水热一步法合成SO2-4/Zr-PHTS及其催化性能

在低酸度硫酸体系中,以P123 (EO20PO70EO20)为模板剂水热法一步合成硫酸化锆掺杂PHTS固体酸催化剂(SO2-4/Zr-PHTS),利用XRD、TEM、N2吸附脱附以及NH3-TPD、Py-FTIR等手段对其进行表征.结果表明,SO2-4/Zr-PHTS具有有序的六方相介孔结构,具有以L酸为主的弱、中强度的酸性中心;随着硅锆摩尔比的增加,其酸量逐渐减少,比表面积逐渐增加,孔容、孔径无显著变化.SO2-4/Zr-PHTS在催化四氢呋喃聚合中表现出良好的反应性能,推测固体酸的表面酸性和孔结构决定着催化四氢呋喃聚合的反应性能.     

水热一步法合成SO42-/Zr-PHTS及其催化性能

在低酸度硫酸体系中,以P123(EO₂₀PO₇₀EO₂₀)为模板剂水热法一步合成硫酸化锆掺杂PHTS固体酸催化剂(SO₄^2-/Zr-PHTS),利用XRD、TEM、N₂吸附-脱附以及NH₃-TPD、Py-FTIR等手段对其进行表征。结果表明,SO₄^2-/Zr-PHTS具有有序的六方相介孔结构,具有以L酸为主的弱、中强度的酸性中心;随着硅锆摩尔比的增加,其酸量逐渐减少,比表面积逐渐增加,孔容、孔径无显著变化。SO₄^2-/Zr-PHTS在催化四氢呋喃聚合中表现出良好的反应性能,推测固体酸的表面酸性和孔结构决定着催化四氢呋喃聚合的反应性能。     

杂多酸-乙酐催化四氢呋喃聚合的反应机理

研究了体系中存在乙酐时,四氢呋喃在杂多酸催化下进行阳离子开环聚合的反应机理。结果表明,杂多酸—乙酐络合物有较高的引发活性,该反应在笼型结构（四氢呋喃与杂多酸络合形成）中的杂多酸表面进行,经历了四氢呋喃与杂多酸络合、乙酐与杂多酸络合引发、四氢呋喃开环聚合及链终止反应等阶段,建立了以笼型结构为中心的机理模型。     

星形中乙烯基聚丁二烯橡胶的合成与表征

以多官能团有机锂为引发剂，四氢呋喃为微观结构调节剂，在抽余油中一步法合成了星形中乙烯基聚丁二烯橡胶（S-MVBR），并对其结构进行了表征。结果表明，在2L聚合釜中，聚合单体质量浓度为0.08-0.09g/mL,50℃下反应2h后，再在80℃下反应1.5-2h；通过调节四氢呋喃用量和改变温度可调节S-MVBR中的1，2-结构质量分数为35%-55%；通过调节多官能团有机锂引发剂所含的活性中心数及繁臂的相对分子质量来控制S-MVBR的相对分子质量；通过多官能团有机锂引发剂的官能团分布来调节S-MVBR的相对分子质量分布；S-MVBR中的凝胶质量分数小于1%。     

磷钨钒杂多酸的制备、表征及催化合成四氢呋喃

通过水热法制备了系列Keggin结构磷钨钒杂多酸催化剂,并通过FT-IR、UV-Vis对催化剂结构进行表征.以1,4-丁二醇脱水合成四氢呋喃为探针反应,考察催化剂催化性能.通过正交实验确定了反应的优化条件:钒原子取代个数为3,催化剂质量分数为3.93％(相对1,4-丁二醇质量),反应温度180 ～ 190℃,反应时间50 min,四氢呋喃平均收率达85.4％.催化剂重复使用3次,收率仍可达82.3％.本工艺具有绿色、安全、操作简单等优点.     

四氢呋喃的阳离子开环聚合

本文介绍了在乙酸酐—高氯酸催化下四氢呋喃开环聚合制备端羟基聚四氢呋喃反应的研究。探讨了催化剂组成和用量对聚合物分子量的影响。并用ＦＴ—ＩＲ、’ＨＮＭＲ对聚合物的结构进行了表征。     

Y型分子筛催化剂的表面酸性及催化性能的研究

利用吡啶吸附红外光谱(Py-IR)和X-射线衍射法表征了磷钨酸(PW)、氢氧化铌改性分子筛的表面酸性和结构,用催化法脱除芳烃中微量烯烃的烷基化反应研究其酸催化性质。结果表明,催化剂的结构、表面酸含量和磷钨酸、氢氧化铌在催化剂中所占的比例,都显著地影响烷基化反应;Dawson结构的磷钨酸比Kiggen结构的磷钨酸具有较好的催化烷基化反应活性;随着磷钨酸含量的增加,催化剂B酸量先增加后减少,L酸量减少;随着氢氧化铌含量的增加,总B酸量和L酸量都减少,催化剂的活性随总B酸量与总L酸量比值的增加而提高;用磷酸或草酸处理氢氧化铌,总B酸量与总L酸量的比值增大,可进一步提高分子筛的活性和寿命。研究结果还表明,强B酸不利于脱烯烃反应。     

H2O2处理对HZSM-5分子筛结构及催化环己烯水合性能的影响

利用H2O2对HZSM-5分子筛进行处理,并采用X射线衍射、N2低温吸附、扫描电子显微镜、NH3-TPD和吡啶吸附-脱附红外光谱等方法进行表征.考察H2O2处理对HZSM -5结构以及催化环己烯水合反应活性的影响.结果表明,处理后分子筛的颗粒变小,颗粒尺寸(0.5～0.7) μm,酸量下降,L酸中心数减少,B酸增强.H...     

