液晶聚合物调控的蓄热调温材料的储热性能

Heat storage properties of temperature-regulated materials controlled by liquid crystal polymer

通过3,3′,4,4′-二苯甲酮四甲酸二酐(BPTCD)与聚乙二醇2000(PEG2000)的酯化反应,制备了具有光热响应的相变聚合物BPTCD-PEG,该聚合物在相变过程中可以形成液晶态。在偏光显微镜下,BPTCD-PEG呈典型的焦锥花形向列相液晶织构。采用DSC对BPTCD-PEG的热性能进行表征,结果表明,BPTCD-PEG在41.7℃出现明显的熔融峰,相变潜热为80.42J/g,在30.7℃出现明显结晶峰,对应潜热为63.71J/g,表明BPTCD-PEG具有蓄热调温性能。将该聚合物接枝到棉纤维上,获得了具有蓄热调温性能的纤维素液晶复合材料。对其整理后棉织物表面形貌进行了表征并测试了棉织物的调温性能。在30~40℃内,采用红外热成像仪记录了未整理原棉织物及质量分数为80%的BPTCD-PEG水溶液接枝后的复合材料在不同温度、时间下的升温、降温速率。接枝后的复合材料与未整理原棉织物相比,升温速率与降温速率都明显降低,说明BPTCD-PEG起到了升温过程中降低棉织物的表面温度、降温过程中升高棉织物的表面温度的作用,表明在此温度范围内,经BPTCD-PEG整理后的棉织物具有蓄热调温性能。

Phase change polymer BPTCD-PEG was synthesized by esterification reaction between 3,3′,4,4′-benzophenone tetracarboxylic dianhydride(BPTCD)and polyethylene glycol 2000(PEG2000).BPTCD-PEG could form liquid crystal state during the phase change transition process and show a typical focal cone-shaped nematic liquid crystal texture under polarized optical microscope.The thermal properties of BPTCD-PEG were characterized by DSC.The results showed that there was an obvious melting peak at 41.7℃and a crystalline peak at 30.7℃,and the latent heat of phase transition was 80.42 J/g and 63.71 J/g,respectively,indicating that BPTCD-PEG had remarkable heat storage and temperature regulation performance.BPTCD-PEG was grafted onto cotton fabric to prepare cellulose liquid crystal composites with heat storage and temperature regulation properties.The surface morphology of the modified cotton fabrics was characterized and the thermal regulation properties were tested.In the temperature range of 30~40℃,the heating and cooling rates at different temperature and time of unmodified pure cotton and modified cotton with 80%BPTCD-PEG were recorded using infrared thermal imager.Compared with the unmodified pure cotton,both heating rate and cooling rate of the modified cotton fabric were significantly lower.During the heating process,BPTCD-PEG decreased the surface temperature of cotton fabric,and during the cooling process,BPTCD-PEG increased the surface temperature,which suggested that the cotton fabric treated by BPTCD-PEG had the property of heat storage and temperature regulation in this temperature range.