聚羧酸系高效减水剂减水机理研究

重点叙述了聚羧酸高效减水剂的特点、研究和发展的状况,并就聚羧酸减水剂的减水机理、分子结构对减水率的影响、减水剂在水泥中的化学作用等因素进行了较详细的综述,分析了影响减水率的规律和可能的作用机理。     

甲基萘磺酸系高效减水剂合成研究

减水剂在建筑混凝土中应用广泛,其中萘系高效减水剂具有减水率高,对混凝土的强度不产生有害影响且成本低的优点,在市场上占80%,其它各种减水剂由于减水率低的缺点在市场上仅占20%。实验以甲基萘油为原料,经过磺化、水解、缩合、中和四步反应,合成减水率高达16.8%的甲基萘磺酸系高效减水剂,并对合成中滴加硫酸温度、磺化温度、水解加水量、甲基萘与甲醛的物质量比等的各种影响因素作了进一步的探讨。     

磺化聚乙烯中空纤维膜渗透蒸发分离水／乙二醇混合物的研究

采用异相氯磺化的方法，使聚乙烯（ＰＥ）中空纤维膜进行氯磺化反应，并将反应产物进一步水解和离子交换，可获得具有离子交换功能的磺化聚乙烯（ＳＰＥ）中空纤维离子交换膜。应用渗透蒸发膜分离方法，研究磺化聚乙烯中空纤维离子交换膜对水／乙二醇混合物的分离效果。讨论了反离子的种类、渗透蒸发分离温度和水／乙二醇混合液的组成等对磺化聚乙烯中空纤维离子交换膜的分离效果的影响。     

双酚A的缩合及磺甲基化过程研究

磺化在有机合成中的一个重要作用是赋予主体化合物的水溶性。磺甲基化聚合物有很好的耐热稳定性,已广泛应用于油田、建材、医疗、制革等行业。本文通过对双酚A的磺甲基化反应过程中产物的分析研究,导出反应过程变化规律,研究清洁化制革用白色鞣剂的制备方法。     

漆酶活化碱木质素的磺甲基化反应活性研究

采用漆酶对碱木质素进行活化预处理,并对活化碱木质素进行磺甲基化改性,揭示了漆酶活化对碱木质素磺甲基化反应活性影响的作用机理.采用顶空气相色谱、红外光谱、凝胶渗透色谱、核磁共振等研究了漆酶活化碱木质素的结构特征,结果表明,漆酶对碱木质素既有聚合作用又有解聚作用,分子量变化不大,多分散性增加;漆酶活化使得碱木质素发生脱甲基作用,酚羟基含量增大,紫丁香基含量减低;另外,漆酶可氧化酚羟基变成苯氧自由基使碱木质素聚合.采用分子模拟对漆酶活化碱木质素的电子云密度进行了计算,结果表明脱甲基作用增大了木质素苯环上的电子云密度,有利于磺甲基化反应的进行.采用电位滴定测试磺甲基化产物的磺化度来表征其反应活性的大小,结果表明漆酶活化磺甲基化碱木质素的磺化度提高了35%,且对二氧化钛悬浮体系的分散性能得到明显提高.     

造纸污泥中提取的木质素改性研究

为提高以造纸污泥为原料制备的木质素减水剂的减水性,用H2O2 和Na2SO3分别对木质素进行氧化、磺化.氧化工艺条件为:对10g木质素,过氧化氢用量为1.5g,反应温度80℃,pH=9,反应时间2 h.所得到的产品比一般磺化产品的减水性能优越,经检测各项主要指标达到普通减水剂的国家标准(GB8076-1997).     

水溶性聚合物改性水泥的研究：I.水溶性聚合物改进水泥流动性

制备了水解聚丙烯酰胺（ＨＰＡＭ）、磺甲基化聚丙烯酰胺（ＳＰＡＭ）及磺化聚苯乙烯（ＳＰＳ）等几种水溶性聚合物。研究了水溶性聚合物的种类、阴离子度、分子量、表面活性、掺量、ｐＨ值等因素对水泥净浆流动性的影响。结果表明阴离子聚合物及适中的阴离子度、分子量、掺量、ｐＨ值有利于水泥的分数，从而改善水泥的流动性。聚合物的电荷保护作用是影响水溶性聚合物改性水泥分散的主要因素。提出了聚合物分散水泥粒子与分子链性质     

