端-侧基氨基聚醚改性硅油的合成及其微乳液制备

采用本体聚合法,以自制环氧封端剂、D_4、3-缩水甘油丙基(二甲基)甲基硅烷为原料,四甲基氢氧化铵为催化剂,合成端-侧基环氧改性硅油,利用氨基与环氧基的氨解开环反应,将氨基聚醚引入,合成端-侧基氨基聚醚改性硅油,采用~1 H NMR及FT-IR证明产物合成。制备端-侧基氨基聚醚改性硅油微乳液,探讨了乳液参数对乳液平均粒径、表面张力及透光率的影响。     

预聚物法制备喷涂聚氨酯弹性体研究

本文以MDI、HMDI、IPDI、二胺扩链剂、端氨基聚醚、端羟基聚醚等为主要原料用预聚物法制备了双组分喷涂聚氨酯弹性体。探索了配方中异氰酸酯种类、NCO的含量、不同扩链剂和不同端羟基聚醚等因素对聚氨酯弹性体的影响。通过改变预聚体中多异氰酸酯类型及NCO的含量,调节配方中软硬段质量分数,选择聚醚多元醇和端氨基聚醚种类,以及合理搭配不同的扩链剂,可以制得不同性能的聚氨酯弹性体材料。     

高附着力聚脲胶粘剂的制备和性能

利用芳氨基的空间位阻效应,分别以芳香族端氨基聚醚、芳香族端氨基聚醚改性的HDI作为聚脲的A、B组分,制备了一种力学性能优异的聚脲胶粘剂。考察了A、B组分配比对胶粘剂力学性能的影响,并利用FT-IR光谱对涂层的氢键化程度进行了分析。研究结果表明,当B/A的质量比为1.55时,涂膜与金属铝材的附着力最高,达25.98MPa,其完善的氢键化程度仅为4.31%。说明芳环的引入降低了聚脲基团中NH的分子间氢键,而使其游离出来与金属底材形成胶粘点,从而提高了聚脲胶粘剂的附着性能。     

喷涂聚脲用羟氨基聚醚的制备及性能研究

通过聚丙二醇二缩水甘油醚和脂肪胺制备羟氨基聚醚,并利用FTIR对羟氨基聚醚的结构进行表征,结果显示有明显的氨基特征峰。用羟氨基聚醚合成了聚脲弹性体,利用DSC和TGA考察了产物的性能,并测试了产物的各项物理机械性能,结果表明羟氨基聚醚能有效降低聚脲的反应速率,制备的聚脲软硬段相混合程度较好,并且具有较好的力学性能。     

微波合成可降解聚天冬氨酸水凝胶的研究

以DL-天冬氨酸为原料,在微波作用下合成了聚丁二酰亚胺(PSI),研究了微波功率、作用时间对DL-天冬氨酸固相缩聚反应的影响,采用不同官能度的端氨基聚醚在微波下对聚丁二酰亚胺进行开环交联,获得了可生物降解聚天冬酰胺衍生物水凝胶,研究了聚醚用量对水凝胶溶胀性能的影响。实验结果表明,微波能够快速促进DL-天冬氨酸合成聚丁二酰亚胺。     

微波合成可降解聚天冬氨酸水凝胶的研究

以DL-天冬氨酸为原料，在微波作用下合成了聚丁二酰亚胺（PSI），研究了微波功率、作用时间对DL-天冬氨酸固相缩聚反应的影响，采用不同官能度的端氨基聚醚在微波下对聚丁二酰亚胺进行开环交联，获得了可生物降解聚天冬酰胺衍生物水凝胶，研究了聚醚用量对水凝胶溶胀性能的影响。实验结果表明，微波能够快速促进DL-天冬氨酸合成聚丁二...     

季铵化聚醚砜酮的制备及其膜性能

以浓硫酸为溶剂,氯甲基丁醚、三甲胺为改性试剂,通过氯甲基化／季铵化两步反应制备了季铵化聚醚砜酮(QAPPESK)。详细讨论了两步反应的影响因素。对氯甲基化聚醚砜酮(CMPPESK)进行了^1H—NMR核磁表征,测试了CMPPESK、QAPPESK的溶解性和5％热失重温度。将此材料制备成纳滤膜用于染料脱盐,并考察了其耐酸性和抗污染性,发现QAPPESK是较为优异的膜材料。     

高性能端芳香氨基聚醚/环氧树脂胶粘剂的研究

用端芳香氨基聚醚(ATPE)与E-44环氧树脂组成了高强、高韧的胶粘剂.研究了胶粘剂的固化反应和固化产物的交联密度、冲击断面形貌与力学性能,及其随ATPE化学结构变化的规律.结果表明,增大ATPE分子中聚醚链段长度(M^-PE),胶粘剂体系的固化温度和反应热焓值(ΔH)均提高;胶粘剂固化产物的综合力学性能随着M^-PE增大出现最佳值.改变ATPE中末端-NH2在苯环上的位置,发现3-ATPE体系的ΔH最大;2-ATPE体系的综合力学性能最佳.     

