A type of heat-curing phosphate binder was proposed,and orthogonal experiments based on the tensile strength of sand samples determined that the optimal composition of the binder was phosphoric acid:water:aluminum hyd...A type of heat-curing phosphate binder was proposed,and orthogonal experiments based on the tensile strength of sand samples determined that the optimal composition of the binder was phosphoric acid:water:aluminum hydroxide:magnesium oxide:boric acid=300:70:60:9:8.Adding 10%polyvinyl alcohol(PVA)solution during the sand mixture process can significantly improve the 24 h tensile strength of sand samples.When adding 30 g phosphate binder and 8 g 10%PVA solution,the initial tensile strength of the sample is 0.76 MPa,the room temperature tensile strength is 2.29 MPa,and the 24 h tensile strength is 1.73 MPa.The heat-curing modified phosphate sand mold has high tensile strength and low gas generation,which can meet general casting production requirements.展开更多
We have shown that some phenylethynylsilicon compounds are good cure crosslinkersof heat-curable silicone rubber(HCSR). In this paper the effects of 1, 1, 3, 3-tetramethyl-1, 3-diphenylethynyldisiloxane (TMDPDS) as a ...We have shown that some phenylethynylsilicon compounds are good cure crosslinkersof heat-curable silicone rubber(HCSR). In this paper the effects of 1, 1, 3, 3-tetramethyl-1, 3-diphenylethynyldisiloxane (TMDPDS) as a crosslinker on HCSR were studied. Thevulcanizates with fine mechanical properties could be obtained with suitable amounts ofTMDPDS. Sol fractions, and crosslinking density of vulcanizates and vulcanizationretardation effect of TMDPDS on hydrosilation curing silicone rubber were also discussed.展开更多
The compressive strength and flexural strength with the same strength class cement mortar of the alkali-resistant glass fiber cement mortar were tested in standard and hot-water curing condition, and the damage mechan...The compressive strength and flexural strength with the same strength class cement mortar of the alkali-resistant glass fiber cement mortar were tested in standard and hot-water curing condition, and the damage mechanism of alkali-resistant glass fiber was studied. The interaction mechanisms of the chemical erosion and physical injury in different curing conditions were studied in order to summarize the damage mechanism of alkali-resistant glass fiber in cement-based materials, and chloride diffusivity coefficient and porosity of cement mortar were tested in the different curing conditions. The experimental results are that the strength of cement based materials and fiber cement slurry interface zone were closely related, and heat curing could accelerate the hydration of cement, but inevitably enlarge the defect.展开更多
文摘A type of heat-curing phosphate binder was proposed,and orthogonal experiments based on the tensile strength of sand samples determined that the optimal composition of the binder was phosphoric acid:water:aluminum hydroxide:magnesium oxide:boric acid=300:70:60:9:8.Adding 10%polyvinyl alcohol(PVA)solution during the sand mixture process can significantly improve the 24 h tensile strength of sand samples.When adding 30 g phosphate binder and 8 g 10%PVA solution,the initial tensile strength of the sample is 0.76 MPa,the room temperature tensile strength is 2.29 MPa,and the 24 h tensile strength is 1.73 MPa.The heat-curing modified phosphate sand mold has high tensile strength and low gas generation,which can meet general casting production requirements.
文摘We have shown that some phenylethynylsilicon compounds are good cure crosslinkersof heat-curable silicone rubber(HCSR). In this paper the effects of 1, 1, 3, 3-tetramethyl-1, 3-diphenylethynyldisiloxane (TMDPDS) as a crosslinker on HCSR were studied. Thevulcanizates with fine mechanical properties could be obtained with suitable amounts ofTMDPDS. Sol fractions, and crosslinking density of vulcanizates and vulcanizationretardation effect of TMDPDS on hydrosilation curing silicone rubber were also discussed.
基金Funded by the National Natural Science Foundation of China(Nos.51009015and50872015)the Education Foundation of Liaoning Province(No.L2010038)
文摘The compressive strength and flexural strength with the same strength class cement mortar of the alkali-resistant glass fiber cement mortar were tested in standard and hot-water curing condition, and the damage mechanism of alkali-resistant glass fiber was studied. The interaction mechanisms of the chemical erosion and physical injury in different curing conditions were studied in order to summarize the damage mechanism of alkali-resistant glass fiber in cement-based materials, and chloride diffusivity coefficient and porosity of cement mortar were tested in the different curing conditions. The experimental results are that the strength of cement based materials and fiber cement slurry interface zone were closely related, and heat curing could accelerate the hydration of cement, but inevitably enlarge the defect.