Synthese von bipolaren Ionenaustauscherharzen

Synthesis of Bipolar Ion Exchange Resins Syntheses of weakly acid/strongly basic and weakly acid/weakly basic bipolar ion exchange resins with varying acid and basic capacities via subsequent introduction of the exchange active groups in suitable crosslinked skeletal polymers are described. Methylacrylate-styrene-divinylbenzene polymers of varying composition which can be quantitatively chloromethylated and subsequently fully aminated (trimethylamine) and partially saponified in one process step were used as starting polymers for weakly acid/strongly basic resins. The reverse route saponification of the ester groups first, followed by chloromethylation of the aromatic parts of the matrix and animation turned out to the possible, if at all, only for bipolar resins of strongly predominant basic character. The capacity parameters can be controlled through the composition of the matrix. Polymethylacrylates crosslinked with divinylbenzene served as polymer basis of the weakly acid/weakly basic bipolar ion exchange resins. The functionalization was achieved by partial aminolysis with polyamines (dimethylaminopropylamine, ethylenediamine, diethylenetriamine) and saponification with lyes. The number of basic and acid groups which can be introduced is governed primarily by the conditions of the aminolysis. The capacity parameters are controllable within a broad range by the procedures.     

聚合物改性碱式硫酸镁水泥用于路面裂缝修补的工作性能研究

为了研究聚合物改性碱式硫酸镁水泥用于路面裂缝修补的工作性能,对不同配合比的改性碱式硫酸镁水泥的粘度、可灌性、凝结时间进行了测试,讨论了不同聚合物掺量对碱式硫酸镁水泥工作性能的影响.结果表明,碱式硫酸镁水泥的粘度随着聚合物掺量的增加而减小,表现为更好的流动性和可灌性,聚合物掺量为20％时,改性碱式硫酸镁水泥对应30 min时的粘度为17 s,与未掺加聚合物的碱式硫酸镁水泥30 min时的粘度相比缩小了50％;碱式硫酸镁水泥的凝结时间随着聚合物掺量的增加先增大后减小,与未改性碱式硫酸镁水泥凝结时间相比,聚合物掺量为10％和20％时凝结时间分别延缓3 h和缩短50 min.     

碱式碳酸镁阻燃低密度聚乙烯的性能研究

采用改性剂对碱式碳酸镁进行表面改性,利用X射线衍射、偏光显微镜分析了碱式碳酸镁改性效果.并将改性的碱式碳酸镁添加到低密度聚乙烯( PE-LD)中,研究了碱式碳酸镁阻燃剂对PE-LD性能的影响.利用热重分析法分析了阻燃PE-LD的热稳定性,利用扫描电镜观察了阻燃PE-LD的微观形貌.结果表明,当阻燃剂的添加量为60%时,...     

二氧化碳酸性水溶液洗涤脱除碱性氮化合物研究

介绍碱性氮化合物对油品质量和加工过程影响，加氢精制脱碱性氮效率和存在问题，研制开发出二氧化碳酸性水溶液洗涤脱除碱性氮新技术，可将油品中碱性氮化合物分离出来，洗涤柴油脱碱氮率平均达65%以上，提高了油品安全性，本技术可以脱除碱性氮后再进行加氢精制是劣质油加工的一个新途径。此方法工艺简单，投资少，成本低。     

The effects of phenolic hydrogens and methyl substitute groups in organic dyes on their dispersion of multiple-walled carbon nanotubes

Bromocresol green (BCG) and bromophenol blue (BPB) in acidic and basic forms are used as dispersing agents to suspend multiple-walled carbon nanotubes (MWCNTs) into deionized water. The chemical structures of dye molecules are characterized by ultraviolet-visible-near infrared and nuclear magnetic resonance spectroscopic techniques. The presence of MWCNTs in water is evidenced by Raman spectra and the attachment of dye molecules to nanotubes is suggested by analysis of transmission electron microscope images. All dyes exhibit critical concentrations in dispersing MWCNTs. This may result from the formation of dye micelles, which induces osmotic pressure on MWCNTs and aids nanotube re-aggregation. The critical values of the basic dyes are lower than their acidic counterparts, which can be ascribed to the stronger hydrophilicity of basic dyes. The critical value of basic BCG is lower than basic BPB and this can be attributed to the effect of methyl substitutes in the former. Basic BCG is superior to basic BPB in stabilizing MWCNTs, which may result from the extra steric hindrance provided by the methyl substitutes.     

