The N alkyl chitosans were prepared from chitosan through Schiff base formation and hydrogenation. The adsorption properties of N alkyl chitosans, bearing the same substitution degree but different carbon chain length...The N alkyl chitosans were prepared from chitosan through Schiff base formation and hydrogenation. The adsorption properties of N alkyl chitosans, bearing the same substitution degree but different carbon chain length and vice versa for Cu(Ⅱ), Hg(Ⅱ) and Pb(Ⅱ) have been investigated. It is found that chitosan derivatives of the same carbon chain length show the highest adsorption capacity for tested ions, when their substitution degree is ranged in 0 35～0 39. And among the chitosan derivatives bearing the same substitution degree, N pentyl chitosan shows the highest adsorption capacity towards mentioned ions.展开更多
合成了6种无灰、无磷环境友好型润滑油添加剂———长链烷基荒氨酸酯衍生物;采用IR,UV-Vis,1 H NMR,13 C NMR对添加剂进行结构表征;用热重分析仪考察添加剂的热稳定性和抗氧化性能;利用四球摩擦磨损试验机考察添加剂在液体石蜡中的承载...合成了6种无灰、无磷环境友好型润滑油添加剂———长链烷基荒氨酸酯衍生物;采用IR,UV-Vis,1 H NMR,13 C NMR对添加剂进行结构表征;用热重分析仪考察添加剂的热稳定性和抗氧化性能;利用四球摩擦磨损试验机考察添加剂在液体石蜡中的承载能力和抗磨性能。结果表明,所合成的润滑油添加剂具有优良的热稳定性能和较好的极压抗磨性能。展开更多
Wittig-Horner method for the synthesis of Vitamin A derivatives is improved:3-methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1,3(or 1,4)-pentadienyl phosphonate is reacted directly with C 5-aldehyde in synthesis and a d...Wittig-Horner method for the synthesis of Vitamin A derivatives is improved:3-methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1,3(or 1,4)-pentadienyl phosphonate is reacted directly with C 5-aldehyde in synthesis and a double bond rearrangment step catalysted by base is curtailed.展开更多
文摘The N alkyl chitosans were prepared from chitosan through Schiff base formation and hydrogenation. The adsorption properties of N alkyl chitosans, bearing the same substitution degree but different carbon chain length and vice versa for Cu(Ⅱ), Hg(Ⅱ) and Pb(Ⅱ) have been investigated. It is found that chitosan derivatives of the same carbon chain length show the highest adsorption capacity for tested ions, when their substitution degree is ranged in 0 35～0 39. And among the chitosan derivatives bearing the same substitution degree, N pentyl chitosan shows the highest adsorption capacity towards mentioned ions.
文摘合成了6种无灰、无磷环境友好型润滑油添加剂———长链烷基荒氨酸酯衍生物;采用IR,UV-Vis,1 H NMR,13 C NMR对添加剂进行结构表征;用热重分析仪考察添加剂的热稳定性和抗氧化性能;利用四球摩擦磨损试验机考察添加剂在液体石蜡中的承载能力和抗磨性能。结果表明,所合成的润滑油添加剂具有优良的热稳定性能和较好的极压抗磨性能。
文摘Wittig-Horner method for the synthesis of Vitamin A derivatives is improved:3-methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1,3(or 1,4)-pentadienyl phosphonate is reacted directly with C 5-aldehyde in synthesis and a double bond rearrangment step catalysted by base is curtailed.
