Teflon-pad shaping process of circular metal blanks into quasi-cup specimens is investigated by theoretical and experimental methods in the quasi-static condition. In the experiments, circular metal sheets are formed ...Teflon-pad shaping process of circular metal blanks into quasi-cup specimens is investigated by theoretical and experimental methods in the quasi-static condition. In the experiments, circular metal sheets are formed into the quasi-cup samples by compressing them between a Teflon-filled die and a rigid punch with desirable shape. To investigate influences of different parameters on the forming progress, 12 rigid punches with different dimensions, two blank material types of aluminum and galvanized iron, three blank thicknesses of 0.6, 1.1 and 1.5 mm, and two Teflon-fillers of PVC and polyurethane are used in several experimental tests. In the analytical part, theoretical deformation models of metal blank and Teflon-filler are introduced and based on energy method, energy absorptions by the blank and Teflon-filler are calculated to derive a theoretical formula for predicting total required energy of the forming process. For this purpose, several energy absorption mechanisms are considered in the blank and filler. Furthermore, predictions by theoretical equation are compared with the corresponding experimental tests to study the verity of the calculated formulas. Theoretical and experimental results illustrate change trend of forming energy with respect to blank thickness. Also, the performed forming tests show that when external cone angle of rigid punch with respect to the horizontal direction increases, forming energy increases nonlinearly; and when the depth of spherical part of rigid punch increases, the probability of rupture increases. Additionally, the experiments demonstrate that there is a direct relationship between the forming energy and flow stress of the blanks. Furthermore, experimental observations illustrate that forming energy of a certain blank with PVC Teflon-filler is higher than that of a similar specimen with polyurethane Teflon-filler; but, the probability of wrinkling decreases when PVC Teflon-pad is used as the filler; and it is advantage of PVC Teflon-filler with respect to polyurethane Teflon.展开更多
Increasing demand is fueling the booming polyurethane industry worldwide. An impeding issue for poly- urethane industry is how to handle the large quantity of hydrogen chloride byproduct generated from the synthesis o...Increasing demand is fueling the booming polyurethane industry worldwide. An impeding issue for poly- urethane industry is how to handle the large quantity of hydrogen chloride byproduct generated from the synthesis of intermediates, i.e., isocyanates. In the meantime, the traditional chloro-alkaline process sufibrs both from the high en- ergy intensity of electrolysis method and the disparity in the chlorine and caustic soda market. To solve these prob- lems, the state-of-the-art chlorine recycling technologies are reviewed and compared. Approaches for cost-effective utilization of chlorine in polyurethane industry are investigated. Chinese academies and enterprises' on-going effort on the development of a novel hydrogen chloride oxidation process for the synthesis of chlorine is presented. With this process, the closed loop recycling of chlorine can be realized. Tremendous economic, environmental and social bene- fits can be expected. A wide adoption of this technology will significantly advance the sustainable development of polyurethane industry.展开更多
Two tri(2-chlorobenzyl)tin(IV) complexes with dithiocarbamate ligands (2-Cl- C6H4CH2)3SnS2CN(C5H10) 1 and (2-Cl-C6H4CH2)3SnS2CN(C4H9N) 2 have been synthesized by the reaction of tri(2-chlorobenzyl)tin(IV) chloride wit...Two tri(2-chlorobenzyl)tin(IV) complexes with dithiocarbamate ligands (2-Cl- C6H4CH2)3SnS2CN(C5H10) 1 and (2-Cl-C6H4CH2)3SnS2CN(C4H9N) 2 have been synthesized by the reaction of tri(2-chlorobenzyl)tin(IV) chloride with dithiocarbamates and characterized by elemental analysis, IR and 1H NMR. The crystal structures were determined by X-ray single-crystal diffraction. The crystal of complex 1 belongs to triclinic, space group P with a = 9.121(5), b = 10.788(6), c = 15.549(8) ? a = 77.812(6), b = 88.279(8), g = 72.023(6)o, Z = 2, V = 1421.5(13) ?, Dc = 1.532 g/cm3, ?= 1.344 mm-1, F(000) = 660, R = 0.0382 and wR = 0.0984; and that of complex 2 is of monoclinic, space group P21/n with a = 13.892(10), b = 2.1274(8), c = 2.0553(15) ? b = 107.145(11)o, Z = 4, V = 2726(3) ?, Dc = 1.600 g/cm3, ?= 1.403 mm-1, F(000) = 1320, R = 0.0361 and wR = 0.0826. Their structures show a distorted trigonal bipyramidal configuration with five- coordination for the central tin atoms.展开更多
