月桂酸酯季铵盐阳离子表面活性剂的合成与表征

以十二烷基二甲基叔胺、环氧氯丙烷为原料,合成了中间体DMAC〔(2,3-环氧丙基)十二烷基二甲基氯化铵〕,再与月桂酸反应,生成月桂酸酯季铵盐阳离子表面活性剂HDAC〔(2-羟基-3-月桂酰氧基丙基)十二烷基二甲基氯化铵〕。通过正交实验确定了最佳合成条件:以异丙醇为溶剂,n(DMAC)∶n(LAC)=1∶1.2,反应时间6 h,反应温度50℃,产率大于90%,Krafft点-4.52℃。通过元素分析、傅立叶变换红外光谱、飞行时间质谱(TOF-MS)、1HNMR,确证了目的产物的结构。测定产物的临界胶束浓度CMC为8.91×10-4mol/L,γCMC为34.12 mN/m。表明所合成的月桂酸酯季铵盐阳离子表面活性剂具有较高的表面活性。     

糖苷基季铵盐表面活性剂的合成及表面性能研究

以葡萄糖和3-氯-1,2-丙二醇为原料合成中间体3-氯-2-羟丙基糖苷,在Na OH碱性条件下与十二/十四烷基二甲基叔胺反应合成糖苷基季铵盐,通过单因素试验确定了最佳工艺。对于糖苷化反应∶n(葡萄糖)∶n(3-氯-1,2-丙二醇)=1∶4,反应时间5 h,反应温度95℃;对于季铵化工艺:n(3-氯-2-羟丙基糖苷)∶n(十二/十四烷基二甲基叔胺)=1.3∶1,反应温度90℃,反应时间4 h。通过傅里叶变换红外(FT-IR)光谱表征产物结构,测定最终产物的表面性能,能得到活性剂的临界胶束浓度(CMC)为1.68×10-3mol/L,最低表面张力(γCMC)为27.6 m N/m。     

柠檬酸三酯三季铵盐阳离子表面活性剂的合成

采用柠檬酸、环氧氯丙烷和十二烷基二甲基叔胺合成三烷基三季铵盐阳离子表面活性剂。得到较佳工艺条件:n(柠檬酸)∶n(十二烷基二甲基叔胺)∶n(环氧氯丙烷)为1∶3∶3,于85℃下反应12 h,得到产率大于90%的目的产物。测定了产物的cmc为3.3×10-4mol/L。研究了反应条件对目的产物产率的影响。结果表明:随反应温度的升高,产率逐渐增加,当升温到一定程度后,产率略有下降;反应12 h后产率基本不再变;十二烷基二甲基叔胺及环氧氯丙烷与柠檬酸的投料比大于3时,对三烷基三季铵盐阳离子表面活性剂产率的增加影响不大;异丙醇溶剂有利于反应产率的提高,但随着溶剂量的增多,反应产率会下降。     

木质素磺酸季铵盐两性表面活性剂的合成和性能

针对木质素利用率低造成环境污染与资源浪费问题,以木质素磺酸钠为原料制备木质素磺酸季铵盐两性表面活性剂,对合成工艺和产品性能进行系统研究,以期为木质素的变废为宝提供参考。结果表明,最优的合成条件为:n(木质素磺酸钠)∶n(环氧丙基十二烷基二甲基氯化铵)=1∶1.1、反应时间2.5 h、反应温度50℃、pH 12,影响反应的主要因素是pH值,其次是物质的量比、反应时间和温度,产物活性物质含量为51.8%。红外光谱和紫外光谱分析表明反应后在酚羟基中引入了烃基。产物具有较低的表面张力、较强的分散力和发泡性能,在酸性和碱性溶液中溶解性良好、亲水性较强、乳化性能一般,在洗涤剂等方面具有应用潜力。     