端硅烷基聚醚树脂的合成及其储存稳定性

利用端羟基聚丙二醇与3-异氰酸酯基丙基三甲氧基硅烷在少量催化剂作用下的一步反应,成功合成端硅烷基聚醚树脂。端硅烷基聚醚树脂中较高的水分含量以及遗留在树脂中的高活性催化剂二月桂酸二丁基锡的共同作用导致其储存稳定性较差,通过加入除水剂乙烯基三甲氧基硅烷、使用中等活性催化剂和适度调增反应温度等手段,可确保合成时间较短的前提下,获得储存稳定性和硫化性能均良好的端硅烷基聚醚树脂,该树脂可作为环保型硅烷改性聚醚密封胶用基础聚合物。     

超支化聚醚/丁羟聚氨酯互穿网络的制备及力学性能

本文采用阳离子开环聚合的方法,合成了端羟基超支化聚醚,并对其端基进行改性,调节超支化聚醚与丁羟聚氨酯的相容性。采用FT-IR,1H-NMR对改性前后超支化聚醚进行结构表征。HTPB型聚氨酯在改性超支化聚醚的存在下原位聚合形成超支化聚醚/丁羟聚氨酯互穿聚合物网络,力学性能测试结果表明,加入超支化聚醚可以明显提高HTPB型聚氨酯胶片的力学性能。其中加入30%第4代改性超支化聚醚时,其最大拉伸强度提高了3.86倍,达到2.65 MPa。最大延伸率提高了3.7倍,达到1868%。     

ODPA/BAPP型聚异酰亚胺及其衍生物的合成与性能表征

首先由二苯醚四酸二酐(0DPA)与4,4′-双(氨基苯氧基)丙烷(BAPP)经两步反应制得聚异酰亚胺(PⅡ),然后分别用丙烯酸羟乙酯(HEA)和正辛醇对所得PⅡ进行开环反应得到光敏的和非光敏的聚酰胺酯(PAE1和PAE2)。对聚异酰亚胺(PⅡ)的制备过程用红外进行了跟踪,并对聚异酰亚胺的热异构化、聚异酰亚胺衍生物的合成和产物的溶解性、热性能及膜性能进行了表征。     

碱式氯化镁晶须制备纳米氧化镁热分解动力学研究

采用水热法以氯化镁和氢氧化钙为原料制备了碱式氯化镁(BMC)晶须, 然后热解得到了纳米氧化镁。经透射电镜(TEM)和选区电子衍射(SAED)分析其粒径在20~40 nm之间, 暴露晶面族为{111}和{110}。通过热重差热分析(TG-DTA)、扫描电镜(SEM)、X射线衍射(XRD)以及红外光谱(FT-IR)分析确定了碱式氯化镁晶须热分解过程分四步进行, 前两步分别脱去两个结晶水, 第三步脱氯化氢, 最后脱羟基水。采用Satava法和微分法对BMC晶须的热分解机理和动力学进行了研究, 得出第一步反应热分解机理为随机成核与随后生长、第二步为二维扩散、第三步为相边界反应、第四步为一维相边界反应。     

Effect of inorganic salts on the inhibition of hydrolyzing halo‐ester in a two‐phase solution

Abstract

Effect of the inorganic salts on the conversion of halo‐ester (ethyl‐2‐bromoisobutyrate, EtOBuBr) hydrolyzing in an alkaline aqueous solution/organic solvent two‐phase medium was investigated. The rate of hydrolyzing EtOBuBr and the conversion are obviously affected by the inorganic salts. The experimental data verify the proposed mechanism of hydrolysis. The reaction steps which hydrolyze these bromo‐alkyl bonds (Br‐C bond) and ester functional groups (–COOR) are developed and discussed. A kinetic model of the main reaction steps was established in which the rate expressions were derived. The intrinsic rate constants of the reactions were determined from the experimental data of EtOBuBr hydrolysis via parameter estimation. The results indicated that the conversion of hydrolyzing EtOBuBr is highly dependent on the concentration of alkaline compound in the aqueous solution. It is also found that sodium carbonate, sodium chloride, sodium nitrate and sodium sulfate inhibit the reaction, while calcium carbonate enhances it. The corresponding rate constants of hydrolyzing EtOBuBr in a variety of inorganic salt concentrations were searched.     

Fabrication of gold nanoparticles using luminol as a reductive and protective reagent

An easy and simple reaction is employed to synthesize ligand-protected gold nanoparticles. In this reaction, luminol is used as a reductive and protective reagent to prepare gold nanoparticles in aqueous solution. It includes two steps: chemiluminescence and formation of gold nanoparticles. The formation processes were monitored by resonance light scattering spectroscopy, and the results were observed by transmission electron microscopy and x-ray photoelectron spectroscopy. Highly stable gold nanoparticles about 110 ± 2 nm in size can be readily obtained. A new insight into the design of water-soluble ligand-protected gold nanoparticles for biomedical, analytical, and catalytic applications has been provided. The text was submitted by the authors in English.     

