Influence of HMTA ligand in MMA AGET ATRP emulsion polymerization

Interactions of hexamethylenetetramine ligand in atom transfer radical polymerization initiated by activator generated by electron transfer were studied. Polymerization of methyl methacrylate was done using two-step experimental procedure in 2 L emulsion batch reactor at 50, 60, and 80°C. The selection of reactant ratios was quite challenging for a reactor of this size. Replicate runs were conducted for data reproducibility purpose. Gravimetry method and gel permeation chromatography were used to determine monomer conversion, Mn, and PDI of polymer samples. PMMA produced was also characterized by means of dynamic light scattering, Fourier-transform infrared spectroscopy and nuclear Magnetic Resonance spectroscopy. Results showed high monomer conversion up to 93% and Mn ranging 243–274 kg/mol with PDI from 1.45 to 1.60. Besides, combining HMTA with sodium dodecyl sulfate, an anionic surfactant, a well-controlled polymer with a lower Mn of 201 kg/mol and PDI of 1.56 was obtained in 3 hr reaction time.     

六次甲基四胺对电镀锌电沉积过程的影响

采用循环伏安法和电化学阻抗谱,分析了六次甲基四胺对锌电沉积过程的影响。循环伏安测试结果表明:六次甲基四胺的加入使得锌的电沉积电位负移,说明六次甲基四胺在金属基体活性位点的吸附,使得锌电沉积的形核和生长需要在更大的阴极过电位下发生。同时六次甲基四胺提高了电沉积锌层在腐蚀介质中的耐蚀性。     

5-硝基水杨醛的合成研究

以对硝基苯酚、乌洛托品、多聚甲醛等为原料合成5-硝基水杨醛,主要探讨了反应温度、时间、反应物用量及酸等因素对合成产率的影响。较优反应条件为：在对硝基苯酚为0.02 mol（2.78 g）的情况下,多聚甲醛用量为0.4 g,冰醋酸和乙酸酐分别为15 mL和8 mLn,（六亚甲基四胺）：n（对硝基苯酚）=2∶1,反应时间为4.0 h,反应温度为90℃,此时反应产率可达78.9%。产品经IR表征。     

相转移催化合成氨基乙酸

以氨水、氯乙酸为原料，以六亚甲基四胺为相转移催化剂，在常温、常压下合成了氨基乙酸。考察了催化剂六亚甲基四胺和温度对合成氨基乙酸反应的影响。在温度５８℃、催化剂用量为氯乙酸的３％、反应原料质量配比为氨水∶氯乙酸＝１∶５的条件下，产品收率为６８８％，纯度达９９６％。     

Hexamethylenetetramine: A New Fuel for Solution Combustion Synthesis of Complex Metal Oxides

Hexamethylenetetramine, (CH₂)₆N₄ (HMT) has been employed as a fuel for the first time to synthesize several binary, ternary, and quaternary oxides by the solution combustion method. Technologically important oxides, namely, zirconia, ceria, and their solid solutions, -Al₂O₃, Cr³⁺-doped -Al₂O₃, spinels, MAl₂O₄ (M = Ca, Mg, Zn and Ni), perovskites, LaMO₃ (M = Mn, Cr and Al), La_0.67Sr_0.33MnO₃, and La_0.67Ca_0.33MnO₃, have been synthesized. The oxides synthesized are characterized by X-ray powder diffraction, resistivity, fluorescence spectra, particle size, and surface area measurements. Decomposition of nickel nitrate-HMT complex has been investigated by TG, DTA, TPD, and evolved-gas analysis to elucidate the mechanism.     

2,4-双(辛基硫亚甲基)-6-甲基苯酚的合成

以邻甲酚、正辛硫醇和多聚甲醛为原料,以六次甲基四胺为催化剂、N,N-二甲基甲酰胺(DMF)为溶剂,在氮气气氛中采用一步法合成了2,4-双(辛基硫亚甲基)-6-甲基苯酚。采用4因素3水平正交实验研究了原料配比、反应时间、反应温度和催化剂用量等因素对合成反应的影响,并通过单因素实验得到了最佳反应条件,即邻甲酚75 mmol、n(邻甲酚):n(正辛硫醇):n(多聚甲醛)=1.00:2.10:4.20、催化剂用量7mmol、DMF 22mL、反应温度110℃、反应时间9h;在此条件下,2,4-双(辛基硫亚甲基)-6-甲基苯酚收率为93.46%。产品经IR表征和元素分析确证为目标化合物。     

六次甲基四胺、邻苯二甲酸、咪唑和Cu(Ⅱ)配合物的合成及单晶培养

六次甲基四胺(hmt)、邻苯二甲酸与咪唑(im)和金属离子配位可形成一系列的配合物,本文重点介绍了六次甲基四胺、邻苯二甲酸与Cu(Ⅱ)(im)4(NO3)2以乙醇-水为溶剂,采用常温溶剂蒸发法合成标题配合物及培养出其单晶.     

均匀共沉淀法合成纳米Gd2O3：Eu粉体及其发光特性

以六次甲基四胺（hexamethylenetetramine,（CH2）6N4,HMT）为沉淀剂,在GdCl3和EuCl3混合溶液中,利用均匀共沉淀法制得了纳米颗粒.结果表明,获得的Gd2O3：Eu纳米颗粒近似为球形,尺寸均匀,平均粒径为100 nm,且每个球形颗粒由平均粒径为20 nm的微晶聚并而成.Gd2O3：Eu荧光粉在波长612 nm的红光发射来自Eu^3＋的5D0-7F2电偶极跃迁,发光强度随煅烧温度提高而增强,随Eu^3＋掺杂摩尔分数的提高而增强.Eu^3＋掺杂摩尔分数超过7%时,发生浓度淬灭,发光强度减弱.     

Controlled accommodation of metal nanostructures within the matrices of polymer architectures through solution-based synthetic strategies

Controlled accommodation of metal nanostructures (MNSs) into the matrix of a well-defined polymer architecture offers an effective approach to achieve hierarchically structured nanocomposites with tunable synergistic properties to broaden application potentials in the emerging fields of energy, environmental science, and medicine. This review focuses on the recently developed zero-dimensional and one-dimensional MNSs@polymer hybrid nanostructures obtained by solution-based synthetic strategies. Progress in the controlled synthesis of those hybrid nanostructures in terms of the number (e.g., monomer, dimer and trimer), organization manner (e.g., linear alignment or confined assembly in certain domains), and spatial arrangement (e.g., in the core and shell) of the MNSs within the distinct polymer matrices are detailed. The synergistic properties and potential applications of those MNSs@polymer hybrids associated with their compositions and morphologies are also reviewed.     

改性剂对废胶粉/高密度聚乙烯热塑性弹性体性能的影响

研究废胶粉(WRP)改性剂对共混型WRP/高密度聚乙烯(HDPE)热塑性弹性体性能的影响。结果表明:采用间苯二酚/六亚甲基四胺(质量比1/0.7)、偶联剂Si69和偶联剂KH-550改性WRP,且质量分数分别为6%,9%和6%时,热塑性弹性体综合性能较好;3种改性剂中间苯二酚/六亚甲基四胺的改性效果最佳。