菊粉季铵盐的合成及性能

该文用菊粉、环氧氯丙烷和十二烷基二甲基叔胺为原料合成了一种菊粉季铵盐表面活性剂。考察了原料摩尔比、催化剂用量、反应温度和反应时间对菊粉季铵盐取代度的影响。最佳反应条件为:n(菊粉)∶n(环氧氯丙烷)∶n(十二烷基二甲基叔胺)=1∶3∶3,催化剂硫酸0.6mL(质量分数26%),70℃反应7h,取代度最高达到1.33。该菊粉季铵盐的CMC=2.78×10-4mol/L,γCMC=29.27mN/m,临界溶解温度Krafft点<0℃,质量浓度3g/L时乳化时间为30min,浓度0.01mol/L时的增溶能力为680mL/mol。与其他生物质资源的阳离子衍生物相比,该菊粉季铵盐具有更强的降低表面张力的能力。     

含酯基不对称双季铵盐表面活性剂的合成

以长链烷基叔胺、盐酸、环氧氯丙烷为原料,合成了N (3 氯 2 羟丙基) N,N 二甲基长链烷基氯化铵,研究了其合成工艺,优化反应条件为:n(长链烷基叔胺)∶n(盐酸)∶n(环氧氯丙烷)=1∶1∶1 1,反应温度为40℃,体系pH=6～7。以月桂酸及2 二甲氨基乙醇为原料,酯化得到二甲基月桂酸乙基叔胺(Ⅲ),利用其与N (3 氯 2 羟丙基) N,N 二甲基长链烷基氯化铵季铵化得到含酯基不对称双季铵盐阳离子表面活性剂〔长链烷基分别为(Ⅰ)C12H25和(Ⅱ)C14H29〕。经测定,产物的临界胶束浓度CMC分别为6 61×10-3、8 31×10-3mol·L-1,γCMC分别为37 6、39 2mN·m-1,证明所合成的含酯基不对称双季铵盐阳离子表面活性剂具有较高的表面活性。     

一种季铵盐阳离子表面活性剂的合成与性质

以氯丙烯与N,N-二甲基十二烷基胺(DTA)为原料合成了季铵盐阳离子表面活性剂十二烷基二甲基烯丙基氯化铵(DADAC);研究了原料配比、反应温度、反应时间和溶剂等因素对生成物DADAC收率的影响,通过红外光谱、元素分析确定其化学结构。较佳反应条件为:n(氯丙烯)∶n(DTA)=3∶1,无水乙醇为溶剂,50℃下反应24 h,DADAC收率为93.76%。最后测定了产物的表面性能,得到25℃下,DADAC的cmc为5.76 mmol/L,在cmc时的γ=34.2 mN/m,Krafft点<0℃。     

含酰胺键表面活性剂的合成及其性能

以苯胺、对甲氧基苯胺和氯乙酰氯为原料,通过酰胺化反应合成了氯乙酰苯胺(中间体A)和4-甲氧基-N-氯乙酰苯胺(中间体B)。中间体A和B再分别与N,N-二甲基癸胺、N,N-二甲基十二胺、N,N-二甲基十四胺通过季铵化反应,合成烷基二甲基-2-苯胺基甲酰甲基氯化铵(系列Ⅰ)和烷基二甲基-2-(4-甲氧基)苯胺基甲酰甲基氯化铵(系列Ⅱ)表面活性剂。利用1HNMR、IR和MS对产物及中间体的结构进行表征。分别测定了合成表面活性剂在298.15、308.15、318.15 K的临界胶束浓度(CMC),进行热力学参数计算。测定了298.15 K时合成表面活性剂的表面张力γ、起泡性、稳泡性和乳化能力。结果显示:由电导率法测得的Ⅱ14的CMC值最小,为0.50 mmol/L,Ⅰ10的γCMC值最小,为32.50 m N/m,Ⅰ14和Ⅱ14稳泡性最好为100%,Ⅰ12的乳化时间最长为1602 s。相同条件下,传统表面活性剂十二烷基二甲基苄基氯化铵(BAC-12)的CMC值为9.51 mmol/L,γCMC值为38 m N/m,稳泡性为44%,乳化时间为366 s。     