MMP多肽交联磺化接枝甲基丙烯酸透明质酸水凝胶的制备及性能

为解决间充质干细胞定向分化和支架材料相容生长的问题，将透明质酸（HA）依次接枝甲基丙烯酸（MAA）、磺化和与金属蛋白酶（MMP）多肽交联，制备了MMP多肽交联磺化接枝甲基丙烯酸HA的水凝胶(MSMeHA, 1),其结构经¹H NMR, FT-IR, SEM和DMA表征。并研究了1的细胞毒性和蛋白携载性能。结果表明： 1具有薄壁多孔结构；1对蛋白吸附与携载能力明显优于未磺化的MMP多肽交联接枝甲基丙烯酸HA的水凝胶(MMeHA)。1在振荡负荷下的储能模量降低约54%。     

水溶性聚合物改性水泥的研究I.水溶性聚合物改进水泥流动性

制备了水解聚丙烯酰胺（ＨＰＡＭ）、磺甲基化聚丙烯酰胺（ＳＰＡＭ）及磺化聚苯乙烯（ＳＰＳ）等几种水溶性聚合物。研究了水溶性聚合物的种类、阴离子度、分子量、表面活性、掺量、ｐＨ值等因素对水泥净浆流动性的影响。结果表明阴离子聚合物及适中的阴离子度、分子量、掺量、ｐＨ值有利于水泥的分散，从而改善水泥的流动性。聚合物的电荷保护作用是影响水溶性聚合物改性水泥分散的主要因素。提出了聚合物分散水泥粒子与分子链性质相关的作用机理。     

13C核磁共振研究磺化脲醛树脂的反应机理

利用^13CNMR数据证实了在低磺化剂用量下脲醛树脂的磺化改性仍可发生,并对磺化脲醛（SUF）树脂制备过程中的羟甲基化、缩合、磺化及缩聚等各步反应机理进行了探讨.明确了SUF树脂的^13CNMR谱图中各峰位所对应的结构单元,认为3个未知峰的出现与磺化改性得到的一些新结构单元有关,并对它们的结构进行了推测.通过对比不同磺化和缩聚反应程度下得到的SUF产物的^13CNMR数据,对磺化和缩聚反应后某些结构的出现和消失进行了解释.     

氧化硅柱撑磺化磷酸-苯膦酸锆的合成及性能

以磷酸-苯膦酸锆为层板,合成并表征了硅柱撑的层柱磷酸-苯膦酸锆,并磺化了其中的苯环.磺化后的产物具有较高的酸量,在酯化反应中催化活性与硫酸相当.     

Pyrolysis GC/MS identification of halogenated furandiones and other products from chlorinated aqueous humic solutions

Summary Chlorination of drinking water often leads to undesirable byproducts. Little is known about the hydrophilic chlorinated fragments and the high molecular products. For the investigations presented here, solutions of fulvic acids were chlorinated which had been isolated from a brown water lake and from a groundwater rich in DOC. The fulvic acid-like part of the products was reisolated using XAD-2 resin. Both the original fulvic acid and the chlorinated product were analyzed by pyrolysis in combination with gas chromatography/mass spectrometry. A number of compounds was identified including furandiones and pyrandiones. However, it remains unclear whether the furanones and pyranones were already present in the chlorinated samples or whether these were formed during pyrolysis by elimination of water from dicarboxylic acids.Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday     

风化煤的化学降解

在Ｍｎ－Ｍｏ催化剂存在下用ＨＮＯ３氧化对风化煤进行了化学降解研究。考察一降解条件，氧化产物收率及组成性质，结果表明，与原煤相比，氧解产物中极性功能团大量增加，极性溶剂中抽提率显著提高。     

Iodine emission in the presence of humic substances at the water's surface

Humic substances that preferentially adsorb at the air/water interfaces of water or aerosols consist of both fulvic and humic acid. To investigate the chemical reactivity for the heterogeneous reaction of gaseous ozone, O(3)(g), with aqueous iodide, I(-)(aq), in the presence of standard fulvic acid, humic acid, or alcohol, cavity ring-down spectroscopy was used to detect gaseous products, iodine, I(2)(g) and an iodine monoxide radical, IO(g). Fulvic acid enhanced the I(2)(g) production yield, but not the IO(g) yield. Humic acid, n-hexanol, n-heptanol, and n-octanol did not affect the yields of I(2)(g) or IO(g). We can infer that the carboxylic group contained in fulvic acid promotes the I(2)(g) emission by supplying the requisite interfacial protons more efficiently than water on its surface.     

