储能磷建筑石膏基的制备与性能研究

Study on Preparation and Properties of Phosphorus Building Gypsum Base for Energy Storage

将石蜡/膨胀蛭石集料掺入磷建筑石膏基质中制备储能磷建筑石膏基材料。在石蜡/膨胀蛭石集料制备过程中,相变石蜡侵入多孔膨胀蛭石,集料暴露于烘箱中恒温(50℃)加热,渗出多余相变石蜡,直到保留稳定的量(66.7%)。采用扫描电子显微镜(SEM)、差示扫描量热(DSC)仪、傅里叶变换红外光谱(FT-IR)仪和热重分析(TGA)仪分别测定储能磷建筑石膏的微观结构、热性能、相容性和热稳定性;此外,石蜡/膨胀蛭石集料分别以0、15%替代磷建筑石膏基体配制两种混合料,评估其力学性能。结果表明,改性石蜡/膨胀蛭石集料表面纳米二氧化硅改善了集料与磷建筑石膏基体的界面裂缝,使储能磷建筑石膏基的力学性能得到改善。同一掺量下,改性集料较普通集料储能磷建筑石膏基材料绝干抗折强度和绝干抗压强度分别提高58.41%、36.89%。石蜡/膨胀蛭石集料的吸热潜热值为95.8 J/g。磷建筑石膏、膨胀蛭石、石蜡之间相容性较好,制备的储能磷建筑石膏有良好的热稳定性。

Energy storage phosphorous building gypsum based materials were prepared by adding paraffin/expanded vermiculite aggregate into phosphorous building gypsum matrix.During the preparation of paraffin/expanded vermiculite aggregate,phase-change paraffin intrudes into the porous expanded vermiculite and is then exposed in an oven at a constant temperature(50℃)to exude excess phase-change paraffin until a stable amount(66.7%)is retained.The microstructure,thermal properties,compatibility and thermal stability of phosphogypsum were determined by scanning electron microscopy(SEM),differential scanning calorimetry(DSC),Fourier transform infrared spectroscopy(FT-IR)and thermogravimetric analyzer(TGA).In addition,two mixtures were prepared by using paraffin/expanded vermiculite aggregate instead of 0 and 15%phosphogypsum matrix to evaluate their mechanical properties.The results show that the nano-silica on the surface of the modified paraffin/expanded vermiculite aggregate improves the interface crack between the aggregate and the phosphogypsum matrix,and improves the mechanical properties of the energy storage phosphogypsum matrix.Under the same dosage,the absolute dry flexural strength and absolute dry compressive strength of the modified aggregate are increased by 58.41%and 36.89%,respectively,compared with the common aggregate.The latent heat of paraffin/expanded vermiculite aggregate is 95.8 J/g.There is good compatibility between phosphorous building gypsum,expanded vermiculite and paraffin wax,the phosphorous building gypsum has good thermal stability.