四聚季铵盐表面活性剂的合成及性能评价

采用乙二胺,环氧氯丙烷,N,N—二甲基十二烷基叔胺,N,N—二甲基十四烷基叔胺,N,N—二甲基十六烷基叔胺等试剂作为原料,合成了四聚季铵盐型表面活性剂。研究了三种合成产物的表面活性和其在石英片上的润湿性。实验结果表明三种合成的表面活性剂都有具有较低的临界胶束浓度(CMC值),且使用十四烷基叔胺作为合成原料的产物,具有最好性能。     

季铵盐双子表面活性剂N,N’-双（十二/十四烷基二甲基）-1,4-对苯二甲基氯化铵盐的合成及性能

分别以十二烷基二甲基叔胺、十四烷基二甲基叔胺和对二氯苄(XDC)为原料,"一步法"合成了两种季铵盐双子表面活性剂,通过正交实验优化了合成条件,结果表明,当n(叔胺)∶n(XDC)=2.4∶1、反应温度75℃、反应时间2 h时,XDC转化率达到100%;产物结构经红外光谱(FTIR)、核磁共振氢谱(1HNMR)和碳谱(13CNMR)进行了确认。研究了其表面活性,结果表明:25℃时,碳链长度分别为12和14时,表面活性剂临界胶束浓度(CMC)分别为1.36×10-5和2.56×10~(-6)mol/L,表面张力(γCMC)分别为40.71和35.37 m N/m;p C20值分别为5.63和6.18;表面过剩吸附量(Γmax)分别为2.41×10~(-6)和3.09×10~(-6)mol/m~2;分子最小截面积(Amin)分别为0.69和0.54 nm~2。动态表面张力参数n值分别为0.85、0.74,t*分别为1.05和0.27 s,R1/2分别为14.11和69.79 m N/m/s,R=14的双子表面活性剂的动态表面张力优于R=12时。该季铵盐双子表面活性剂与结构相似的季铵盐表面活性剂如十六烷基三甲基溴化铵(CTAB)相比CMC低2个数量级。     

Adsorption of phenol onto activated carbons having different textural and surface properties

Adsorption of phenol in aqueous phase onto activated carbons (ACs) having different textural and surface properties has been considered. Six types of ACs were used: three were commercial, and three were obtained from Kraft lignin chemically activated with sodium hydroxide, potassium hydroxide or ortho-phosphoric acid. The apparent surface areas of the commercial ACs varied from 620 to 1320 m²/g, while ACs made from lignin presented surface areas as high as 1300 m²/g and 2900 m²/g when prepared with H₃PO₄ and alkaline hydroxides, respectively; moreover, the highest proportion of microporosity was found for ACs derived from lignin. A kinetic study was carried out, showing that the phenol adsorption data may be correctly adjusted, for all the ACs tested, by an equation corresponding to a pseudo second-order chemical reaction. Freundlich, Langmuir and Tempkin equations were tested for modelling the adsorption isotherms at equilibrium, and it was concluded that Langmuir model fitted adequately the experimental data. However, Tempkin model fitted even better the adsorption data obtained with ACs derived from lignin activated with alkaline hydroxides, which are characterized by the highest number of surface groups. Remarkably high phenol adsorption capacities were found for the ACs prepared by activation of Kraft lignin with NaOH and KOH: 238 and 213 mg/g of AC, respectively. Finally, the adsorption of phenol was found to depend not only on the micropore volume, but also on the total amount of carbonyl and basic groups and on the ratio of acid to basic groups.     

