稻秆/Na_2SO_4定形相变板材的制备及性能

Preparation and performance of rice straws/Na_2SO_4 shaped phase change plate

将浸渍有Na2SO4的稻秆与特定组成的硅酸盐水泥浆体拌合,再经模压制得定型相变板材。测试了该板材的拉伸强度、隔热及燃烧性能等,用SEM观察了该板材的显微形貌。结果表明,稻秆能装载自身质量4倍的Na2SO4.10H2O,板材的拉伸强度为0.96 MPa,经30次相变循环后质量损失为1.87%,燃烧等级达GB/T 2408—1996的FH-1级。对于稻秆相变板材,在其受热面温度为80℃,冷面起始温度为14.5℃条件下,冷面达到25℃的时间为17 h,比插入未加Na2SO4的稻秆板材延长了5 h;当受热持续保持5h后,其冷面温度仅上升2.7℃。若以该板材为墙体材料,即使在夏天,在无制冷条件下室内温度可基本不变,具有显著的节能及改善人居环境的效果。

Shaped phase change plate was successfully prepared by impregnating NazSO4 solution in rice straws, using Portland cement as the cementing agent followed by compression molding. The properties of the plate, like tensile-strength, insulation performance, flame retardant properties and so on,were tested, and the microstructure of the plate were also studied by scanning electron microscopy （SEM） .The results show that the rice straws in the plate can encapsulate 4 times Na2SO4 10H2O in＇mass, tensile-strength of the plate was 0.96 MPa. After 30 cycles of phase chalnge,the mass loss was 1.87%,and the burning degree was FH-1 specified in standard GB/T 2408--1996. For shaped phase change plate, when the heated surface temperature was 80 ℃ and the initial cold surface temperature was 14.5 ℃, the needed time for the cold surface temperature rising to 25 ℃ was 17 h, which were 5 h longer than rice straw plates without impregnating Na2SO4 solution. When the heating had maintained for 5 h, the cold surface temperature increased by only 2.7℃. This result reflects that it is significant in energy-saving. With the shaped phase change plate as the wailing materials,people could feel comfortable indoor without chilling unit in summer.