淀粉膨胀石墨相变复合材料的制备及性能研究

Preparation and properties of starch expanded graphite phase change composites

介绍了一种利用的乳化机理制备淀粉膨胀石墨相变复合材料的方法。以石蜡、膨胀石墨(expanded graphite, EG)和淀粉为原材料,制备淀粉膨胀石墨相变复合材料,并对其性能进行研究。研究表明,红外光谱显示石蜡、EG和淀粉之间是物理结合,没有新物质生成。复合相变材料的储热能力随着相变材料的减少而降低。当EG掺量<8.4%(质量分数)时,相变热逐渐减少,当EG掺量>8.4%(质量分数)时,相变热急剧减少。相变复合材料热导率随着EG掺量的增加而增大。当EG掺量<8.4%(质量分数)时,热导率逐渐增加。当EG掺量8.4%(质量分数)时,热导率增幅较小。EG的掺量为8.4%和11.0%(质量分数)时,扫描电镜显示淀粉膨胀石墨相变复合材料由许多微小的胶囊颗粒组成。相变材料被稳定的封装在微胶囊中,以防止在相变过程中发生泄露。综合考虑其储热性、导热性和稳定性,研究得到EG在复合相变材料中的最佳掺量为8.4%(质量分数)。

In this paper, a method for preparing starch expanded graphite phase change composites using emulsification mechanism was described. Starch expanded graphite phase change composites were prepared by using paraffin, expanded graphite(EG) and starch as raw materials, and their properties were studied. The infrared spectrum showed that there was a physical bond among paraffin, EG and starch, and no new substances formed. The heat storage capacity of the composite phase change material decreased as the phase change material decreased. When the EG content was less than 8.4 ms%, the phase change heat gradually decreased, and when the EG amount was more than 8.4 ms%, the phase change heat sharply decreased. The thermal conductivity of the phase change composite increased with the increase of EG. When the EG content was less than 8.4 ms%, the thermal conductivity gradually increased. When the EG content was more than 8.4 ms%, the thermal conductivity increased less. When the amount of EG were 8.4 ms% and 11 ms%, scanning electron microscopy showed that the starch expanded graphite phase change composite consisted of many tiny capsule particles. The phase change material was stably encapsulated in the microcapsules to prevent leakage during the phase change. Considering its heat storage, thermal conductivity and stability, the optimum amount of EG in the composite phase change material was 8.4 ms%.