碱性树脂催化合成生物质五元环状碳酸酯

生物质材料环氧大豆油和CO2在碱性树脂D201的催化下,通过环加成反应生成五元环状碳酸酯。近一步对D201树脂进行改造和改性,得到系列新型碱性树脂催化剂,考察了温度、时间、催化剂种类等因素对反应的影响。结果表明,制备的碱性树脂催化剂的催化活性均高于D201树脂,其中以碘离子改进型碱性树脂催化剂的催化活性最高,在反应温度为120℃、反应时间为12 h的条件下,可使环氧大豆油的转化率达到90%以上。     

Modification of Nafion membranes by incorporation of cationic polymers for reduction of methanol permeability

A small amount of basic polymer was incorporated in the Nafion membrane. Compared with the re-cast Nafion membrane, the Nafion/basic polymer membrane reduced the methanol permeability considerably. The equilibrium water uptake and proton conductivity decreased, but the thermal and mechanical stability was enhanced with increasing concentration of basic polymer. These property changes were caused by formation of cation/anion complex between acidic Nafion and basic polymer molecules. The effects of the types and molecular weights of basic polymers on the methanol permeability and proton conductivity were not significant.     

液相色谱-串联质谱测定印染废水中3种碱性染料

建立了液相色谱-串联质谱法(LC-MS/MS)测定印染废水中碱性橙2、碱性橙21、碱性橙22三种碱性染料的检测方法。采用乙酸乙酯-环己烷混合溶液(体积比1:1)萃取碱性染料,经凝胶渗透色谱净化浓缩,液相色谱-串联质谱仪测定,结果表明:3种碱性染料在5.0~100.0 ng/m L范围内,线性关系良好,相关系数(R~2)大于0.999 6;检出限在2.5~5.0mg/L之间;回收率在88.6%~98.4%之间,相对标准偏差(RSD)在1.3%~2.7%之间。该方法自动化程度高、样品前处理简单、灵敏度高、检出限低、结果准确可靠、回收率和重现性良好,可用于印染废水中三种碱性染料残留量的同时测定。     

Urethane foams from animal fats: IX. Polyols based upon tallow and trimethylolpropane; preparation under acidic and basic catalysis

A series of polyols was prepared from epoxidized tallow, by reaction with trimethylolpropane in refluxing toluene, sequentially under basic and acidic catalysis. In preliminary experiments, under catalysis by sodium methoxide alone, the trimethylolpropane reacted rapidly with glyceride linkages and very slowly with oxirane groups. Under catalysis by p-toluenesulfonic acid alone, oxirane was rapidly consumed. Polyols were prepared by the following sequences: (A) reaction under acidic followed by basic catalysis; (B) reaction under basic followed by acidic catalysis; (C) reaction under basic catalysis followed by further treatment with HBr gas to introduce fire retardance; (D) treatment of whole tallow first with trimethylolpropane under basic conditions and secondly with bromine; (E) reaction of epoxidized tallow with diethanolamine under basic catalysis; and (F) treatment of epoxidized tallow first with trimethylolpropane under acidic conditions and then with diethanolamine under basic catalysis. The polyols described were adjusted to equivalent weights of 100 and 120 with added triisopropanolamine and treated with a polymeric isocyanate to give rigid foams. Densities ranged from 1.5–1.8 lb/ft³. Open cell content, for foams made at the equivalent wt of 100, ranged from 14–21%; at the equivalent wt of 120, from 17–27%. Compressive strengths ranged from 14–23 psi, being lower than those of the best previous epoxidized tallow-trimethylolpropane products. Presented at the AOCS Meeting, Mexico City, Mexico, May 1974. ARS, USDA.     

