A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition.Macroporous strongly acidic styrol resin(D001) as a novel,...A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition.Macroporous strongly acidic styrol resin(D001) as a novel,efficient,cost-effective,and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions.The pyrroles were obtained in high yields in short reaction times.展开更多
A new and practical method of the D301 resin,a weak basic anion exchange resin with secondary amine functionality（Grade Matrix Structure：Styrene-DVB D301R）,used as base to Heck reactions catalyzed by palladium reag...A new and practical method of the D301 resin,a weak basic anion exchange resin with secondary amine functionality（Grade Matrix Structure：Styrene-DVB D301R）,used as base to Heck reactions catalyzed by palladium reagent without phosphine compound as ligand is described.It was found that the D301 resin used as base is an efficient and reusable base and can be regenerated and recycled in the reaction.The olefmation of heteroaryl halides prepared the corresponding products in good yields using D301 resin as base.展开更多
1 Introduction The Suzuki cross-coupling reaction is a powerful and versatile method for the generation of unsymmetrical biaryls from arylboronic acids and aryl halides in a single step. However, the reaction is usua...1 Introduction The Suzuki cross-coupling reaction is a powerful and versatile method for the generation of unsymmetrical biaryls from arylboronic acids and aryl halides in a single step. However, the reaction is usually performed in the presence of Pd catalyst along with phosphine ligand, which sometimes creates practical problems because organophosphines tend to be expensive, poisonous, and air sensitive. Recently, phos-phine-free ligands,展开更多
本文研究了镀锌钢板的无铬钝化液组成及钝化工艺对钢片涂层性能的影响。通过多种性能测试得出最佳钝化液组成为:钼酸钠17 g/L,丙烯酸树脂105 m L/L,硅酸钠18 g/L,硅烷偶联剂KH-560为50 m L/L,硫脲8 g/L,30%过氧化氢10 m L/L,钝化的最佳...本文研究了镀锌钢板的无铬钝化液组成及钝化工艺对钢片涂层性能的影响。通过多种性能测试得出最佳钝化液组成为:钼酸钠17 g/L,丙烯酸树脂105 m L/L,硅酸钠18 g/L,硅烷偶联剂KH-560为50 m L/L,硫脲8 g/L,30%过氧化氢10 m L/L,钝化的最佳条件为p H=5,钝化温度298.15 K,钝化时间25 min。对钝化涂层的厚度及结合力进行检测,并结合电化学测试发现,复合钝化涂层的耐蚀性强于铬酸盐钝化涂层。展开更多
Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-free polymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of react...Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-free polymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reaction condition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in the hydrosols is 2%. The maximum weight average molecular weight (M-w) of polymer that assures soap-free emulsion conversion into hydrosol is about 1.2 x 10(5)-1.3 x 10(5). The particle transforming process was investigated, and an obvious change of particle diameter and morphology was observed.展开更多
A novel method for removing boron with ion exchange resin from residual brines to manufacture boron-free magnesia is described. The concentration of boron in the target magnesia manufactured thereby from Qinghai salt...A novel method for removing boron with ion exchange resin from residual brines to manufacture boron-free magnesia is described. The concentration of boron in the target magnesia manufactured thereby from Qinghai salt lakes is lower than 5 mg/g, and the typical D50 size of product is 10.625 mm.展开更多
文摘A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition.Macroporous strongly acidic styrol resin(D001) as a novel,efficient,cost-effective,and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions.The pyrroles were obtained in high yields in short reaction times.
基金the financial support of the Natural Science Foundation of China(No.20572100)the open foundation of the key discipline of industrial catalysis of Zhejiang.
文摘A new and practical method of the D301 resin,a weak basic anion exchange resin with secondary amine functionality（Grade Matrix Structure：Styrene-DVB D301R）,used as base to Heck reactions catalyzed by palladium reagent without phosphine compound as ligand is described.It was found that the D301 resin used as base is an efficient and reusable base and can be regenerated and recycled in the reaction.The olefmation of heteroaryl halides prepared the corresponding products in good yields using D301 resin as base.
基金Supported by the Zhejiang Province Natural Science Foundation,China(No.Y407240)
文摘1 Introduction The Suzuki cross-coupling reaction is a powerful and versatile method for the generation of unsymmetrical biaryls from arylboronic acids and aryl halides in a single step. However, the reaction is usually performed in the presence of Pd catalyst along with phosphine ligand, which sometimes creates practical problems because organophosphines tend to be expensive, poisonous, and air sensitive. Recently, phos-phine-free ligands,
文摘本文研究了镀锌钢板的无铬钝化液组成及钝化工艺对钢片涂层性能的影响。通过多种性能测试得出最佳钝化液组成为:钼酸钠17 g/L,丙烯酸树脂105 m L/L,硅酸钠18 g/L,硅烷偶联剂KH-560为50 m L/L,硫脲8 g/L,30%过氧化氢10 m L/L,钝化的最佳条件为p H=5,钝化温度298.15 K,钝化时间25 min。对钝化涂层的厚度及结合力进行检测,并结合电化学测试发现,复合钝化涂层的耐蚀性强于铬酸盐钝化涂层。
文摘Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-free polymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reaction condition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in the hydrosols is 2%. The maximum weight average molecular weight (M-w) of polymer that assures soap-free emulsion conversion into hydrosol is about 1.2 x 10(5)-1.3 x 10(5). The particle transforming process was investigated, and an obvious change of particle diameter and morphology was observed.
文摘A novel method for removing boron with ion exchange resin from residual brines to manufacture boron-free magnesia is described. The concentration of boron in the target magnesia manufactured thereby from Qinghai salt lakes is lower than 5 mg/g, and the typical D50 size of product is 10.625 mm.
