分别为 1 40°C、2 60°C和 1 80°C、2 95°C。催化剂活性组分间及它们与载体间存在着协同效应。Ce O2 的引入使各活性组分以高度分散的非结晶形态存在 ,这些是催化剂低的起燃温度、高活性的主要原因。另外 ,Ce O2 和 K2 O的引入赋予催化剂 90 0°C高温不烧结的良好热稳定性 相似文献
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4.
Cl2 O7是无色油状液体 ,熔点 1 82°K,沸点35 5°K。是一种强氧化剂。原有的制备 Cl2 O7的方法[1-3 ] 存在着不少缺点 :产品 Cl2 O7浓度低 ,仅利用一种溶剂 ( CCl4)作为Cl2 O7的溶剂 ,而且 CCl4的结晶温度 ( - 2 3°C)相对较高 ,制备过程存在着爆炸的危险性。ОсадчаяΛИ[4]不仅对原有的制备方法进行了改进 ,而且提出了一个新的制备 Cl2 O7的方法。二种方法特别是新制法产率高 ,产品浓度高 ,质量好 ,并可进行工业规模的生产。因为在制备过程中排除了加热和蒸馏 ,所以完全没有危险。经济效益好。使用三种溶剂—— CH2 Cl2 ,C… 相似文献
5.
反应-结晶法生产对甲苯磺酸 总被引:1,自引:0,他引:1
运用部分结晶选择性原理制备对甲苯磺酸。甲苯与浓硫酸在甲苯沸腾回流(110°C)的条件下反应5h后在80°C下加水使对甲苯磺酸结晶水合物从磺化混合液中析出,而间位和邻位两种异构物留在体系中,补充原料后继续反应,体系重新达到化学平衡状态,再析出产品。如此循环反应-结晶过程,即抑制了新的间位和邻位异构物进一步产生,又使较纯的对位产物分离出体系。优化了工艺条件,结果表明,该生产工艺路线为硫酸定量反应,无废酸或甲苯排放,产品纯度大于98%,循环反应8次,收率可达90%以上。对于高选择性生产对甲苯磺酸和清洁磺化过程具有重要的意义。 相似文献
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烷基二苯醚二磺酸盐的制备与性能表征 总被引:14,自引:2,他引:12
制备了一类由刚性基团联接的特殊双亲水基型阴离子表面活性剂———十二烷基二苯醚二磺酸钠(C12-MADS)、双十二烷基二苯醚二磺酸钠(C12-DADS)及十六烷基二苯醚二磺酸钠(C16-MADS),并对其性能进行了研究。25℃时3种烷基二苯醚二磺酸钠的CMC分别为1 16×10-3、1 10×10-5和4 51×10-4mol/L,γCMC分别为44 9、43 5和46 8mN/m,C12-MADS和C16-MADS在浓度分别为2 21×10-2和3 80×10-2mol/L时的胶束聚集数(Nm)分别为24和29。合成的烷基二苯醚二磺酸钠在质量分数高达0 1的无机酸、碱和盐溶液中保持稳定,发泡性低于烷基苯磺酸钠(LAS),但乳化性能优于LAS。C12-MADS在650mg/L硬水中去污比值为14 05%,明显高于LAS(7 18%)。C12-MADS和C12-DADS在4d后的生物降解度≥90%。该类表面活性剂具有优良的应用性能。 相似文献
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《世界橡胶工业》2006,33(1):55-58
一、轮胎具有防臭氧龟裂和防褪色性的胶料配方及其制成的轮胎Jpn.Kokai Tokkyo Koho JP 2003 292,684(Cl.C08L21/00)该专利介绍的胶料配方含有100份天然橡胶、异戊二烯橡胶、丁二烯橡胶和/或丁苯橡胶以及0.1份~10份聚烯烃蜡,该聚烯烃蜡用差示扫描量热法测得的熔点为60°C~100°C,用凝胶渗透色谱法测得的数均分子量Mn为400~5000。胶料配方中含有50份天然橡胶(牌号RSS 1)、50份丁二烯橡胶(牌号Nipol BR 1220)、50份炭黑、2份硫黄和2份聚烯烃蜡(该聚烯烃蜡的熔点为80°C,数均分子量Mn为500,在制备过程中有异丁基溴化铝、三苯基碳硼酸四… 相似文献
8.