玻璃熔窑蓄热室系列配套优质碱性耐火材料研制及其应用

玻璃熔窑蓄热室系列配套优质碱性耐火材料研制及其应用黄渊麟，丘必云，林剑成（轻工业部玻璃搪瓷工业科学研究所２０００５２）ＤｅｖｅｌｏｐｍｅｎｔａｎｄＡｐｐｌｉｃａｔｉｏｎｏｆａＳｅｒｉｅｓｏｆＨｉｇｈ－ＤｕｔｙＢａｓｉｃＲｅｆｒａｃｔｏｒｉｅｓｆｏｒＲ...     

Comparison of concrete creep in tension and in compression: Influence of concrete age at loading and drying conditions

The relation between basic and drying creep in tension compared to basic and drying creep in compression was investigated. The results obtained can be summarized as follows. Basic creep in compression is significantly more important than basic creep in tension. This difference increases with decreasing concrete age at loading. Compression creep and tension creep are similar under drying conditions. Analysis of these results provides insight into the physical mechanism underlying basic creep in concrete: microcrack initiation generates additional strains related to the development of additional self-drying shrinkage. We thus propose that basic creep in concrete is mainly caused by additional self-drying shrinkage under stress.     

Method for the determination of surface basic groups in cationic polystyrene latexes

The method for the determination of basic groups chemically bound to the surface of particles (surface basic groups) in cationic polystyrene latexes has been investigated. It is clarified that surface basic groups such as amidino groups resulting from 2,2′-azobis(2-amidinopropane) hydrochloride used as initiator and amino groups resulting from dimethyl aminoethyl methacrylate copolymerized can be determined accurately by the following method. First, latexes are cleaned and surface basic groups are converted into unneutralized from by ion exchange; then, latexes are titrated conductometrically with strong acid. By this method, however, surface amidino groups and surface amino groups cannot be determined separately.     

Surface properties of magnesium oxide obtained from basic magnesium carbonate: Influence of preparation conditions of magnesium carbonate

Surface area, total basicity and base strength distribution (weak, strong and intermediate strength basic sites) of magnesium oxide obtained from basic magnesium carbonate (by its decomposition at 873 K) prepared by precipitation using different magnesium slats, precipitating agents and precipitating conditions (viz. concentration of magnesium salt. pH, temperature, mode of mixing and ageing period) have been thoroughly investigated. The total basicity and base strength distribution of the different magnesium oxide samples have been determined by step-wise thermal desorption of carbon dioxide from 323 to 1253 K. The chemical composition of basic magnesium carbonate and the surface properties and carbon dioxide content of magnesium oxide are found to be strongly influenced by the aforementioned preparation conditions of basic magnesium carbonate.     

碱式碳酸镁阻燃LDPE/EVA的性能研究

用硬脂酸对碱式碳酸镁进行表面改性,加入到低密度聚乙烯(LDPE)和乙烯-醋酸乙烯酯(EVA)的混合物中制备阻燃复合材料。研究了碱式碳酸镁对LDPE/EVA的阻燃及力学性能影响。用扫描电镜(SEM)和热失重(TG)分别表征阻燃复合材料的微观形貌和热性能。结果表明,碱式碳酸镁经过表面改性后,由亲水性变成了亲油性,且当加入的碱式碳酸镁份数为150份时,阻燃复合材料的拉伸强度13.1 MPa,弯曲强度5.0 MPa,冲击强度3.27 kJ/m2,断裂伸长率9.4%,氧指数31.6%。     

固体碱碱性位对3-戊酮和碳酸二甲酯反应的影响

考察了固体碱碱性位对3-戊酮和碳酸二甲酯反应的影响,并推测了反应在不同碱性位上的反应机理.实验结果表明,由表面羟基引起的弱碱位有利于3-戊酮自身缩合反应(4-甲基-5-乙基-4-庚烯-3-酮)的进行;Lewis酸碱离子对有利于碳酸二甲酯的甲基化反应的发生,主产物为2-甲基-3-戊酮和3-甲氧基-2-戊烯;而由固体碱表面...     

