酯交换法合成碳酸二苯酯催化剂的研究

碳酸二苯酯是重要的有机中间体,应用于塑料工业。酯交换法合成碳酸二苯酯是替代光气法的新型绿色合成工艺。笔者概述了碳酸二苯酯酯交换法的合成工艺,并对催化剂研究作了介绍。     

酯交换法合成碳酸二苯酯研究进展

对碳酸二苯酯合成用催化剂、合成工艺、反应装置等进行了综述。认为国内应加强酯交换法合成碳酸二苯酯的基础研究 ,尽快实现其产业化     

酯交换合成碳酸二苯酯催化剂的研究进展

对近年来碳酸二甲酯和苯酚酯交换合成碳酸二苯酯的催化剂体系进行了较为系统的概述,包括均相催化剂体系(碱或碱金属化合物、Lewis酸、锡和钛的有机化合物等)和多相催化剂体系(各种负载型、金属氧化物、水滑石等),认为开发有机锡、有机钛配合物催化剂以及将其固载化是碳酸二甲酯与苯酚酯交换反应合成碳酸二苯酯催化剂研究的重要方向.     

Modeling the continuous melt transesterification of bisphenol-A and diphenyl carbonate in a continuous stirred tank reactor

A model of continuous melt transesterification of bisphenol-A and diphenyl carbonate in a continuous stirred tank reactor is developed using phase equilibria assumption and the method of molecular weight moments. The model equations can be simplified into a polynomial system that has 17 equations and 17 unknowns. Solution of the polynomial system gives out almost every aspects of the continuous transesterification process. Molecular weight and polydispersity index, end group ratio of hydroxyl to phenyl carbonate, contents of molecular species, and lost diphenyl carbonate fractions are studied in different operation parameters.     

碳酸二甲酯和乙酸苯酯合成碳酸二苯酯催化剂研究进展

综述了碳酸二甲酯和乙酸苯酯合成碳酸二苯酯工艺路线及其反应机理,并对该反应的催化剂体系进行了系统的概述,包括均相催化剂体系(锡和钛的有机化合物等)和多相催化剂体系(MoO3和WO3等金属氧化物)。并分析了以锡、钛以及金属氧化物作催化剂时合成碳酸二苯酯的优势和劣势;指出固载化的有机锡/有机钛与其他金属氧化物的复合化合物是今后碳酸二甲酯和乙酸苯酯合成碳酸二苯酯催化剂的重要研究方向。     

Role of sulfonic acids in the Sn-catalyzed transesterification of dimethyl carbonate with phenol

Diphenyl carbonate, the key intermediate of the non-phosgene polycarbonate manufacturing process, can be produced by the transesterification of dimethyl carbonate with phenol in the presence of dibutyltin oxide. The use of an alkyl or aryl sulfonic acid in conjunction with dibutyltin oxide significantly enhances the activity of dibutyltin oxide. ¹⁹F and ¹¹⁹Sn NMR studies suggest the formation of tin complex containing strongly electrophilic sulfonate ligand from the reaction of dibutyltin oxide with alkyl or aryl sulfonic acid. Various factors affecting the transesterification of dimethyl carbonate with phenol were investigated.     

Synthesis of diphenyl carbonate from dimethyl carbonate and phenol using O2-promoted PbO/MgO catalysts

Various heterogeneously supported PbO catalysts were prepared for the synthesis of diphenyl carbonate (DPC) by transesterification of dimethyl carbonate (DMC) with phenol. MgO was found to be the best support, and the modification by oxygen further enhanced the catalytic activities of PbO/MgO catalysts. Several parameters affecting the transesterification were investigated. The yields of methylphenyl carbonate (MPC) and DPC reached 10% and 26.6%, respectively, over 10 wt% O₂-promoted PbO/MgO catalyst which was prepared by impregnation method. X-ray diffraction (XRD), differential thermal analysis (DTA) and Brunauer–Emmet–Teller (BET) technique were employed for the characterization of prepared catalysts. It was discovered that the structure and the oxidation states of lead species in PbO/MgO catalysts changed after the promotion by oxygen.     