2,2-二羟甲基丁酸的合成 总被引:4,自引:0,他引:4
在碱性催化剂的存在下,甲醛和丁醛进行羟醛缩合反应,制备2,2-二羟甲基丁醛。再以过氧化氢为氧化剂,通过氧化,结晶,重结晶,得到2,2-二羟甲基丁酸的白色晶体。研究了原料摩尔比、反应温度、反应时间、溶剂等反应参数的影响。当甲醛与丁醛的摩尔比为2.2∶1,催化剂(10%NaOH)用量为10mL时,在15°C反应5h,2,2-二羟甲基丁醛的最高摩尔收率可达到58.5%;然后加入180mL溶剂(水)和64mL过氧化氢,在70°C反应8h,2,2-二羟甲基丁酸的最高摩尔收率为66.0%。用红外光谱和核磁共振证明了该化合物的结构。 相似文献
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凝胶网格法制备纳米CdFe2O4粉体及其对CH3SH的气敏性 总被引:1,自引:0,他引:1
以无机盐为原料,采用凝胶网格法合成了尖晶石型复合氧化物CdFe2O4的前驱体,并在700°C热处理后得到了纳米尺寸CdFe2O4粉体,利用XRD和TEM对粉体的形貌、结构进行了表征。研究表明,用凝胶网格法制备的CdFe2O4结晶良好,粒度分布均匀,平均粒径为21.3 nm。以CdFe2O4纳米粉体为原料制备了厚膜型气敏元件。CdFe2O4是电子导电型半导体,当加热电压为6.5 V时,该元件对甲硫醇具有较高的灵敏度,较好的稳定性和选择性。 相似文献
10.
报道了用化学溶液沉积法采用价格低廉的原料在电阻率为 6~ 9Ω·cm的 n型 Si( 1 0 0 )衬底上生长 Bi4 Ti3 O12 铁电薄膜 ,并对薄膜的性质进行了研究。结果表明此制膜工艺简单 ,成本低 ,制备的 Bi4 Ti3 O12 铁电薄膜具有较低的结晶温度 ,且薄膜均匀 ,致密 ,无裂纹。在 650°C下退火 30 min时得到的 Bi4 Ti3 O12 铁电薄膜具有良好的绝缘性和铁电性 ,薄膜的剩余极化 Pr=4.9μC/cm2 ,矫顽电场 Ec=87k V/cm 相似文献
11.
Hydrogenolysis of diphenyl ether was investigated at 550°C and 620°C and at pressures up to 1850 psig. Primary interest was the elucidation of cracking patterns at a hydrogen to diphenyl ether molar ratio of 2:1. The primary reaction was C—O—C bond cleavage resulting in the formation of benzene and phenol. The secondary reaction was ring cracking resulting in the formation of gaseous components namely, carbon monoxide, carbon dioxide and lighter hydrocarbons. 相似文献
12.
Fan Wang Jinfeng Xu Jian Zhang Farong Huang Yongjia Shen Lei Du 《Polymer International》2006,55(9):1063-1068
Two kinds of novel compounds, diphenylacetylene diphenyl ether (DPADPE) and diacetylene diphenyl ether (DADPE), were prepared and polymerized under heating. Raman, DSC and 13C CP/MAS NMR analyses were used for studying the polymerization reaction. DPADPE and DADPE have melting points at 190 and 79 °C, with exothermic peaks of the DSC curves at 375 and 215 °C for curing, respectively. Raman and 13C CP/MAS NMR spectra show that DPADPE could be cured at a temperature higher than 300 °C and DADPE at a lower temperature of higher than 150 °C. The kinetic parameters for the thermal crosslinking reactions were obtained by the Ozawa method and the results show that the apparent activation energy is 152 kJ mol?1 for DPADPE and 109 kJ mol?1 for DADPE. An ene–yne Straus product appears in the cured DADPE, whereas this product has not been identified in the cured DPADPE. The cured DPADPE and DADPE demonstrate good thermal and thermo‐oxidative stability. Copyright © 2006 Society of Chemical Industry 相似文献
13.
A new method of synthesis of poly(ether carbonate)s based on interchange reactions of dihydroxy compounds with alkylene and arylene diphenyl dicarbonates containing ether group was presented. The diphenyl dicarbonate monomers were prepared from phenyl chloroformate and dihydroxy compounds containing ether group (e.g., diethylene glycol, bis(2‐hydroxyethyl ether) of bisphenol A, and 4,4′‐oxydiphenol). The process consisted of a precondensation step under a stream of dry argon followed by a melt polycondensation at 230 or at 250°C under vacuum. Four series of poly(ether carbonate)s were prepared using this approach. Using alkylene and arylene diphenyl dicarbonate‐containing ether groups as monomers, the polycondensation reaction with dihydroxy compounds led to the formation of poly(ether carbonate)s having inherent viscosity values up to 0.56 dL/g and high thermal stability. The glass transition temperature values of polycarbonates were in the range 7–122°C. The polymers were characterized by inherent viscosity and spectroscopic (Fourier transform infrared spectroscopy and 1H‐NMR and 13C‐NMR) and thermal (differential scanning calorimeteric and thermogravimetric) methods. This approach may permit the use of diphenyl dicarbonates containing other organic functional groups for the synthesis of polycarbonates containing those groups. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
14.
