硫铝酸盐水泥基复合相变储能砂浆的制备及其性能

采用熔融共混法制备“低密度聚乙烯（LDPE）-石蜡-石墨”复合定形相变材料（SSPCM），并以硫铝酸盐水泥作为胶凝材料，制备了硫铝酸盐水泥基复合相变储能砂浆（TESCCM）。利用SEM、激光扫描共聚焦显微镜（LSCM）、DSC和TGA分析了SSPCM和TESCCM的微观形貌、蓄热能力和热稳定性。通过测试TESCCM的抗压和抗折强度，分析了SSPCM含量对TESCCM力学性能的影响，并利用自制热性能测试箱评价了TESCCM的热调节性能。结果表明：LDPE能够形成多层次网状结构，可实现对相变石蜡的有效包裹，所制备的SSPCM热焓值可达88.02 J/g； SSPCM与水泥基体结合良好； TESCCM具有热稳定性好、强度增长快、早期强度高及调温性能显著等特点。SSPCM含量增加会使TESCCM的强度降低，但对材料的韧性却有所改善。对于SSPCM与水泥质量比为50%的TESCCM，1天和3天抗压强度分别为5.58 MPa和6.51 MPa，28天压折比为2.7。

Preparation and properties of sulphoaluminate cement-based composite phase change storage mortar

Low density polyethylene (LDPE)-paraffin-graphite composite shape stabilization phase change material (SSPCM) was prepared by melt blending method. Thermal energy storage sulphoaluminate cement-based composite mortar (TESCCM) was prepared by using sulphoaluminate cement as cementing material and SSPCM as latent heat storage material. The microstructures, heat storage capacity and thermal stability of SSPCM and TESCCM were analyzed by using SEM, laser scanning confocal microscope(LSCM), DSC and TGA. By testing the compressive and flexural strength of TESCCM, the influence of SSPCM content on the mechanical properties of TESCCM was analyzed, and the thermal regulating property of TESCCM was evaluated by the self-made thermal performance test chamber. The results show that LDPE can form a multi-layered network structure, which can realize the effective encapsulation of phase change paraffin. The latent heat value of the prepared SSPCM can reach 88.02 J/g, and SSPCM is well integrated with the cement matrix; TESCCM has the characteristics of good thermal stability, fast strength growth, high early strength and high tempering performance. Increased SSPCM content reduces the strength of TESCCM, but improves the toughness of TESCCM. The 1 d and 3 d compressive strength of TESCCM(the mass ratio of SSPCM to cement is 50%) were 5.58 MPa and 6.51 MPa, respectively, the ratio of its compressive strength and flexural strength at 28 d is 2.7.