酯交换法合成碳酸二苯酯的反应工艺

简要介绍了酯交换法合成碳酸二苯酯的反应原理。对碳酸二苯酯合成及碳酸二甲酯/苯酚分离法、分区反应法、连续法、反应精馏法和偶联法5种酯交换法合成碳酸二苯酯的反应工艺进行了详细讨论。其中反应精馏法及偶联法是创新的工艺,其反应工艺简单,原料利用率高,碳酸二苯酯的产率和选择性均很高。     

Multistage melt polymerization of bisphenol-A and diphenyl carbonate to polycarbonate

A multistage melt polycondensation of bisphenol-A and carbonate has been studied experimentally using LiOH·H₂O catalyst. The reaction process consists of batch and semi-batch periods with different temperature and pressure conditions. It was observed that a small amount of diphenyl carbonate lost from the reaction mixture by vaporization had little effect on the molecular weight in the batch reaction period but the efficiency of subsequent low-pressure semibatch polycondensation was affected by the change in the mol ratio of the phenyl carbonate group to the hydroxyl end group. A molecular species model developed for the multistage process was used to analyze the kinetics of the polycondensation process. The composition of the reaction mixture was analyzed of HPLC and compared with model simulations. In particular, the effect of evaporative loss of diphenyl carbonate on the progress of reaction is discussed in detail. © 1993 John Wiley & Sons, Inc.     

酯交换合成碳酸二苯酯反应及催化剂研究进展

介绍了碳酸二甲酯与苯酚酯交换合成碳酸二苯酯的反应热力学。总结了近年来该类催化剂研究的新进展。对酯交换反应的平衡限制问题和选择性问题进行了详细的讨论。根据对反应热力学的分析,指出避开平衡限制的合理途径是采用酯交换-歧化二步法工艺路线,而高选择性地得到碳酸二苯酯取决于催化剂的性质。通过分析酸碱催化作用在酯交换反应中的差异,认为碱催化是副产物苯甲醚生成的主要原因,Lewis酸性的催化剂有利于碳酸二苯酯的高选择性。最后对国内研究现状进行了评价和展望。     

聚碳酸酯非光气法合成工艺研究进展

综述了近年来聚碳酸酯的酯交换法合成工艺的研究进展,着重阐述了其预聚反应动力学,介绍了该工艺中传热传质等因素对聚合过程的影响以及国内外相关研究现状和研究前景。     

酯交换法合成碳酸二苯酯热力学和催化剂研究进展

碳酸二甲酯和苯酚酯交换合成碳酸二苯酯是一条绿色的化工合成过程,但该反应的热力学平衡常数小,除采用催化蒸馏反应外,还必须选用合适的高活性和选择性的催化剂。在目前研究的均相有机钛和有机锡比非均相催化剂具有较好的活性和选择性,而且其复合催化剂性能较佳。在此基础上进一步开发研究钛 锡非均相催化剂有可能取得重要进展。     

碳酸二甲酯与苯酚酯交换合成碳酸二苯酯热力学分析

用分子模拟软件M aterial stud io、工艺过程模拟软件ChemCAD结合Benson基团贡献法,计算了碳酸二甲酯与苯酚酯交换合成碳酸二苯酯的反应焓变、反应熵变、吉布斯自由能变及平衡常数。结果表明,该反应为吸热反应,升高温度有利于DPC的生成。反应的热力学平衡常数很小,为了提高DPC收率,必须及时移走副产物甲醇。     

TiO2 -GO催化DMC与苯酚酯交换合成碳酸二苯酯

采用氧化石墨烯(GO)改性制备了TiO_2-GO催化剂,用于催化碳酸二甲酯与苯酚酯交换合成碳酸二苯酯。XRD、TEM、XPS、Py-TPD表征结果显示,GO有效促进了活性组分TiO_2的分散;GO的电子效应改变了催化剂中Ti物种的电子环境,促进了活性物种Ti(Ⅳ)的形成;GO改性的催化剂中,中强酸酸位的比例明显增加。催化剂中有效活性位增加,有利于酯交换反应产物的生成。催化反应结果表明,TiO_2-GO催化剂中GO不仅作为载体,同时起到了电子助剂的作用。当催化剂中GO质量分数为50%时,150～180℃下反应9 h后,苯酚转化率可达41.8%,酯交换总选择性为99.9%。     

n-Bu2SnO催化酯交换合成碳酸二苯酯的研究

研究比较了 n-Bu2 Sn O、Ti( OC4H9) 4、Al Cl3、Zn Cl2 四种化合物催化酯交换合成碳酸二苯酯 ( DPC)的催化性能 ,其中n-Bu2 Sn O的催化活性最高。在常压下 ,160～ 190℃时 ,n(苯酚 )∶n(碳酸二苯酯 )∶ n( n-Bu2 Sn O) =4∶ 1∶ 0 .0 4,反应时间 14 h,碳酸二甲酯 ( DMC)的转化率为 48.5 % ,DPC的产率为 43 .0 % ,碳酸甲苯酯 ( MPC)产率 5 .5 %。 DPC的选择性 88.7% ,无苯甲醚生成     