氯磺化聚乙烯的降解动力学

通过热重分析仪研究了不同氯硫含量的氯磺化聚乙烯(CSM)在不同升温速率下的热分解行为。采用Ozawa及Kissinger方程研究了氯磺化聚乙烯的降解动力学,研究发现CSM的热降解过程包括两个主要失重平台,而且氯磺化聚乙烯的热分解反应不是一级反应。Ozawa方程计算的活化能随着产物中氯硫含量的增加从304.661kJ/mol下降到292.573kJ/mol。Kissinger方程计算的活化能分别为282.785kJ/mol和274.176kJ/mol。ln(β/Tm2)对1/Tm作图得一直线,证明氯磺化聚乙烯的热分解符合无规分解模型。     

Detailed study on the use of electrospray mass spectrometry to investigate speciation in concentrated silicate solutions

Silicate speciation in aqueous solutions containing tetraalkylammonium hydroxide as template is examined by electrospray mass spectrometry. A thorough study has been carried out to define and optimize the conditions of analysis for a highly concentrated reaction solution of inorganic species--in this case, silicate oligomers--by using different ion source designs. The results reveal specific advantages with respect to the detected species. Condensation of monomers leads to oligomeric units that condense further in different reaction steps to larger species. Potential gas-phase reactions that can disturb characterization of the formed silicate species were intensively investigated and characterized. One reaction that plays a key role is the alkoxylation of Si-OH groups that is caused by two different reactions: first, a reaction of methanolate from the solvent and, second, by the involvement of the template salt, tetramethylammonium hydroxide.     

水热还原法制备Ag@C壳核纳米结构及其表征

以棉花纤维制备的纤维素微晶为碳源,采用水热还原法制备了Ag@C壳核结构纳米颗粒,并用扫描电子显微镜、投射电子显微镜、X射线能谱仪、X射线衍射仪对产品进行表征,结果表明,所得产品为Ag@C核／壳结构纳米颗粒,外壳是碳层,内核为纳米银颗粒。最佳的制备条件是,180％反应15h,pH=1-2,纤维素微晶的浓度为0．083g／L。讨论了碳包银核／壳结构的生长机理,     

UV 喷墨墨水用聚氨酯丙烯酸酯的合成及过程控制

采用本体法,以异佛尔酮二异氰酸酯(IPDI)、聚乙二醇(PEG)、丙烯酸羟丙酯(HPA)为原料,合成了低黏度、快速固化的UV 固化聚氨酯丙烯酸酯预聚体。用红外吸收光谱对其化学结构进行了表征,并分析了温度、催化剂、阻聚剂等因素对反应过程及产物性能的影响。     

Effect of the Type of Base and Number of Reaction Steps on the Degree of Quaternization and Molecular Weight of N-Trimethyl Chitosan Chloride

N-Trimethyl chitosan chloride (TMC), a chemically modified derivative of chitosan, is the first chitosan derivative shown to be an effective absorption enhancer for peptide and protein drugs across mucosal epithelia. TMC is synthesized by reductive methylation with methyl iodide in the presence of a strong base such as sodium hydroxide. In this reaction, the primary amino group on the C-2 position of chitosan is changed to a quaternary amino group. The charge density, as determined by the degree of quaternization, and probably also the molecular weight of TMC are important factors that influence the absorption enhancement effect and toxicity of this polymer. The molecular weight of the starting polymer decreases during the synthesis procedure due to factors such as the strong alkaline environment and elevated experimental temperatures. This study investigated the effects of two different bases, sodium hydroxide and dimethyl amino pyridine, together with a varying number and duration of reaction steps, on the degradation and the degree of quaternization of TMC polymers. ¹H-NMR (nuclear magnetic resonance) spectra showed a major increase in the degree of quaternization (21%-59%) of TMC with an increase in the number of reaction steps when sodium hydroxide was used as the base. Intrinsic viscosity values indicated that the use of dimethyl amino pyridine did not cause polymer degradation to the same extent as sodium hydroxide, but that the degree of quaternization of TMC stayed low (7.3%-9.6%) even when the number of reaction steps was increased. A combination of the two bases did not reduce polymer degradation, while the degree of quaternization was limited to relatively low values (12.5%-34.4%).     

两步法LDPE/HSS表面光接枝的研究

采用两步表面光接枝方法研究了乙烯基苯磺酸(HSS)在低密度聚乙烯(LDPE)膜表面的接枝聚合,使LDPE膜表面有效强酸化．探讨了各反应条件对表面接枝的影响规律,利用称量法、表面水接触角测定法、红外光谱分析、扫描电镜观察等手段对表面接枝膜进行了表征。