叔胺从硫酸氢钾溶液中萃取硫酸机理的研究

本文研究了叔胺Ｎ２３５从硫酸氢溶液中萃取硫酸的平衡规律，找到了相应的萃取机理。     

13C NMR定量分析一乙醇胺（MEA）与CO2的吸收和解吸特性

13C NMR是一种有效的测定有机胺与CO2反应过程中离子浓度变化的检测手段。本文采用13C NMR分析了一乙醇胺(MEA)吸收与解吸CO2过程,吸收与解吸实验温度分别在313K和393K下进行。结果表明,吸收CO2过程中生成了MEA氨基甲酸盐、质子胺MEAH+与HCO3-/CO32-,并且CO2与MEA反应时先生成MEA氨基甲酸盐,当溶液吸收的CO2担载量达到0.455molCO2/mol胺时,才产生HCO3-/CO32-离子。在MEA吸收CO2过程中,MEA氨基甲酸盐的摩尔分数先增加后减少。在解吸过程中,MEA氨基甲酸盐的摩尔分数同样先增加后减少。HCO3-/CO32-在解吸过程中很容易就能被解吸,而生成的MEA氨基甲酸盐中大约有75%在解吸过程中并没有被解吸。     

脱碳MEA/叔胺的性能

应用于工业烟气的CO₂吸收剂以一乙醇胺（MEA）为主,改进MEA使其成为更高效的吸收剂是吸收脱CO₂的关键之一。本文对相同浓度的MEA和3种不同结构的叔胺：即N,N-二乙基乙醇胺（DEAE）、N,N-二甲基乙醇胺（DMAE）和N-甲基二乙醇胺（MDEA）水溶液,以及MEA与这3种叔胺的混胺水溶液（MEA/叔胺）对CO₂的吸收和再生性能开展了实验研究,以期达到改进MEA性能的目的。结果表明,叔胺与MEA的吸收行为完全不同;MEA吸收性能好,叔胺再生性能强。MEA/多胺的吸收初期速率下降,但是再生量和再生率都较MEA高。叔胺与MEA在吸收和再生过程中都存在交互作用,交互作用与叔胺种类及吸收时间有关,其中MDEA与MEA之间的协同作用最强。     

用于从混合气体中吸收分离二氧化碳的溶液

本发明涉及一种用于从混合气体中吸收分离二氧化碳的溶液，为含有碳酸钾、醇胺类化合物成分、钒类化合物成分、硼酸以及多氨基或多氮类化合物成分的水溶液。其中：碳酸钾为50～250g／L，醇胺类化合物成分为5～250g／L，多氨基或多氮类化合物成分为0．5～25g／L，钒类化合物成分为6～12g／L，硼酸为0～20g／L。其中的钒类化合物成分还可以用铜类化合物成分取代。本发明的溶液尤其适用于从高含氧量并同时含有硫和氮氧化合物杂质的气体中高效率地吸收分离其中所含的二氧化碳。     

(2-羟基-3-烯丙氧基)丙基二甲基叔胺的合成研究

以二甲胺(DMA)和烯丙基缩水甘油醚(AGE)为原料合成得到(2-羟基-3-烯丙氧基)丙基二甲基叔胺(AGE-DMA),产品收率可达99. 67%。所得化合物结构经过FT-IR和1H-NMR确认。得出合成AGE-DMA的最优化条件为:n(二甲胺):n(烯丙基缩水甘油醚)=1. 00:1. 05,反应温度为50℃,反应时间为6h。该方法具有合成工艺简单、反应条件温和产率高等优点,适合工业化生产。     

两种罗汉果多糖的IR及13C NMR分析

利用FT IR和13C NMR技术对罗汉果中的两种多糖SGPS1(Siraitia grosvenorii Polysaccharides,SGPS)和SGPS2进行分析。从SGPS1和SGPS2的红外吸收(4000-500 cm-1)可知,它们具有典型的多糖吸收特征,SGPS1中的单糖残基以吡喃环和呋喃环的形式存在,SGPS2中的单糖残基以α-吡喃环的形式存在。同时运用13C NMR证实了这两种多糖的单糖残基环状构型及糖苷键构型。     

甲基丙烯酸二甲氨基乙酯-丙烯腈共聚物膜的制备及其气体渗透性能

采用水溶液沉淀法合成了甲基丙烯酸二甲氨基乙酯（DM）和丙烯腈（AN）的共聚物,用红外光谱、黏度法和X射线衍射分析了聚合物的结构.实验考察了反应条件对共聚物结构的影响.在此基础上,通过溶液浇注法制备了甲基丙烯酸二甲氨基乙酯（DM）和丙烯腈（AN）的共聚物膜,研究了聚合物膜的CO₂、CH₄渗透性能.结果表明,由于共聚物中含有能与CO₂进行可逆反应的叔胺基,共聚物膜表现出较好的CO₂渗透性和CO₂/CH₄选择性,如在25℃、压力为1140 Pa时,CO₂的渗透速率可达 3.53×10^-12 cm³(STP)•cm^-2•s^-1•Pa^-1 , CO₂/CH₄ 的理想分离因子达到104.5.利用膜吸附CO₂和CH₄后红外光谱的变化,分析了膜对CO₂的促进传递机理.     