钼基开环移位催化剂催化双环戊二烯聚合研究

分别用对甲基苯酚、壬基酚、2,6-二叔丁基-4-甲基苯酚、2,4,6-三溴苯酚和2,4-二硝基苯酚与五氯化钼(MoCl5)反应,制备出系列用于双环戊二烯(DCPD)开环移位聚合的钼-酚催化剂。考察了不同结构催化剂的活性及其在不同条件下对催化DCPD开环聚合的影响。以红外光谱和示差扫描量热分析表征了聚合产物的结构和性能。结果表明,产物中钼-对甲基苯酚的活性最高,其催化DCPD聚合的单体转化率为98.07%,交联度为90.44%。同时发现钼-酚催化剂催化DCPD聚合的凝胶时间随着Mo、Et2AlCl物质的量的增加和温度的升高而减小,而单体转化率和交联度则先增大后减小。     

SnO2掺杂对SO42-/TiO2固体酸催化剂酯化反应活性的影响

采用共沉淀与浸渍法制备了一系列不同SnO2掺杂量（1%-7%,摩尔分数）SO42-/TiO2-SnO2固体酸催化剂,利用N2-吸附脱附分析、FT-IR、XPS、NH3-TPD等手段对催化剂的结构和性质进行了表征,结果表明： SnO2掺杂可以有效改善催化剂的比表面积与孔道结构,有利于与SO42-形成配位结构,显著增加了催化剂酸性中心数量,从而增强了催化性能。SnO2掺杂量为5%的SO42-/TiO2-SnO2固体酸催催化丙烯酸与莰烯酯化反应中,莰烯的转化率为77.3%,丙烯酸异冰片酯选择性98.4%,较于SO42-/TiO2,显示出更高的反应活性与稳定性。     

Mechanism of palm oil bleaching by montmorillonite clay activated at various acid concentrations

The mechanism of bleaching by a nonswelling montmorillonite clay activated at various acid concentrations was studied in the bleaching of palm oil. Montmorillonite clay was activated by 2 parts of H₂SO₄ at concentrations of 10-40%. Chemical composition, bleaching ability, specific surface area and phosphorus content were studied. The study showed that an initial increase in bleaching ability by clay activated by an increasing addition of H₂SO₄ was due to acid leaching of organic matter and impurities in the clay. The consequence of acid leaching in this case tends to expose active sites for adsorption. Acid leaching also removed Al³⁺, causing charge deficiency in the clay lattice and, hence, promoting the adsorption properties of the clay. A drop in bleaching efficiency at higher additions of H₂SO₄ was observed. This was due to exces-sive acid leaching of Al³⁺, causing collapse of the clay lattice struc-ture.     

硝酸改性凹凸棒石粘土及吸附Cu2+的工艺研究

将凹凸棒石粘土用硝酸进行改性处理,然后用于对含铜废水中铜离子的吸附,研究了硝酸浓度、改性凹凸棒石粘土用量、吸附时间、pH值等因素对吸附性能的影响。结果表明:经4mol/LHNO3改性处理后的凹凸棒石粘土吸附能力最好,凹凸棒石粘土加入量为30g/L,水样pH值为4,超声搅拌20min,废水中Cu2+的吸附率接近99%,同时吸附剂的再生实验表明,复用时吸附量下降平缓,可以重复使用。     

Mechanical properties of gamma‐irradiated styrene‐butadiene rubber/acid‐treated vermiculite clay/maleic anhydride nanocomposites

Nanoparticle vermiculite (VMT) clay was prepared by treatment with hydrochloric acid. Styrene‐butadiene rubber (SBR) nanocomposites were prepared by mixing different contents (2.5, 5, 7.5, and 10 phr) of untreated (VMT) and acid‐treated (DVMT) vermiculite clay, respectively. In addition, different contents (3, 7, and 10 phr) of maleic anhydride (MA) as compatibilizer were mixed via direct melt compounding in internal mixer. The effect of gamma irradiation, VMT clay, and MA contents on the mechanical properties was studied. The acid‐treated VMT clay was characterized by x‐ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FT‐IR) spectroscopy. Meanwhile, the SBR/VMT composites, SBR/DVMT, and SBR/DVMT/MA nanocomposites were characterized via crosslinking density and tensile mechanical testing and FT‐IR spectroscopic analysis. The results indicated that good yield of nanoparticle vermiculite was achieved when the acid treatment was carried out for 120 h. In addition, the results showed that the presence of DVMT clay improved the chemical bonding in the SBR nanocomposites and hence their mechanical properties. The highest improvement was obtained when the contents of DVMT clay, MA, and irradiation dose were 10 phr, 3 phr, and 100 kGy, respectively. POLYM. ENG. SCI., 59:355–364, 2019. © 2018 Society of Plastics Engineers     

