The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. ...The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.展开更多
The effect of pre-aging treatment on the tensile properties,formability and microstructures of 2036 aluminum alloy for automobile body sheets were investigated through the tensile tests,DSC analysis and TEM observatio...The effect of pre-aging treatment on the tensile properties,formability and microstructures of 2036 aluminum alloy for automobile body sheets were investigated through the tensile tests,DSC analysis and TEM observation. The results show that the alloy was softened,which was pre-aged at 180 ℃ within 20 min and then natural aging,namely T4P. However,the yield strength decreases first and then rises. The yield strength of the alloy after T4P(10 min) reach the minimal 202.3 MPa,but the elongation and strain hardening exponent arrive at the maximum,25.5% and 0.26 respectively,which can improve its formability effectively. In the early stage of T4P,GP zones dissolve,and generate some θ″ nuclei,so that the strengthening effect is restrained during the natural aging following the pre-aging. With the increment of pre-aging time,the θ″ phases are formed. The number of the θ″ phases grows,and the strength increases sharply during the paint-bake treatment. In contrast with the 6000 series aluminum alloy for automobile body sheets,the paint-bake hardenability of the 2036 alloy is lower and its yield strength before the paint bake is accordingly higher,which will add the difficulty of forming for the sheet.展开更多
采用硬度测试、室温拉伸、DSC分析、OM、SEM和TEM观察,研究复合添加微量Mn,Cr和Sr元素对汽车车身板用6016铝合金组织、时效硬化性与力学性能的影响。结果表明:添加Mn,Cr和Sr元素有效细化基体合金固溶后的再结晶晶粒并改变合金第二相的...采用硬度测试、室温拉伸、DSC分析、OM、SEM和TEM观察,研究复合添加微量Mn,Cr和Sr元素对汽车车身板用6016铝合金组织、时效硬化性与力学性能的影响。结果表明:添加Mn,Cr和Sr元素有效细化基体合金固溶后的再结晶晶粒并改变合金第二相的种类与分布。在6016合金中添加0.17%Mn+0.089%Cr+0.022%Sr(质量分数),对T4态塑性影响较小,但合金时效硬化速度、峰值硬度和时效态强度提高,模拟烤漆后屈服强度、抗拉强度分别提高27.8%和18.2%,屈服强度提高30 MPa。一方面Mn和Cr弥散相强化合金,另一方面Sr改变热力学平衡。并且Mn,Cr和Sr共同作用促进富铁相转变(β富铁相转变成α富铁相)使过剩Si含量增加,β″相析出激活能从105.7 k J/mol降至94.2 k J/mol,促进β″相弥散均匀析出,最终改善合金力学性能。展开更多
文摘The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.
基金Projects (2005-12) supported by the State Key Laboratory of Advanced Design and Manufacture for Vehicle Body Open Foundation of China
文摘The effect of pre-aging treatment on the tensile properties,formability and microstructures of 2036 aluminum alloy for automobile body sheets were investigated through the tensile tests,DSC analysis and TEM observation. The results show that the alloy was softened,which was pre-aged at 180 ℃ within 20 min and then natural aging,namely T4P. However,the yield strength decreases first and then rises. The yield strength of the alloy after T4P(10 min) reach the minimal 202.3 MPa,but the elongation and strain hardening exponent arrive at the maximum,25.5% and 0.26 respectively,which can improve its formability effectively. In the early stage of T4P,GP zones dissolve,and generate some θ″ nuclei,so that the strengthening effect is restrained during the natural aging following the pre-aging. With the increment of pre-aging time,the θ″ phases are formed. The number of the θ″ phases grows,and the strength increases sharply during the paint-bake treatment. In contrast with the 6000 series aluminum alloy for automobile body sheets,the paint-bake hardenability of the 2036 alloy is lower and its yield strength before the paint bake is accordingly higher,which will add the difficulty of forming for the sheet.
文摘采用硬度测试、室温拉伸、DSC分析、OM、SEM和TEM观察,研究复合添加微量Mn,Cr和Sr元素对汽车车身板用6016铝合金组织、时效硬化性与力学性能的影响。结果表明:添加Mn,Cr和Sr元素有效细化基体合金固溶后的再结晶晶粒并改变合金第二相的种类与分布。在6016合金中添加0.17%Mn+0.089%Cr+0.022%Sr(质量分数),对T4态塑性影响较小,但合金时效硬化速度、峰值硬度和时效态强度提高,模拟烤漆后屈服强度、抗拉强度分别提高27.8%和18.2%,屈服强度提高30 MPa。一方面Mn和Cr弥散相强化合金,另一方面Sr改变热力学平衡。并且Mn,Cr和Sr共同作用促进富铁相转变(β富铁相转变成α富铁相)使过剩Si含量增加,β″相析出激活能从105.7 k J/mol降至94.2 k J/mol,促进β″相弥散均匀析出,最终改善合金力学性能。