Study on the catalytic degradation of sodium lignosulfonate to aromatic aldehydes over nano-CuO: Process optimization and reaction kinetics

As one of the few renewable aromatic resources, the research of depolymerization of lignin into high-value chemicals has attracted extensive attention in recent years. Catalytic wet aerobic oxidation (CWAO) is an effective technology to convert lignin like sodium lignosulfonate (SL), a lignin derivative, into aromatic aldehydes such as vanillin and syringaldehyde. However, how to improve the yield of aromatic aldehyde and conversion efficiency is still a challenge, and many operating conditions that significantly affect the yield of these aromatic compounds have rarely been investigated systematically. In this work, we adopted the stirred tank reactor (STR) for the CWAO process with nano-CuO as catalyst to achieve the conversion of SL into vanillin and syringaldehyde. The effect of operating conditions including reaction time, oxygen partial pressure, reaction temperature, SL concentration, rotational speed, catalyst amount, and NaOH concentration on the yield of single phenolic compound was systematically investigated. The results revealed that all these operating conditions exhibit a significant effect on the aromatic aldehyde yield. Therefore, they should be regulated in an optimal value to obtain high yield of these aldehydes. More importantly, the reaction kinetics of the lignin oxidation was explored. This work could provide basic data for the optimization and design of industrial operation of lignin oxidation.     

混合溶剂对TiO2/PVDF平板超滤膜性能和结构的影响

采用N,N-二甲基乙酰胺(DMAC)和N-甲基吡咯烷酮(NMP)为混合溶剂制备PVDF超滤膜。考察了不同混合比例的DMAC和NMP对膜性能及膜结构的影响,同时利用扫描电子显微镜(SEM)对膜表面及断面结构进行分析,原子力学显微镜(AFM)对膜表面粗糙度进行了分析,利用接触角测量仪对膜表面接触角进行了测量。结果表明,使用混合溶剂对膜孔径和膜亚层结构影响较大,但混合溶剂对膜孔隙率和接触角基本没有影响。当混合溶剂DMAC/NMP为1:2时,膜性能达到最优,孔隙率为70%,平均孔径为0.24μm,水通量为373 L.m-2.h-1,截留率为88%。     

戊二醛交联碱木质素/聚乙烯醇膜的制备及其光学性能

以碱木质素和聚乙烯醇(PVA)为原料,以戊二醛为交联剂利用流延法制备了碱木质素/PVA交联反应膜。通过单因素实验考查了碱木质素加入量、戊二醛加入量对木质素／PVA反应膜光学性能的影响。采用SEM和FT-IR方法分析反应膜的表面形貌和化学结构,紫外可见光谱法分析了交联膜的光学性能。结果表明:当碱木质素和聚乙烯醇质量比为1∶10,戊二醛加入量 1.67 %,薄膜的透光率和吸光度都较好。碱木质素/PVA薄膜结构中有醚键生成,碱木质素和PVA发生了交联反应;碱木质素/PVA反应薄膜表面较光滑;加入碱木质素后,薄膜在紫外光区的吸光度提高了近 90 %,在可见光区的透过率降低了近 40 %,碱木质素对薄膜的吸光度和透过率影响较大;戊二醛的加入量增多可见光区透过率有所增大,但戊二醛对薄膜在紫外区吸光度变化不大,薄膜的紫外线吸收主要是受碱木质素的影响。碱木质素/PVA反应膜可作为良好的紫外吸收材料。     

木质素阳离子乳化剂的制备及其表面活性

先用环氧氯丙烷和三乙胺反应制备环氧丙基三乙基氯化铵中间体,再与木质素反应制得木质素季铵盐。中间体制备条件是温度45～50℃,时间3h,n(三乙胺)/n(环氧氯丙烷)=1～1 1。木质素季铵盐制备条件为温度50～55℃,时间2h,n(木质素)/n(中间体)=0 6～0 8,pH>10 5。产物的表面活性测定表明,不同接枝率的木质素季铵盐降低水溶液表面张力的能力相差不大,最低表面张力约为40mN/m。     

