在“高聚物的结构与性能”课程中讲透高聚物的特点

通过对高分子链的柔性、聚合物独有的熵弹性、显著的粘弹性、特有的描述链段运动的WLF方程,可能实现的大尺寸取向和小尺寸解取向、银纹、单链凝聚态、折叠链片晶和伸直链晶体、分子量的多分散性、高分子溶液特性和高聚物熔体的弹性行为等的讨论,希望能突出“高聚物的结构与性能”课程中高聚物的特点。     

PIXE法分析共聚物中痕量氯

四氟乙烯和全氟4-甲基-3,6-二氧杂-△~7辛基磺酰氟在溶剂氟里昂-113(F-113)中进行自由基引发聚合反应时,共聚物(T-O)是否有链转移,可以通过测定所得共聚物中的含氯量来得以证实。我们首次应用质子X萤光分析法(PIXE)进行分析。结果表明,共聚物中含氯量小于1ppm,F-113溶剂并未发生链转移。同时,我们测定了已证明有F-113参与链转移反应的F_(40)试样,含氯量高达700ppm。     

阳离子无皂含氟丙烯酸酯的合成与表面性能

在合成甲基丙烯酸全氟辛酰氧基乙酯(FA)基础上,用半连续法制备了无皂阳离子含氟丙烯酸酯乳液。当乳液的粒径在100~200 nm、ζ电位大于40 mV时,乳液较稳定。阳离子亲水单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)在含氟丙烯酸酯中质量分数为0.10~0.18、固含量小于20%时乳液的稳定性好,且随DMC含量的增加稳定性提高;含氟丙烯酸酯乳胶膜的附着力与耐磨性好,乳胶膜的透湿率随DMC的增加而增加。随热处理温度的提高,膜表面自由能下降;经160℃热处理后膜发生了交联,表面自由能为18 mN/m,与聚四氟乙烯(PTFE)的表面能相近,DMC含量对膜表面自由能影响不大。XPS分析也表明膜表面氟含量随热处理温度的提高而增加。     

硝酸银及其产物银对六角相液晶流变性影响

用偏光显微镜测定了硝酸银及其产物银对NP－10／水六角相区的影响，用动态 （应力和频率扫描）和稳态（蠕变－恢复）方法研究了硝酸银的加入和银的生成对 该体系粘弹性的影响。无机前驱物硝酸银和银的生成能使六角相区略缩，动态流变 实验表明，无机物引入纯六角相液晶体系中会使其抗剪切的能力降低，对相区两侧 影响与振荡所采用的频率有关。生成的银原子会在胶束表面聚集，增加了胶束内部 不同EO链之间的交联，造成松弛时间变长，粘弹性指数降低，稳态实验所得到的结 果与动态实验一致，并将粘性和弹性定量化。用弹簧－粘壶模型和液晶的空间构型 及作用力解释了实验结果。     

三配位[CuCl_3]~-的电子结构、化学键和配位化学性质

用INDO法从正则分子轨道和定域分子轨道讨论了[CuCl_3]~-的电子结构和化学键,铜的4p轨道对成键贡献最大,3d轨道不参与成键。根据[CuCl_3]~-的HOMO和LUMO的原子轨道成份,讨论了它的配位化学性质。     

有机铵盐对FC-SAA表面活性及溶度的影响

测定了一系列有机铵盐与一种全氟烷磺酸盐１：１混合体系水 溶液的表面张力，由此研究有机铵盐对碳氟表面活性剂表面活性及溶度的影响，导出应用于此种混合体系的Ｇｉｂｂｓ吸附公式，并讨论了混合体系中两表面活性组分的表面分子相互作用和表面层的结构。     

BLUE LIGHT-EMITTING COIL-ROD-COIL BLOCK OLIGOMERS WITH RIGID p-HEXAPHENYL AS CHROMOPHORE

The synthesis and characterization of coil-rod-coil triblock oligomers, poly（ethylene oxide）-b-p-hexaphenyl-b- poly（ethylene oxide）, are described. The number of repeating ethylene oxide units in each flexible block are 3 （EO3-PHP- EO3）, 8 （EOs-PHP-EO8）, 13 （EO13-PHP-EO13）, and 17 （EO17-PHP-EO17）, respectively. The structures of these oligomers are confirmed by ^1H-NMR, 13C-NMR, EA, and MALDI-TOF mass spectrometry. The introduction of soluble poly（ethylene oxide） coils to the rigid p-hexaphenyl segment significantly improves the solubility of the oligomers, so they can form smooth thin films by spin-coating from their solutions. The oligomers are quite thermally stable and have 1% weight loss temperatures at above 340℃ under nitrogen. They can emit strong blue light in both solution and film state, and have fluorescence quantum yields of about 40% in chloroform. They are expected to have potential applications in optoelectronic devices.     

四唑及其衍生物的理论研究Ⅷ: 硝氨四唑衍生物的从头算

运用从头计算法,在HF/6-31G^*水平下,全优化计算了7种硝氨四唑衍生物的分子几何和电子结构。结果表明,标题物的四唑环近似为平面构型;2H式中性分子的芳香性大于相应的1H式异构体。5-硝氨-1H四唑分子内氢键使硝氨基与环共面;其余标题物中硝氨基与环垂直。不同水平下的总能量计算表明,标题物中电子相关效应显著;1H式中性分子较2H式的能量高,5-硝氨四唑负离子在三个负离子中最稳定。根据电荷分布阐明了四唑环质子化位置和标题物与金属的配位方式。此外还计算了各标题物的红外光谱及热力学性质。     

Poly（meta-phenylene） Derivative with Rigid Twisted Biphenyl Units in Backbone： Synthesis, Structural Characterization, Photophysical Properties and Electroluminescence

A soluble poly(meta-phenylene)derivative with rigid twisted biphenyl unit was synthesized by the Yamamoto coupling reaction.The polymer is soluble in common organic solvents,and the number-average molecular weight is about 6500.The UV-Vis and quantum chemical calculation indicate that the different conformation segments named "conformers" exist in the polymer backbones;it was also further confirmed by the single crystal X-ray diffraction study of the dimeric model compound.The π-π transition of biphenyl segments of twisted and planar conformations made the polymer exhibit a strong absorption around 256 nm and a weak absorption at about 300 nm.Furthermore,the polymer exhibits a strong UV photoluminescence at 372 nm when the excitation wavelengths are longer than 300 nm.The ultraviolet-emitting electroluminescence(EL)device with the single layer structure shows EL λmax of the derivative at 370 nm.     

呋喃西林水溶液在光和热作用下的稳定性

The influence of both light and heat on the stability of nitrofurazone aqueous solution was studied. Results show that in either heating experiments or the exposure to light at high temperatures, the degradation rate obeyed zero-order kinetics. The total rate constant ktotal caused by both light and heat can be divided into two parts: ktotal =kdark klight, where kdark and klight are the degradation rate constants caused by heat and light, respectively. The klight can be expressed as klight=Alight*exp(-Ea,light/RT)*E, where E is the illuminance of light, and Alight and Ea,light both are experimental constants. The values of these kinetic parameters were determined based on the experiments in the dark and upon exposure to three different light sources. Results show that the values of Alight and Ea, light varied with the light source. To save time, labor, and drugs, exponential heating experiments were employed and compared with the isothermal experiments. Results indicated that kinetic parameters obtained by exponential heating experiments are comparable to those obtained by isothermal experiments either in the dark or upon exposure to light.