Sm3+掺杂碱锌硼硅酸盐玻璃析晶过程的微观结构研究

采用HTEM,NMR以及红外光谱技术,研究适宜半导体微晶掺杂的Sm3 掺杂碱硼硅酸盐基础玻璃在热处理过程中,玻璃结构的变化特点.研究结果表明,含Sm3 基础玻璃失透的主要原因在于在热作用下玻璃中[SiO4]4-以及[BO4]4-四面体结构首先分解形成了富硅相以及富硼相,稀土Sm3 则富集到富硼相中,并进一步析出了硼酸钐晶体;通过优化玻璃的组成能够改进基础玻璃的热稳定性.     

偶联剂对环氧树脂戚式碳酸镁体系力学和分散性能的影响

利用扫描电镜（SEM）和力学拉伸实验,分析和对比了硅烷、钛酸酯和铝酸酯偶联剂处理过的环氧树脂／碱式碳酸镁体系的显微结构和拉伸强度。分别研究了这些偶联剂对环氧树脂,碱式碳酸铗体系的显微结构和拉伸强度的影响。结果表明,使用硅烷偶联剂时,环氧树脂／碱式碳酸镁体系的力学性能和分散性能最好。     

Magnetic hydroxyapatite-encapsulated γ-Fe2O3 nanoparticles functionalized with basic ionic liquids for aqueous Knoevenagel condensation

Hydroxyapatite-encapsulated γ-Fe₂O₃ nanoparticles functionalized with diethyl aliphatic amine basic ionic liquids were synthesized and used as efficient magnetic catalysts for aqueous Knoevenagel condensation reactions. Quantitative conversion of the reactants was achieved under mild conditions; recycle of the catalyst, through convenient magnetic decantation, shows non-significant loss in activity. In comparison with the controlled experiments catalyzed by homogeneous basic ionic liquids and the basic ionic liquid-modified polystyrene resin, the excellent performance of the magnetic catalyst was attributed to the cooperativity between the base sites generated by framework HAP and the supported basic ionic liquids.     

改性碱式氯化镁晶须/丁苯橡胶复合材料制备与性能研究

以工业活性轻烧氧化镁粉和盐酸为原料,采用水溶液法制备了碱式氯化镁晶须,继而采用硅烷偶联剂对碱式氯化镁晶须进行改性,然后将其与丁苯橡胶混炼得到改性碱式氯化镁晶须/丁苯橡胶复合材料,研究了改性碱式氯化镁晶须对丁苯橡胶力学性能及热学性能的影响。结果表明：采用水溶液法制备得到的碱式氯化镁晶须结构为Mg₂（OH）₃Cl·4H₂O,呈微细纤维状,分布较均匀,长径比大于20;改性碱式氯化镁晶须的加入,可以改善丁苯橡胶的机械强度和阻燃性能。     

基于一维数值分析的FRP筋基本锚固长度研究

采用一维数值分析程序,对12组拉拔模型试验数据进行模拟计算,得到FRP筋的基本锚固长度,分析基本锚固长度以内界面粘结强度分布情况随拉拔应力增加时的演化,表明基本锚固长度受残余界面强度的影响很大。建立考虑极限粘结强度、残余粘结强度、直径、屈服强度等影响因素的新的FRP筋基本锚固长度的计算公式,新公式简化了计算程序,对计算结果拟合精度良好。