Synthesis of diphenyl carbonate from compressed carbon dioxide and phenol without use of organic solvent

Diphenyl carbonate (DPC) was synthesized from CO₂ and phenol catalyzed by Lewis acids. Compressed CO₂ was used as reactant and solvent. It was found that the conversion of phenol and the yield of DPC are dependent on the metal center of Lewis acids, and zinc halides have better catalytic performance than aluminum halides. The reaction of CO₂ with phenol is sensitive to pressure, temperature, and reaction time, and it is improved using triethylamine as acid acceptor. A 31.7% DPC yield was obtained under optimized reaction conditions: 9 MPa at 100 °C for 3 h.     

Efficient synthesis of 1,6-hexamethylene diurethane through coupling transesterification and methoxycarbonylation with methyl phenyl carbonate as intermediate

A reaction coupling system of transesterification and methoxycarbonylation with methyl phenyl carbonate (MPC) as intermediate was established to efficiently prepare 1,6-hexamethylene diurethane (HDU) from 1,6-hexamethylene diamine (HDA). The feasibility of the system was explored using the thermodynamics analysis, the reaction mechanism and the experiment results. The optimal reaction was carried out to get higher HDU yield. The thermodynamic analysis showed that the methoxycarbonylation of HDA with MPC, the Gibbs free energy of which was negative, was a spontaneous process. Furthermore, the equilibrium constant of the methoxycarbonylation of HDA with MPC was much greater than that of the transesterification of dimethyl carbonate (DMC) with phenol, so the reaction coupling could be realized under mild conditions. The reaction mechanism analysis indicated that phenoxy anion was the key species for reaction coupling. Higher MPC concen-tration was detected when sodium phenoxide was used as transesterification reactant with DMC, since the phenoxy anion of sodium phenoxide could be dissociated more easily. Sodium phenoxide was more suitable to prepare HDU through reaction coupling. A yield of HDU as high as 98.3%could be reached under the optimal con-ditions of mPhONa/mDMC=0.027 and nDMC/nHDA=8/1 at 90 °C in 2 h.     

Ti（OC4H9）4催化酯交换合成碳酸二苯指的研究

研究了以Ｔｉ（ＯＣ４Ｈ９）４为催化剂,苯酚与碳酸二甲酯（ＤＭＣ）经酯交换法合成碳酸二苯酯（ＤＰＣ）的工艺。在常压下,１６０～１９０℃,当ｎ（Ｔｉ（ＯＣ４Ｈ９）４：ｎ（ＰｈＯＨ）＝０．０１２：１,ｎ（ＰｈＯＨ）：ｎ（ＤＭＣ）＝４：１,反应时间８ｈ,总转化率为２８．３％,ＤＰＣ的产率为２５．３％,碳酸甲苯酯（ＭＰＣ）的产率为３．０％,产物中无苯甲醚,ＤＰＣ的选择性为８９．４％。     

碳酸钾催化酯交换合成碳酸二丁酯的研究

研究了碳酸二甲酯（DMC）与正丁醇（n-BuOH）酯交换合成碳酸二正丁酯（DBC）的反应，筛选出合成碳酸二正丁酯的催化剂。考察了物料配比、温度和时间诸因素对反应的影响。结果表明，K₂CO₃具有较好的催化活性和选择性。得出了该反应最佳工艺条件：常压，反应温度140 ℃，反应时间4 h，n(DMC)∶n(n-BuOH)=1∶3。在催化剂用量为原料总质量的1%的条件下，DMC转化率为89.1%，DBC收率为86.9%，DBC选择性为97.6%，甲基丁基碳酸酯（MBC）收率为2.2%，碳酸二异丁酯(DIBC)的收率为70.0%，碳酸二叔丁酯（DTBC）收率为10.3%。