四溴双酚A的臭氧氧化降解研究

通过小试试验,考察了臭氧对水体中四溴双酚A的处理效果,并研究了臭氧浓度、pH值和温度等因素对处理效果的影响,试验结果表明:臭氧可以实现对四溴双酚A快速去除,反应符合假一级动力学模型,四溴双酚A的去除率随臭氧投量升高而增大;较低的pH和温度有利于臭氧对四溴双酚A的去除.GC-MS分析发现,四溴双酚A降解中间有机产物主要包...     

臭氧氧化四溴双酚A过程中溴离子和溴酸盐生成的影响因素

为了研究控制四溴双酚A（TBBPA）臭氧化过程中溴酸盐生成的影响因素,通过实验对不同的水质参数和臭氧投加量条件下臭氧氧化TBBPA过程中溴离子（Br－）及溴酸根离子（BrO3－）的生成量进行了考察。结果表明,臭氧氧化TBBPA生成BrO3－分为两阶段：第一阶段为臭氧氧化降解TBBPA生成Br－,即Br－累积阶段;第二阶段为臭氧化Br－生成BrO3－,即BrO3－生成阶段。Br－及BrO3－的生成量随着TBBPA初始浓度的增加而增加,生成速率随臭氧投加量增加而提高。25～55 ℃条件下反应40 min后,BrO3－生成量随温度升高增加了4.5倍。pH值8～11内,pH值降低对Br－及BrO3－生成量有明显的抑制作用。     

四溴双酚A的合成研究

四溴双酚A以95%无水乙醇为溶剂,以双酚A和溴素为原料合成。在双酚A与溴素摩尔比一定的条件下,通过改变反应时间进行合成实验,结果表明:最佳反应时间2.5 h;在反应时间一定的条件下,通过改变双酚A与溴素摩尔比进行合成实验,结果表明:最佳原料摩尔比1∶2.6。在此反应条件下合成具有高收率,高质量,操作简便等优点。     

过氧溴化法制造四溴双酚A研究

介绍了双酚A溴化生成四溴双酚A的反应过程,对过氧溴化法的工艺条件和影响产品质量及收率的多种因素进行了研究,还对中试情况作了简要叙述。     

阻燃剂四溴双酚A的环境友好合成工艺研究

研究了过氧化氢存在下以双酚A与液溴为原料合成四溴双酚A的工艺条件 ,考察了n(Br2 )∶n(双酚A)、n(H2 O2 )∶n(Br2 )、反应时间等因素对反应的影响 ,并通过正交实验 ,优化了合成工艺条件。实验表明 :n(Br2 )∶n(双酚A) =2 2 0∶1 0 0 ,n(H2 O2 )∶n(Br2 ) =1 10∶1 0 0 ,反应温度15～ 2 5℃ ,每克双酚A加水 3mL时收率接近 99% ,溴利用率达 99%     

亚硝酸钠/盐酸催化氧气氧化碘化芳烃、醚、酚化合物

以廉价易得的盐酸/亚硝酸钠为催化剂,碘为碘化试剂,通过分子氧,氧化碘化芳烃、醚、酚的活泼芳香底物,发展了温和条件下高效碘化方法。以苯甲醚为模型底物,系统考察了影响反应的因素,确定的最佳反应条件为:20℃氧气条件下,1,2-二氯乙烷(DCE)为溶剂,n(苯甲醚)∶n(碘)∶n(亚硝酸钠)∶n(HC l)=1∶0.515∶0.05∶0.1。该方法碘原子经济性好,催化剂廉价易得,反应时间大为缩短,选择性好、转化率高,副产物仅为水,容易处理,绿色环保、易于工业化;通过反应机理验证实验,提出了可能的催化循环机理。     

低分子量四溴双酚A型环氧树脂溶剂萃取提纯研究

用溶剂萃取法提纯低分子量四溴双酚A型环氧树脂时，有机溶剂萃取产品所得萃取液水洗易发生乳化现象。本文探索了避免乳化发生的条件，获得了高质量树脂产品，减少了产品因水洗造成的损失。     