Catalytic activity of acid-treated montmorillonite in polar and non-polar reaction media

The catalytic activity of acid-treated montmorillonite clay towards Brønsted acid catalysed reactions is shown to be highly dependent on the degree of acid treatment received by the clay. Using two contrasting model reactions, one involving highly polar reactants and the other a non-polar reactant, the optimum treatment conditions for an acid-treated clay catalyst are also shown to depend upon the type of reaction being catalysed. In addition, the role of exchangeable Al³⁺ ions in generating catalytically active acid sites in the two reactions is investigated.     

Adsorption studies of fatty acids on montmorillonite‐based filler clay

Surface coating of montmorillonite‐based filler clay with stearic and oleic (9‐octadecenoic acid) acids was presented. Sedimentation measurements showed that the sedimentation rate and the sediment volume decreased sharply with the adsorbed amount of the acid up to a certain concentration and then became constant. The chemical analysis showed that the adsorbed amount of either acid by montmorillonite clay increased with the equilibrium concentration of the acid in the solution. The adsorption isotherm indicated the formation of a monolayer on the clay surface at a lower concentration of the acids followed by formation of multilayers of the acids on the clay surfaces at higher concentrations. XRD analysis indicated no intercalation of either acid in the lamella of the clay. We concluded the possibility of surface coating of montmorillonite clay with a monolayer of fatty acids that render the clay organophilic. The adsorption of either acid improved the dispersibility of the clay particles in organic or polymeric media. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2574–2580, 2002     

工业级塔拉单宁酸的制备研究

探讨了工业级塔拉单宁酸的提取及纯化工艺,并由正交试验确定了最优提取条件:提取时间3 h,提取温度50℃,料液比1∶15 g/mL,提取次数3次;硅藻土、活性白土和活性炭最佳添加量均为1.5%,塔拉单宁酸质量分数可达到80%以上。     

Selective Catalytic Reduction of NO by NH3 on Sulfated Titanium-Pillared Clay

Structural, textural and surface properties of sulfated and non-sulfated titanium-pillared clay were correlated with catalytic tests in the reduction of NO by NH₃ in the presence of oxygen. Lower specific surface areas and basal spacings but stronger acid sites were observed on sulfated Ti-pillared clay than on Ti-pillared clay. Sulfated Ti-pillared clays were more active than Ti-pillared clay. Accordingly, it is suggested that the strong Brønsted acidity generated by sulfate is responsible for the high reactivity of sulfated Ti-pillared clay at high temperature.     

Thermal alteration of oleic acid in the presence of clay catalysts with co-catalysts

The effects of added co-catalysts on the clay catalyzed polymerization of oleic acid have been investigated. Heating oleic acid at 230 C for 3 hr with a clay catalyst gave a polymer fraction (dimer and trimer acids, 35% yield) and a monomer fraction (branched chain isomers of oleic acid, 27% yield) as the major products. The variation in yield between the polymer and monomer products was found to be dependent upon the co-catalyst used with the clay catalyst. For example, with both acidic and basic clays, polymer formation is favored (55% yield) in the presence of water and/or metal ions. In contrast, when Bronsted acids such as methanesulfonic or phosphoric acid are used as co-catalysts, the yield of branched monomer increased significantly (50%). Studies on the adsorption of oleic and Bronsted acids onto the clay surface showed that isomer formation is favored when both the oleic acid and the Bronsted acids are adsorbed onto the clay surface at selected molar ratios.     

固体酸催化合成2-乙酰噻吩

制备了磷酸/活性白土、FeCl3/活性白土、Fe(III)树脂、SO42-/Fe2O3等固体酸催化剂,并考察了其对噻吩与乙酸酐反应合成2-乙酰噻吩的催化性能。结果表明,磷酸/活性白土的催化效果较好。在适宜的反应条件下,以磷酸/活性白土为催化剂,合成2-乙酰噻吩的收率达到90%,选择性高于99%。催化剂重复使用4次后,活性有一定的下降。     

改性高岭土性能的研究

采用N2吸附、IR酸性表征和SEM等手段研究碱改性或酸改性高岭土的孔体积、比表面积、酸性及形貌特征。采用改性后高岭土部分替代高岭土制备FCC催化剂,并利用ACE对制备的3种催化剂进行性能评价对比。结果表明,高岭土经过酸碱改性后,碱改性高岭土的孔体积为0.30 mL·g-1,比表面积为111 m2·g-1;酸改性高岭土的孔体积为0.27 mL·g-1,比表面积为146 m2·g-1,孔体积和比表面积均有大幅提高,表现出一定的L酸酸性。改性后高岭土部分替代高岭土制备的FCC催化剂抗重金属污染能力较强,重油转化能力提高,碱改性高岭土制备的催化剂活性更高,但焦炭产率较高。