4,4′‐Bis(4‐phenoxybenzoyl)diphenyl was prepared by the Friedel–Crafts reaction of 4‐bromobenzoyl chloride and diphenyl followed by condensation with potassium phenoxide. Novel aromatic poly(ether ketone diphenyl ketone ether ketone ketone)s were obtained by the electrophilic Friedel–Crafts solution copolycondensation of 4,4′‐bis(4‐phenoxybenzoyl)diphenyl with a mixture of isophthaloyl chloride and terephthaloyl chloride over a wide range of isophthaloyl chloride/terephthaloyl chloride molar ratios in the presence of anhydrous aluminum chloride and N‐methylpyrrolidone in 1,2‐dichloroethane. The influence of the reaction conditions on the preparation of the copolymers was examined. The copolymers were characterized with different physicochemical techniques. Because of the incorporation of diphenyl, the resulting copolymers exhibited outstanding thermal stability. The glass‐transition temperatures were above 174°C, the melting temperatures were above 342°C, and the 5% weight loss temperatures were above 544°C in nitrogen. All these copolymers were semicrystalline and insoluble in organic solvents. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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High molecular weight poly(phenylene sulfide ether) (PPSE) was successfully synthesized by reaction of 4,4′‐dihydroxy diphenyl sulfide with 4,4′‐dichloro diphenyl sulfide in N‐methyl‐2‐pyrrolidone (NMP). The influence of polymerization conditions on the intrinsic viscosity and yield of PPSE was investigated and the optimized reaction condition was concluded. Reactions at about 180°C for 6 h along with sodium benzoate as an additive and monomer concentration of 0.588 mol/L NMP were found to produce the highest intrinsic viscosity (0.55 dL/g). Longer reaction time and/or higher temperature reduced the intrinsic viscosity and yield of the resulting product, probably due to side reactions, such as reductive dehalogenation and chemical degradation. X‐ray diffraction indicated that the polymer possessed of orthorhombic cell and had a high crystallinity of 65.8%. The high molecular weight PPSE is a crystalline polymer with Tm of 252°C and Tmc of 224°C. The polymer shows good chemical resistance, but is soluble in organic amide, halo‐hydrocarbon and oxohydrocarbon solvent at a temperature over 150°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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Density functional theory (DFT) calculation and pyrolysis gas chromatography mass spectrometry (PyGC/MS) analysis were combined to investigate the thermal degradation behavior of polysulfone, poly(ether sulfone) and poly(phenylene sulfone). A series of pyrolysis temperatures from 500°C to 700°C with the interval of 50°C were chosen for their PyGC/MS analyses, and the obtained results indicate that phenol as a pyrolysis product is preferentially generated over SO2 during their pyrolysis. In DFT calculations, their bond dissociation energies and first-stage fragmentation products diradicals at various temperatures were calculated by the M05-2x method, and their preferentially produced pyrolysates estimated from the obtained results are in accordance with the experimental findings. 相似文献
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Selected model compounds representing coal structural entities were studied under the conditions of HF-BF3-H2 catalysed mild coal liquefaction. Bibenzyl and diphenylmethane gave near quantitative conversion at room temperature without added hydrogen. Biphenyl, however, required hydrogen pressure at 150 °C and gave a conversion of only ≈30%. Among the model compounds containing ether linkages, dibenzyl ether and benzyl phenyl ether gave quantitative conversion at room temperature without added hydrogen. Diphenyl ether in contrast was converted (≈70% yield) only under hydrogen pressure at 155 °C. Sulphur- and nitrogen-containing model compounds were also studied. At 95 °C in the absence of hydrogen, benzyl phenyl sulphide and dibenzyl sulphide gave over 95% conversion. On the other hand diphenyl sulphide and diphenyl disulphide required hydrogen pressure at 150 °C to give conversions of ≈95%. Quinoline gave a conversion of ≈20% under hydrogen pressure at 150 °C. The formation of condensation products in these conversion processes could be suppressed by the use of a good hydrogen donor, such as isopentane. 相似文献
18.
介绍了用二苯醚为原料,经浓硫酸磺化、再与三氯氧磷反应制备4,4′-氧化双苯磺酰氯的方法。与二苯醚直接同氯磺酸反应的制法相比,产率高、产品纯,并易于工业化。 相似文献
19.
A new unsymmetrical diamine monomer, 2,4‐diaminophenyl [4′‐(2′′,6′′‐diphenyl‐4′′‐pyridyl)phenyl]ether, was successfully synthesized by nucleophilic substitution of 1‐chloro‐2,4‐dinitrobenzene with 4‐(2′,6′‐diphenyl‐4′‐pyridyl) phenol. The diamine monomer was characterized by FTIR, 1H and 13C NMR, and elemental analysis techniques and used for the preparation of novel polyimides (PIs) by reaction with commercially available tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bicyclo[2.2.2]‐oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride. These PIs with inherent viscosities ranged from 0.43 to 0.48 dL/g were readily soluble in many organic solvents and afforded tough and flexible films by solution casting. These polymers exhibited Tgs between 237 and 294°C, and 10% weight loss temperatures in excess of 500°C with up to 56% char yield at 600°C in air. Their maximum fluorescence emission in dilute (0.2 g/dL) NMP solution appeared at 450 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献