聚异丁烯无灰清净分散剂中叔胺氮含量的测定研究

本文采用电位滴定法,对聚异丁烯型无灰清净分散剂中的叔胺氮含量进行了测定,方法简便,可靠,可满足科研和工业分析的要求。     

应用级聚苯乙烯性能的~(13)C–NMR组学特征分析

对十种牌号的工业级聚苯乙烯(PS)进行了~(13)C–NMR谱图测试并对碳谱峰的强度进行了归一化处理。通过考察材料的力学性能与组成成分之间的关系,找出了影响材料力学性能的NMR特征信息。并创新性地提出高聚物NMR组学概念。作为实例演算了一种"等区域锯齿形加和"的编码算法,得到了与材料性能有关的15段编码。编码显示,PS材料的力学性能与编码有较好的一致性,高聚物NMR组学方法具有令人期待的前景。     

A study of species formation of aqueous tertiary and hindered amines using quantitative 13C NMR spectroscopy

Tertiary and sterically hindered amines have been chosen as potential candidate absorbents, recommended for their high carbon dioxide (CO₂) loading capacity and easy regeneration. In this study, the CO₂ absorption characteristics of these amines were studied using ¹H nuclear magnetic resonance (NMR) and quantitative ¹³C NMR. The equilibrium experiments were conducted in the vapor–liquid equilibrium (VLE) apparatus, which was used to measure the CO₂ absorption capacities and relative absorption rates of aqueous solutions of methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP). The CO₂ loaded absorbents were used for NMR measurement to determine the distribution of species formed in the absorbents. This process confirmed the reaction mechanisms of the individual absorbents in relation to CO₂ absorption capacities.     

合成脂肪醇催化胺化制叔胺的反应研究

在Cu-Ni催化剂作用下利用C12-13合成醇(OXO醇)进行催化胺化反应,并与月桂醇的胺化反应进行比较,结果表明：月桂醇胺化反应3h,醇的转化率达99．9％,单烷基叔胺选择性为95．6％,OXO醇的转化率为91．3％,选择性为96．6％。胺化产物的色质分析结果表明：剩余脂肪醇全部为2-位支链的脂肪醇。OXO醇转化率不高的主要因素是所含2-位支链阻碍了脂肪醇在催化剂表面的吸附。OXO合成脂肪醇催化胺化制叔胺的主要问题是醇的转化率相对较低。     

脂肪腈加氢制备单烷基二甲基叔胺催化剂的研究

通过对催化剂活性组分的筛选,钯/碳(Pd/C)催化剂对脂肪腈与二甲胺反应制备单烷基二甲基叔胺有良好的选择性。采用浸渍-沉淀法制备出负载型Pd/C催化剂,考察了制备过程中溶液体系的pH值和浸渍时间对Pd/C催化剂性能的影响。结果表明:该溶液体系在pH值7.9和浸渍15 h~18 h的条件下得到的Pd/C催化剂对脂肪腈催化加氢制备单烷基二甲基叔胺有较好的催化性能。     

Kinetics of CO2 absorption into a novel 1‐diethylamino‐2‐propanol solvent using stopped‐flow technique

A stopped‐flow apparatus was used to measure the kinetics of carbon dioxide (CO₂) absorption into aqueous solution of 1‐diethylamino‐2‐propanol (1DEA2P) in terms of observed pseudo‐first‐order rate constant (k_o) and second‐order reaction rate constant (k₂), in this work. The experiments were conducted over a 1DEA2P concentration range of 120–751 mol/m³, and a temperature range of 298–313 K. As 1DEA2P is a tertiary amine, the base‐catalyzed hydration mechanism was, then, applied to correlate the experimental CO₂ absorption rate constants obtained from stopped‐flow apparatus. In addition, the pK_a of 1DEA2P was experimentally measured over a temperature range of 278–333 K. The Brønsted relationship between reaction rate constant (obtained from stopped‐flow apparatus) and pK_a was, then, studied. The results showed that the correlation based on the Brønsted relationship performed very well for predicting the absorption rate constant with an absolute average deviation of 5.2%, which is in an acceptable range of less than 10%. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3502–3510, 2014     

二氧化碳选择性吸收方法的研究进展

综述了二氧化碳选择性吸收方法的研究进展,包括物理吸收法、化学吸收法、膜吸收法,并分析了各种方法的优缺点。     

木质素酚醛树脂炭膜的CP/MAS 13C NMR表征

采用固体核磁共振技术CP/MAS 13C NMR分析了木质素酚醛树脂炭膜。结果显示木质素含量的变化影响到炭膜的结构,如:炭膜中侧链烷基碳、非酚型紫丁香基和羟甲基碳结构。     

Identification of Turkish extra virgin olive oils produced in different regions by using NMR (1H and 13C) and IRMS (13C/12C)

Isotope ratio mass spectroscopy (IRMS) and nuclear magnetic resonance (NMR) spectroscopy techniques are two of the analytical methods that are used to characterize food products. The aim of this study is to classify extra virgin olive oil (EVOO) samples collected from different regions of Turkey based on ¹H and ¹³C NMR spectra along with IRMS δ¹³C carbon isotope ratio data by using chemometrics multivariate data analysis methods. A total of 175 EVOO samples were analyzed in 2014/15 and 2015/16 harvest seasons. Multivariate classification and clustering models were used to identify geographical and botanical origins of the EVOOs. IRMS results showed that there was no significant difference in terms of δ¹³C values between the years in terms of harvest year (p > 0.05), only extraction phase and variety were statistically significant factors (p < 0.05). The interactions of the factors showed that the harvest year × variety interaction is important. The outcomes of this research clearly indicated that considering the partial least squares discriminant analysis result with NMR spectra, the percent success of the model in the South Marmara, North Aegean, and South Aegean region samples were 95%, 95.7%, and 96.4% in the model set, respectively. The results showed that by using classification and clustering models, geographic marking and labeling of these oils can be carried out regardless of differences in year and production systems (2 and 3 phase extraction system) according the NMR analysis.