磺化间规聚苯乙烯的表征

间规聚苯乙烯(sPS)是一种新型结晶性工程塑料,熔点达270℃,具有结晶速度快、耐热性好、耐化学腐蚀性优良等特点,可广泛用于汽车、电子、机械等行业,极具开发意义,但是由于sPS脆性大,抗冲击性差,故通过化学改性在sPS的苯环上引入极性基团,用于制成共混合金与复合材料,是提高材料韧性,开拓sPS用途的重要途径。     

羟基酸引发ε-己内酯开环聚合的研究

研究了水、醇、羧酸存在下ε 己内酯开环聚合的情况 ,发现在适当温度下 (80℃ ) ,羧基并不引发ε 己内酯的开环聚合 ,但对羟基引发ε 己内酯开环聚合起加速作用 ,而且催化能力与酸度有关 .进而又对羟基酸(乙醇酸、DL 苹果酸、柠檬酸 )引发ε 己内酯开环聚合做了研究 ,合成了一系列含不同数目遥爪羧基的α 羟基 ω 羧基 (1,2 ,3)己内酯低聚物 (HCPCL) ,并对其结构做了酸值滴定、羟值滴定、UV、FTIR与1H NMR分析 .对羧基催化羟基引发ε 己内酯开环聚合的机理做了分析     

Ligand exchange and fluorescence quenching studies of the fulvic acid-iron interaction: Effects of ph and light

The effects of pH and light on the interaction between fulvic acid and iron have been investigated through studies of the kinetics of exchange of iron between fulvic acid and 1,10-pehnanthroline(a strong iron(II) complexing agent), and of the quenching of intrinsic fulvic acid fluorescence by iron in solutions of pH 4.0 and 6.5 containing an excess of fulvic acid. The results enable the iron-fulvic acid interaction to be described in terms of operationally defined iron-fulvic acid groupings, the proportions of which are markedly dependent on pH and light conditions. At pH 4.0 fulvic acid exhibits considerable reducing ability with the result that a substantial portion of iron is present in reduced, unbound form. Irradiation of fulvic acids at this pH markedly increases their reducing ability. Iron that is not reduced is present as small (ultrafilterable), strongly bound iron(III) complexes. Iron bound in this form is an effective quencher of intrinsic fulvic acid fluorescence. At higher pH, essentially all of the iron is relatively strongly bound, with most being in the form of large (non-ultrafilterable) iron(III)—fulvic acid groupings. These groupings are not altered significantly by irradiation and iron bound in this form is not a very effective quencher of intrinsic fulvic acid fluorescence.     

Negatively charged poly(vinylidene fluoride) microfiltration membranes by sulfonation

Negatively charged PVDF microfiltration membranes were prepared using direct sulfonation with chlorosulfonic acid. The effect of sulfonation on the surface chemical properties, morphology, pore size distribution, hydrophilicity, water uptake, pure water flux, fouling and rejection were investigated. As the sulfonation reaction time was furthered, the degree of sulfonation and ion-exchange capacity increased and the membranes became more hydrophilic due to introduction of sulfonyl groups to the membrane surface. Using X-ray photoelectron spectroscopy, the composition of sulfonyl group with respect to sulfur concentration increased with time. From the SEM and porosity measurements, both the untreated and treated membranes did not reveal a substantial change in its morphology. The pure water flux increased significantly having a decreasing intrinsic resistance trend with degree of sulfonation. Both fouling phenomena and rejection were enhanced, with fouling of charged poly(styrene sulfonic acid) molecules on the surface-modified membrane decreased and rejection values increased with increasing degree of sulfonation mainly due to the effective electrostatic repulsion between the negatively charged PSSA and the negatively charged membrane.     

Sulfonated Polyetherimide and Its Membranes

Polyetherimide(PEI) was sulfonated by chlorosulfonic acid for the first time. The sulfonated products were characterized by FT-IR, DSC, ion exchange capacity and water sorption measurement. The hydrophilicity of PEI was improved by the sulfonation. The PEI was blended with the sodium salt from of sulfonated PEI(SPEI) to prepare microporous membranes. The morphologies of the membranes were studied with Scanning Electron Microscope (SEM).