甲醇法生产四溴双酚A新工艺

甲醇是生产四溴双酚A合适的溶剂 ,对产品质量有影响的因素有 :溶液温度、酸度和加溴速度。在低温和高酸度下 ,控制一定的加溴速度 ,可以生产出高质量的产品。保持体系一定含水量 ,抑制HBr与甲醇反应 ,用H2 O2 氧化副产品HBr ,可有效降低溴代甲烷的生成量 ,提高溴素利用率。在 85%甲醇水溶液中 ,当原料的配比为 :n(双酚A)∶n(Br2 )∶n(H2 O2 ) =1∶2 .2 3∶1时 ,得到的产品纯度为 99.4 % ,收率 98.5% ,色度 (APHA)为 19,无机溴和水解溴含量为 0 .0 0 4 0 % ,产品熔点≥ 180℃     

双酚A合成四溴双酚A双(2,3一二溴丙基)醚的工艺研究

将四溴双酚A和四溴双酚A双(2,3-二溴丙基)醚(简称八溴醚)两产品的工艺技术有机地结合起来,探讨了在氯苯溶剂中以双酚A为原料直接合成四溴双酚钠,并在乙醇溶剂中与氯丙烯合成中间体四溴双酚A双烯丙基醚的过程及分析了各种影响因素,开发出一条由双酚A直接制备八溴醚的工艺路线。该工艺的主要特点是四溴双酚A以钠盐的形态直接转入醚化工序,缩短了工艺流程,减少了溶剂损失。     

四溴双酚A的合成新工艺

对以次氯酸钙为氧化剂合成四溴双酚A的生产工艺做了研究,该工艺具有原料价廉易得、反应条件温和、产品收率高等优点,具有广阔的推广、应用前景。     

In situ Acidic Carbon Dioxide/Ethanol System for Selective Oxybromination of Aromatic Ethers Catalyzed by Copper Chloride

An environmentally benign carbon dioxide/ethanol reversible acidic system was developed for the copper(II)‐catalyzed regioselective oxybromination of aromatic ethers without the need of any conventional acid additive and organic solvent. Good to excellent yields together with very good regioselectivity were achieved when easily available cupric chloride dihydrate was used as catalyst and lithium bromide as the cheap and easy‐to‐handle bromine source under supercritical carbon dioxide conditions. Notably, the catalytic system worked well for a wide range of aromatic ethers including sulfides, resulting in the formation of the mono‐brominated products in high yields and exclusive regioselectivity. The alkylcarbonic acid in situ formed from ethanol and carbon dioxide is assumed to play the crucial role in the Brønsted acid‐promoted reaction, which could probably act as the proton donator, and was studied employing in situ FT‐IR technique under carbon dioxide pressure by monitoring the vibration shift of the hydroxy group of ethanol. Given with excellent bromine atom efficiency as well as no need of neutralization in waste disposal, this approach thus represents a greener pathway for the aerobic bromination of aromatic ethers. A possible catalytic cycle for the in situ alkylcarbonic acid‐assisted oxybomination and the effect of supercritical carbon dioxide, i.e., activation of alcohol and enhancement of mass transfer are also discussed.     

Oxybromination of Ethynylbenzene Catalysed by Molybdenum Complexes in Organic Solvent and in Ionic Liquids

The molybdenum(VI)‐catalysed oxybromination of ethynylbenzene was performed with hydrogen peroxide as oxidant and potassium bromide as source of bromine, in a two‐phase water/solvent system, where solvent was either dichloromethane or an ionic liquid. The selectivity was toward 1,2‐dibromostyrene when performed in water/dichloromethane. In ionic liquids better yields and shorter reaction times were obtained that, together with the complete ethynylbenzene conversion and the preferred formation of α,α‐dibromoacetophenone, make the reaction synthetically useful.     

