聚酰亚胺/羰基铁粉吸波包装材料性能分析

目的 制备聚酰亚胺(PI)/羰基铁粉(CI)复合膜并探究其性能,以改变微波加热过程中的加热方式.方法 主要通过红外光谱、扫描电镜、力学性能、透氧透湿和微波转热测试分析其性能.结果 聚酰亚胺与羰基铁粉是物理结合;当羰基铁粉质量分数超过25％时,开始发生团聚;当羰基铁粉质量分数为20％时,弹性模量最小;当羰基铁粉质量分数为15％时,透氧透湿系数最低;随着羰基铁粉含量的增加,复合膜在微波加热下升温和常温下降温的速率增加.结论 PI/CI复合膜能够吸收部分微波转热能,是一种新型的吸波包装材料,为微波加热用包装材料的设计提供了新思路.

Performance Analysis of Polyimide/Carbonyl Iron Absorbent Packaging Material

This paper amis to improve the thermal insulating performance of insulating containers in cold chain and reduce the consumption of phase change material in short-distance cold chain.In this study, graphene modified phase change macrocapsules were blended with expanded polyurethane (EPU), and graphene modified phase change EPU was prepared as a novel insulating material. The influences of graphene on the thermal conductivity and thermal insulating were discussed, and the phase change heat transfer processes in the prepared graphene modified phase change macrocapsules and novel insulating material were analyzed based on finite element method by using COMSOL Multiphysics.The thermal conduction coefficient of the prepared insulating material increases with the adding of graphene under regular environment temperature, while this coefficient significantly decreases under frozen condition. The system thermal resistance is also improved by blending graphene. The finite element simulation results indicate that the thermal conductivity of phase change macrocapsules increases with the rise of graphene content, and the heating rate is delayed during the temperature plateau stage. This temperature plateau shows an obvious phase change process in the novel insulating material. However, the thermal conductivity of the prepared insulating material significantly increases when the phase change process complete. This transform causes a deterioration of insulating performance of insulating material. The prepared graphene modified phase change EPU can improve the thermal insulation performance of insulating containers during the design storage time and shows a broad application prospect in the short-distance cold chain of fresh fruits and vegetables.