Precursor(SnC2O4)was prepared by ball-milling solid chemical reaction between oxalic acid and stannous chloride at ambient temperature,and SnO2 was obtained by thermal decomposition of the precursor.The x-ray diffract...Precursor(SnC2O4)was prepared by ball-milling solid chemical reaction between oxalic acid and stannous chloride at ambient temperature,and SnO2 was obtained by thermal decomposition of the precursor.The x-ray diffraction was used to analyze the phase of the precursor and decomposition products,TG-DTA was used to analyze the change of the precursor in the process of pyrogenation,and SEM was used to analyze the shape of the decomposition products.Then the mechanism of ball-milling solid reaction between oxalic acid and stannous chloride was discussed,and the effect of temperature on the decomposing process was studied.The results show that the decomposition products vary in component and size according to different decomposition temperature.Spherical nano-SnO2 about 100nm is obtained by decomposition of the precursor at 600℃.展开更多
Stannous oxalate was prepared efficiently and characterized by XRD and FT-IR. It exhibited higher catalytic activity and had profitable effect than tetrabutyl titanate and stannous octoate for the synthesis of polytri...Stannous oxalate was prepared efficiently and characterized by XRD and FT-IR. It exhibited higher catalytic activity and had profitable effect than tetrabutyl titanate and stannous octoate for the synthesis of polytrimethylene terephthalate （PTT） via esterification-route. Over this catalyst, the degree of esterification of pure terephthalic acid was up to 94.4% at 260 ℃ after 1.5 h,while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PTT polyester, polymerized at 260 ℃,60 Pa for 2 h, was 0.8950 dL/g and 15 mol/t, respectively. Stannous oxalate was a promising catalyst for the synthesis of PTT polyester.展开更多
A complete study on the catalytic activity of stannous oxalate for poly(trimethylene terephthalate) (PTT) synthesis via esterification method is carried out by comparison to the well known catalysts (tetrabutyl titana...A complete study on the catalytic activity of stannous oxalate for poly(trimethylene terephthalate) (PTT) synthesis via esterification method is carried out by comparison to the well known catalysts (tetrabutyl titanate (TBT), dibutyltin oxide (Bu2SnO), and stannous octoate (SOC)). Their catalytic activity in the esterification process is monitored by measuring the amount of water generated, while intrinsic viscosity (IV) and content of terminal carboxyl groups (CTCG) are used as the index in the polycondensation process. Stannous oxalate shows higher activity than the other catalysts. Decrease in reaction time and improvements in PTT property are observed. The higher catalytic activity of stannous oxalate is attributed to its chelate molecular structure.展开更多
文摘Precursor(SnC2O4)was prepared by ball-milling solid chemical reaction between oxalic acid and stannous chloride at ambient temperature,and SnO2 was obtained by thermal decomposition of the precursor.The x-ray diffraction was used to analyze the phase of the precursor and decomposition products,TG-DTA was used to analyze the change of the precursor in the process of pyrogenation,and SEM was used to analyze the shape of the decomposition products.Then the mechanism of ball-milling solid reaction between oxalic acid and stannous chloride was discussed,and the effect of temperature on the decomposing process was studied.The results show that the decomposition products vary in component and size according to different decomposition temperature.Spherical nano-SnO2 about 100nm is obtained by decomposition of the precursor at 600℃.
文摘Stannous oxalate was prepared efficiently and characterized by XRD and FT-IR. It exhibited higher catalytic activity and had profitable effect than tetrabutyl titanate and stannous octoate for the synthesis of polytrimethylene terephthalate （PTT） via esterification-route. Over this catalyst, the degree of esterification of pure terephthalic acid was up to 94.4% at 260 ℃ after 1.5 h,while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PTT polyester, polymerized at 260 ℃,60 Pa for 2 h, was 0.8950 dL/g and 15 mol/t, respectively. Stannous oxalate was a promising catalyst for the synthesis of PTT polyester.
基金Supported by the National High Technology Research and Development Program of China 863 Plan (Grant No. 2003AA321010) the Innovation Research Fund of Graduate University, Chinese Academy of Sciences (2006)
文摘A complete study on the catalytic activity of stannous oxalate for poly(trimethylene terephthalate) (PTT) synthesis via esterification method is carried out by comparison to the well known catalysts (tetrabutyl titanate (TBT), dibutyltin oxide (Bu2SnO), and stannous octoate (SOC)). Their catalytic activity in the esterification process is monitored by measuring the amount of water generated, while intrinsic viscosity (IV) and content of terminal carboxyl groups (CTCG) are used as the index in the polycondensation process. Stannous oxalate shows higher activity than the other catalysts. Decrease in reaction time and improvements in PTT property are observed. The higher catalytic activity of stannous oxalate is attributed to its chelate molecular structure.
