The novel alkaline metal complex Ca（BPDCH）2 （1, BPDCH2 = 2,2＇-bipyri- dine-5,5＇-dicarboxylic acid） has been synthesized by the hydrothermal reaction of Ca（NO3）2·4H2O with 2,2＇-bipyridine-5,5＇-dicarboxyl...The novel alkaline metal complex Ca（BPDCH）2 （1, BPDCH2 = 2,2＇-bipyri- dine-5,5＇-dicarboxylic acid） has been synthesized by the hydrothermal reaction of Ca（NO3）2·4H2O with 2,2＇-bipyridine-5,5＇-dicarboxylic acid. The molecular and crystal structures of complex 1 have firstly been characterized by FTIR, elemental analysis, and X-ray single-crystal diffraction. The 3D MOF structure of complex 1 was interpreted by the versatile binding modes-the intermolecular hydrogen bonds and π-π stacking interactions of 2,2＇-bipyridine-5,5＇-dicarboxylic acid ligand. The analysis results show complex 1 belongs to a coordination polymer with 3D MOF structure. The results of thermogravimetric analysis and solubility demonstrate complex 1 is a thermostable compound and does not dissolve in water and traditional organic solvents.展开更多
This paper presents the thermal analysis of artificial sweeteners, and natural sugar substitutes. Thermal analysis was done on commercial compositions of sweeteners using simultaneous DSC/TGA (SDT). Heat flow, and mas...This paper presents the thermal analysis of artificial sweeteners, and natural sugar substitutes. Thermal analysis was done on commercial compositions of sweeteners using simultaneous DSC/TGA (SDT). Heat flow, and mass vs. temperature and time thermograms, along with DSC peak enthalpies and transition temperatures are reported. A number of the sweeteners were found to undergo transitions and reactions before or at 190°C (375°F, normal baking temperatures) and all dextrose containing sweeteners show an endothermic peak around 80°C due to the liberation of bound water molecules. The major components of sweeteners studied were found to be generally thermostable at or below 100°C.展开更多
Abstract Biodegradable poly（ether-imide-ester） elasto- mers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N＇,N-bis（2-carboxyethyl）- pyromellitimide which was derived from pyrom...Abstract Biodegradable poly（ether-imide-ester） elasto- mers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N＇,N-bis（2-carboxyethyl）- pyromellitimide which was derived from pyromellitic dianhydride and glycine. The chemical structures, crystal- linities, thermal stabilities, mechanical properties, hydro- philicities and biodegradabilities of these elastomers were investigated. The hard segments of the linear aliphatic poly （ether-ester） exhibited monoclinic chain packing. Increas- ing the amount of aromatic bisimide moieties in the poly （ether-ester） reduced the crystallinity of the material and improved the thermal stability and tensile strength of the elastomers. In addition, introducing a suitable amount of aromatic bisimide moieties into the poly（ether-ester） backbones endowed the elastomers with improved biode- gradability but too many aromatic bisimide groups reduced the biodegradability of the elastomers.展开更多
基金Supported by the National Natural Science Foundation of China(NSFC 21266019,NSFC 21062011)the Natural Science Fundation of Inner Mongolia(20080404MS020)Program for New Century Excellent Talents in University(NCET-08-858)
文摘The novel alkaline metal complex Ca（BPDCH）2 （1, BPDCH2 = 2,2＇-bipyri- dine-5,5＇-dicarboxylic acid） has been synthesized by the hydrothermal reaction of Ca（NO3）2·4H2O with 2,2＇-bipyridine-5,5＇-dicarboxylic acid. The molecular and crystal structures of complex 1 have firstly been characterized by FTIR, elemental analysis, and X-ray single-crystal diffraction. The 3D MOF structure of complex 1 was interpreted by the versatile binding modes-the intermolecular hydrogen bonds and π-π stacking interactions of 2,2＇-bipyridine-5,5＇-dicarboxylic acid ligand. The analysis results show complex 1 belongs to a coordination polymer with 3D MOF structure. The results of thermogravimetric analysis and solubility demonstrate complex 1 is a thermostable compound and does not dissolve in water and traditional organic solvents.
文摘This paper presents the thermal analysis of artificial sweeteners, and natural sugar substitutes. Thermal analysis was done on commercial compositions of sweeteners using simultaneous DSC/TGA (SDT). Heat flow, and mass vs. temperature and time thermograms, along with DSC peak enthalpies and transition temperatures are reported. A number of the sweeteners were found to undergo transitions and reactions before or at 190°C (375°F, normal baking temperatures) and all dextrose containing sweeteners show an endothermic peak around 80°C due to the liberation of bound water molecules. The major components of sweeteners studied were found to be generally thermostable at or below 100°C.
文摘Abstract Biodegradable poly（ether-imide-ester） elasto- mers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N＇,N-bis（2-carboxyethyl）- pyromellitimide which was derived from pyromellitic dianhydride and glycine. The chemical structures, crystal- linities, thermal stabilities, mechanical properties, hydro- philicities and biodegradabilities of these elastomers were investigated. The hard segments of the linear aliphatic poly （ether-ester） exhibited monoclinic chain packing. Increas- ing the amount of aromatic bisimide moieties in the poly （ether-ester） reduced the crystallinity of the material and improved the thermal stability and tensile strength of the elastomers. In addition, introducing a suitable amount of aromatic bisimide moieties into the poly（ether-ester） backbones endowed the elastomers with improved biode- gradability but too many aromatic bisimide groups reduced the biodegradability of the elastomers.