Aerobic Oxidative Iodination of Organic Compounds with Iodide Catalyzed by Sodium Nitrite

Selective and efficient iodinations of organic compounds were achieved by an aerobic oxidative process catalyzed by sodium nitrite using potassium iodide in acidic media. Using the potasasium iodide (KI)/air/sodium nitrite (NaNO₂; cat.)/sulfuric acid (H₂SO₄) iodinating system, activated and moderately deactivated aromatic compounds were exclusively or preferentially iodinated at the para position. In protic solvents ketones and 1,3‐dicarbonyl compounds were iodofunctionalized at the α carbonyl position, while in the case of aryl methyl ketones bearing an activated aromatic ring, the regioselectivity of iodination could be directed by the solvent used. In acetonitrile (MeCN) the aromatic ring was selectively iodinated, while in aqueous rethanol (EtOH) functionalization of the methyl carbon atom took place. Alkenes were transformed to vicinal iodohydrins or vicinal iodoalkoxy derivatives following Markovnikov‐type regioselectivity and anti stereoselectivity, while 1,2‐diiodoalkenes with preferentially E orientation were formed from alkynes.     

Copper‐Catalyzed Oxybromination and Oxychlorination of Primary Aromatic Amines Using LiBr or LiCl and Molecular Oxygen

Nuclear oxybromination of unprotected aromatic primary amines catalyzed by copper(II) acetate [Cu(OAc)₂] under mild conditions has been developed, in which bromide ions are used as halogenating agents and dioxygen as a final oxidant. The catalyst shows not only high regioselectivity for para‐ or ortho‐isomers but also a remarkable chemoselectivity for monobromination. Oxychlorination of aniline can also be performed under similar conditions, albeit with lower selectivities, with N‐phenylacetamide being the main by‐product. This simple catalytic method represents ecologically benign and economically attractive synthetic pathway to expensive low‐volume aromatic haloamines.     

无金属的硝酸催化氧气氧化碘化有机分子

发展了以廉价易得的硝酸为催化剂,碘为碘化试剂,温和条件下无金属催化分子氧高效氧化碘化芳烃、醚、酚和酮类化合物的方法。全面考察了影响反应的因素,以苯甲醚为模型底物,确定其最佳反应条件为:20℃氧气条件下,1,2-二氯乙烷(DCE)为溶剂,n(苯甲醚)∶n(碘)∶n(硝酸)=10∶5.15∶2。该方法无金属催化,碘原子利用率高,原子经济性好,宽底物适应范围,绿色环保,易于工业化。     

界面缩聚法合成四溴双酚A聚碳酸酯的工艺研究

以光气和四溴双酚A(TBBPA)为原料经光气界面缩聚,合成了四溴双酚A聚碳酸酯,并对四溴双酚A与光气投料比、催化剂种类及其用量、分子量调节剂用量4个因素进行考察。优化工艺条件为:四丁基氢氧化铵为催化剂,对叔丁基酚(TBP)为分子量调节剂,n(四溴双酚A)∶n(光气)=1∶1.3,n(四溴双酚A)∶n(对叔丁基酚)=1∶0.028,n(四溴双酚A)∶n(四丁基氢氧化铵)=1∶0.022。该方法操作简单,产品分子量分布窄,易于工业化生产。     

四溴双酚A的合成及其复合阻燃效应

研究了以双酚A(BPA)为原料、NaBr—KBrO3作溴化剂合成四溴双酚A(TBA)的工艺条件,并研究了TBA及其与三聚氰胺、磷酰胺-Mg(OH)2复合对PE的阻燃性能。结果表明：TBA的最佳合成工艺为n(BPA)：n(NaBr)：n(KBrO3)=3：8．8：4．4,室温反应5．5h,回流反应2h,得到淡黄色TBA,产率99．08％,熔点170～174℃;阻燃剂对PE的合适添加量分别为ω(TBA)=15％、ω(TBA—三聚氰胺)=15％、ω(TBA—磷酰胺—Mg(OH)2]=15％。