Syntheses and properties of PI/clay hybrids

A new organomontmorillonite (CM) for PI hybrids has been developed by ion‐exchange reaction of cetyl pyridum chloride with Na⁺ montmorillonite (MMT). Polyimide/clay hybrids have been synthesized by employing two methods. Method I is by first blending a dimethylacetamide (DMAC) solution of 4,4′‐oxydianiline diamine (ODA) with a DMAC dispersion of CM before adding pyromellitic dianhydride (PMDA). Method II is by blending a DMAC solution of poly(amic acid) with a DMAC dispersion of CM. Tensile, thermal, dielectric, and water‐absorption properties of hybrids prepared by these two methods have been studied in detail. Results show that these properties depend on the clay type (organophilic or not), clay concentration, and the method to synthesis hybrids. The CM concentration of 3 wt % in the hybrid by Method II results in optimum properties in tensile strength, modulus, elongation, coefficient of thermal expansion (CTE), and water absorption. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1902–1910, 2001     

IRS study of ethylene polymerization catalyst SiO2/MAO/zirconocene

Summary Lewis acidic sites (LAS) of silica, modified with TMA and MAO samples differed by TMA content, have been characterized by IR spectroscopy (CO adsorption as probe molecule at 77 K). Two types of LAS were found on the surface of silica modified with MAO and TMA: M LAS of moderate strength (ν_CO= 2204−2212 cm⁻¹) and weak W LAS (ν_CO= 2194 cm⁻¹). The concentration of these acidic sites has been estimated. It was shown by IRS study Cp₂ZrMe₂ interacts both with W LAS and M LAS. Correlation between the amount of M LAS and the activity of ethylene polymerization has been found. Received: 13 October 1998/Revised version: 10 June 1999/Accepted: 10 June 1999     

含氮硼酸酯表面活性剂的合成及表面活性

以月桂酸、N-(2-羟乙基)乙二胺、硼酸和二乙醇胺为原料,合成了咪唑啉硼酸酯(简称IBE)和咪唑啉醇胺硼酸酯(简称IBE-A),比较了两种硼酸酯的抗水解、表面张力等性能,考察了IBE-A与十二烷基苯磺酸钠(LAS)复配的协同效应。结果表明,氮原子的引入有效地增强了硼酸酯抗水解性能,其中IBE-A具有很好的抗水解性能;随pH增加,IBE和IBE-A临界胶束浓度(CMC)和γCMC下降;在中性及碱性条件下,IBE-A的CMC=(1.20~1.35)×10-3mol.L-1,γCMC=(31.1~31.4)mN.m-1。IBE-A和LAS有较强的复配协同效应,当n(IBE-A)∶n(LAS)=4∶6时,CMC=3.16×10-5mol.L-1,γCMC=29.6 mN.m-1,其中CMC分别是IBE-A水溶液CMC(1.35×10-3mol.L-1)和LAS水溶液CMC(1.14×10-3mol.L-1)的1/43和1/36。     

Side reactions of phenylisocyanate in N,N-dimethylacetamide

Side reactions of isocyanate groups in N,N-dimethylacetamide (DMAC) were studied. Although 4,4′-diphenylmethane diisocyanate (MDI) in DMAC was stable and no changes occurred at 3°C, the isocyanate content decreased and a gel was finally formed at 40°C. Using phenyl isocyanate (PI) as a model compound of MDI, the identification of PI side-reaction products in DMAC were studied. From these experiments, the following five products were identified; (1) 1,3-diphenylurea (DPU), (2) 1,3-diphenyl-5-phenylcarbamyl-6-dimethylaminouracil (PUR), (3) 1,3,5-triphenylbiuret (TPB), (4) triphenyl-s-triazine-2,4,6-trione (TTT), and (5) 1,1-dimethyl-3-phenylurea (DMPU). Among these identified products, the novel side reaction product PUR, which was formed between PI and DMAC as solvent, was found along with TPB and TTT, which were already known to cause three-dimensional network formation.