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1.
Monomers and their polymers containing 3-arylcarbazolyl electrophores have been synthesized by the multi-step synthetic route. The materials were characterized by thermo-gravimetric analysis, differential scanning calorimetry and electron photoemission technique. The polymers represent materials of high thermal stability having initial thermal degradation temperatures in the range of 331–411 °C. The glass transition temperatures of the amorphous polymeric materials were in the rage of 148–175 °C. The electron photoemission spectra of thin layers of monomers showed ionization potentials in the range of 5.6–5.65 eV. Hole-transporting properties of the polymers were tested in the structures of organic light emitting diodes with Alq3 as the green emitter. The device containing hole-transporting layers of polyether with 3-naphthylcarbazolyl groups exhibited the best overall performance with a maximum current efficiency of 3.3 cd/A and maximum brightness of about 1000 cd/m2. 相似文献
2.
H-bond and conformations of donors and acceptors in model polyether based polyurethanes 总被引:1,自引:0,他引:1
The molecular mechanics (MM) method with COMPASS force field was used to study the H-bonds in the polyether based polyurethane model molecules. Availability of the calculation was firstly verified in comparison of some H-bonded model molecules, which were studied by using ab initio calculation, and those calculated by MM. Based on a urethane model molecule 1,3-dimethylcarbamate, which can be donor or acceptor and behaves in various conformations, it is reasonable to have a large number of H-bond interactions between various conformational donors and acceptors. For examining all the possible interaction patterns, we studied 57H-bond complexes. This systematic modeling covers well-known four types of interaction patterns, such as NH?OC (Type I), NH?O-CO (Type II), NH?NH (Type III), NH?COC (Type IV) in the system. Obtained H-bond energies were used to analyze the probabilities of the complexes. For the interaction within the hard segments, or Type I, Type II and Type III, a predominant H-bond complex has been found in the present study, which belongs to Type I. For the interaction between the hard segment and the soft segment, two conformations of Type IV were calculated to be existed. 相似文献
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4.
M.S. Thompson Author Vitae Author Vitae 《Polymer》2008,49(2):345-373
Poly(ethylene oxide) (PEO) oligomers are employed extensively in pharmaceutical and biomedical arenas mainly due to their excellent physical and biological properties, including solubility in water and organic solvents, lack of toxicity, and absence of immunogenicity. PEO can be chemically modified and reacted with, or adsorbed onto, other molecules and surfaces. Sophisticated applications for PEO have increased the demand for PEO oligomers with tailored functionalities, and heterobifunctional PEOs are often needed. This review discusses the synthesis and applications of heterobifunctional PEO oligomers possessing amine, carboxylate, thiol, and maleimide functional groups. 相似文献
5.
本法采用乙醇水溶解试样,以经过处理的无钾,钠离子聚醚鸩元醇作为基体,配制标准样品,用火焰光度法检测聚醚多元醇中间品的钾(钠)离子的含量。由于样品处理简单,应用浓度直读取数据,可快速准确地测定试样,适用于聚醚多元醇生产过程中间品的检验。 相似文献
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分析了高聚物的氧化裂解机理及抗氧化剂的作用原理。选择了对提高共聚醚酯的热稳定性较为有效的复合抗氧化剂,用测定该共聚醚酯的特性粘度和端羧基含量改变的方法来表征分子量的变化,证实了抗氧剂的作用机理和复合抗氧化剂之间的协同效应 相似文献
8.
Houjian Gong Long Xu Guiying Xu Teng Zhu Mingzhe Dong 《Journal of surfactants and detergents》2019,22(2):217-228
The effect of sodium benzoate and sodium chloride on the aggregation behavior of PEO-PPO-ph-PPO-PEO (BPE) and PPO-PEO-ph-PEO-PPO (BEP) polyethers at the air/water interface was investigated by measuring the equilibrium surface tension, surface dilational viscoelasticity, and surface tension relaxation. The measurements of surface tension showed that sodium benzoate has a better effect on decreasing the surface tension of BPE and BEP solutions than NaCl, especially when the polyether concentrations are low. According to dilational viscoelasticity measurements, the concentration of BPE required for the maximum dilational modulus is lower than that of BEP, indicating that BPE more easily forms a compact adsorbed layer. The dilational modulus values of BPE solutions in the presence of sodium benzoate and NaCl first increase and then decrease after passing through a maximum, and then they increase again with increasing electrolyte concentration. On the other hand, the dilational modulus values of BEP solutions in the presence of sodium benzoate and NaCl first increase to a maximum and then decrease with increasing electrolyte concentration. The surface tension relaxation results are consistent with those of dilational viscoelasticity. The different effects of sodium benzoate and NaCl on the polyether aggregation behaviors are caused by the strong hydrophobic and π-π interactions between polyethers and sodium benzoate. This work has a great importance for the application and development of polyethers. 相似文献
9.
收集了2018年7月~2019年6月世界工程塑料和特种工程塑料工业的相关资料,介绍了2018~2019年世界工程塑料和特种工程塑料工业的发展情况,按工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯)和特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮、聚芳砜、聚邻苯二甲酰胺)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。 相似文献
10.
采用软化剂与降低TDI指数相结合的方法制备了中等密度的超软聚氨酯泡沫,泡沫性能和当前的软化剂与二氯甲烷结合体系的相当。使用自制聚醚多元醇,全水发泡,制备了高密度超软PU泡沫,25%压陷硬度25~38N,65%/25%压陷比大于2.8。 相似文献