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以A(1,2-碳硼烷)为原料,分别采用琼斯试剂氧化法、CO2法和ClCOOCH3(氯甲酸甲酯)法合成了D(1,2-二羧基碳硼烷);然后D和B(1,2-二羟甲基碳硼烷)进一步酯化缩聚后,成功合成了P6(聚1,2-二羧基碳硼烷-1,2-二羟甲基碳硼烷酯)。研究结果表明:3种合成方法均能成功合成D,其中CO2法是最理想的合成方法;碳硼烷基团的引入,有效提高了P6的耐热性能(N2气氛中P6失重5%时的热解温度为190℃,700℃时的残炭率为59%);P6在耐高温领域中具有良好的应用前景,也是制备耐高温型PU(聚氨酯)胶粘剂的宝贵原材料。 相似文献
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TEMPO体系对粘胶纤维的氧化过程研究 总被引:3,自引:0,他引:3
2,2,6,6-四甲基哌啶氧化物自由基(TEMPO)-NaClO-NaBr是一种新的选择性氧化体系,文章研究了该体系对粘胶纤维的氧化过程。CP/MAS13C-NMR反映该体系对粘胶纤维是C6位选择性氧化,并能完全氧化成纤维素糖醛酸;用CP/MAS13C-NMR、耗碱量法和酸碱中和法研究了反应过程中羧基含量的变化;粘度法对聚合度的研究显示,粘胶纤维的降聚现象在反应一开始就非常显著。 相似文献
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扩链剂二羟甲基丁酸及聚氨酯乳液的合成 总被引:1,自引:0,他引:1
本文探讨了合成二羟甲基丁酸的某些规律。讨论了氧化条件,如:氧化温度,氧化时间及氧化剂的用量对氧化反应的影响。用红外光谱及液相色谱对所合成的二羟甲基丁酸进行了分析。并对由二羟甲基丁酸制备聚氨酯乳液的性能作了初步的探讨。 相似文献
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以苯胺和自制钒钛酸为原料,ITO导电玻璃为基底,利用一步法和两步法分别制备了钒钛酸-聚苯胺薄膜修饰电极,系统地研究了该复合薄膜的成膜机理和电化学行为。实验结果表明,一步法比两步法制备过程简单,且钒钛酸能逐层固定在聚苯胺薄膜里。该修饰电极不仅保持了钒钛酸的电化学活性和电催化性能,并具有良好的稳定性。两种方法制备的薄膜修饰电极对酸性水溶液中的碘酸钾均具有显著的的电催化还原作用。 相似文献
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目的建立A群脑膜炎球菌荚膜多糖(Group A meningococcal polysaccharide,GAMP)排溢法ELISA,并进行验证及初步应用。方法采用改良过碘酸盐氧化法制备抗GAMP-HRP。以抗GAMP单克隆抗体包被酶标板,抗GAMP-HRP作为酶标抗体,建立检测GAMP的排溢法ELISA。采用棋盘滴定法确定包被抗体及酶标抗体的最佳工作浓度,并对其特异性、敏感性及重复性进行验证。采用建立的排溢法ELISA检测GAMP-TT系列层析样品中的GAMP抗原活性,并与传统一步法ELISA及二步法ELISA进行比较。结果建立的排溢法ELISA的包被抗体最佳浓度为20μg/ml,酶标抗体最佳工作浓度为1∶128。该方法的特异性良好,敏感性与一步法和二步法相当,批内和批间变异系数与一步法相当;该方法检测GAMP-TT层析样品中的GAMP抗原活性的结果与二步法ELISA基本一致。结论排溢法ELISA的操作步骤与一步法ELISA大致相似,但较二步法ELISA显著简化,其对一步法ELISA中Hooks效应的纠正效果与二步法ELISA相同。 相似文献
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综述了近年来国内外有关对乙酰氨基酚及其中间体对氨基酚的合成方法,通过对其合成方法(如二步法、一步法,重排法和生化法等)的比较,认为一步法合成将是对乙酰氨基酚生产的发展方向。 相似文献
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In this study, Fe2O3 thin films were deposited via one-step and two-step electrochemical deposition methods. The one-step method used a constant growth potential, and the two-step method used two continuous growth potentials during the deposition. The morphological, electrical, and structural properties of the thin films and the relationships of each property with the photoelectrochemical properties of the thin films from the two methods were analyzed and compared. We determined that the samples grown by the two-step method have better photoelectrochemical properties than those grown by the one-step method. In this study, we attempted to determine the optimum growth potentials for the one-step and two-step methods and the growth durations of the first and second stages in the two-step method in terms of the photoelectrochemical properties. The sample formed at ?0.05 V for 30 s in the first step and ?0.25 V for 2 min 30 s in the second step in the two-step method has the highest photocurrent density value of 0.28 mA/cm2 (at 0.5 V vs. SCE), which is higher than that of the samples grown by the one-step method. 相似文献
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Aqueous polyurethanes dispersions of nanometer size derived from various carboxylic polycaprolactonediols of different molecular weights, carboxylic diols, including 2,2‐di(hydroxymethyl)propanoic acid (DMPA), 2,2‐di(hydroxymethyl)butanoic acid (DMBA), and di(4‐isocyanatocyclohexyl)methane (HMDI) were prepared by a method in which the dispersing procedure was modified to enhance the molecular weight. The molecular weight, particle size, and UV–vis spectra of the polyurethane dispersions were investigated. The tensile properties of the cast films were determined. The modified dispersing procedure gave polyurethane dispersions with higher molecular weight and better tensile strength. As the molecular weight of the carboxylic polycaprolactonediol decreases, the content of the ionic groups increases, the particle size decreases accordingly. As the molecular weight of the carboxylic polycaprolactonediol used is 1000 g/mol or below, the polyurethanes dispersions become completely clear. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献