文摘Teflon-pad shaping process of circular metal blanks into quasi-cup specimens is investigated by theoretical and experimental methods in the quasi-static condition. In the experiments, circular metal sheets are formed into the quasi-cup samples by compressing them between a Teflon-filled die and a rigid punch with desirable shape. To investigate influences of different parameters on the forming progress, 12 rigid punches with different dimensions, two blank material types of aluminum and galvanized iron, three blank thicknesses of 0.6, 1.1 and 1.5 mm, and two Teflon-fillers of PVC and polyurethane are used in several experimental tests. In the analytical part, theoretical deformation models of metal blank and Teflon-filler are introduced and based on energy method, energy absorptions by the blank and Teflon-filler are calculated to derive a theoretical formula for predicting total required energy of the forming process. For this purpose, several energy absorption mechanisms are considered in the blank and filler. Furthermore, predictions by theoretical equation are compared with the corresponding experimental tests to study the verity of the calculated formulas. Theoretical and experimental results illustrate change trend of forming energy with respect to blank thickness. Also, the performed forming tests show that when external cone angle of rigid punch with respect to the horizontal direction increases, forming energy increases nonlinearly; and when the depth of spherical part of rigid punch increases, the probability of rupture increases. Additionally, the experiments demonstrate that there is a direct relationship between the forming energy and flow stress of the blanks. Furthermore, experimental observations illustrate that forming energy of a certain blank with PVC Teflon-filler is higher than that of a similar specimen with polyurethane Teflon-filler; but, the probability of wrinkling decreases when PVC Teflon-pad is used as the filler; and it is advantage of PVC Teflon-filler with respect to polyurethane Teflon.
文摘Increasing demand is fueling the booming polyurethane industry worldwide. An impeding issue for poly- urethane industry is how to handle the large quantity of hydrogen chloride byproduct generated from the synthesis of intermediates, i.e., isocyanates. In the meantime, the traditional chloro-alkaline process sufibrs both from the high en- ergy intensity of electrolysis method and the disparity in the chlorine and caustic soda market. To solve these prob- lems, the state-of-the-art chlorine recycling technologies are reviewed and compared. Approaches for cost-effective utilization of chlorine in polyurethane industry are investigated. Chinese academies and enterprises' on-going effort on the development of a novel hydrogen chloride oxidation process for the synthesis of chlorine is presented. With this process, the closed loop recycling of chlorine can be realized. Tremendous economic, environmental and social bene- fits can be expected. A wide adoption of this technology will significantly advance the sustainable development of polyurethane industry.
基金The National Natural Science Foundation of China (No.20271025) and the Natural Science Foundation of Shandong Province (No. L2003B01)
文摘Two tri(2-chlorobenzyl)tin(IV) complexes with dithiocarbamate ligands (2-Cl- C6H4CH2)3SnS2CN(C5H10) 1 and (2-Cl-C6H4CH2)3SnS2CN(C4H9N) 2 have been synthesized by the reaction of tri(2-chlorobenzyl)tin(IV) chloride with dithiocarbamates and characterized by elemental analysis, IR and 1H NMR. The crystal structures were determined by X-ray single-crystal diffraction. The crystal of complex 1 belongs to triclinic, space group P with a = 9.121(5), b = 10.788(6), c = 15.549(8) ? a = 77.812(6), b = 88.279(8), g = 72.023(6)o, Z = 2, V = 1421.5(13) ?, Dc = 1.532 g/cm3, ?= 1.344 mm-1, F(000) = 660, R = 0.0382 and wR = 0.0984; and that of complex 2 is of monoclinic, space group P21/n with a = 13.892(10), b = 2.1274(8), c = 2.0553(15) ? b = 107.145(11)o, Z = 4, V = 2726(3) ?, Dc = 1.600 g/cm3, ?= 1.403 mm-1, F(000) = 1320, R = 0.0361 and wR = 0.0826. Their structures show a distorted trigonal bipyramidal configuration with five- coordination for the central tin atoms.