调控聚氨酯发泡材料中的热分布控制高温体积收缩和泡孔结构

Tuning heat distribution in polyurethane foams to control heating volume shrinkage and cellular morphology

为解决在烤漆等高温环境下,车内发泡材料因体积收缩(空隙)而导致的阻隔、缓震作用失效及行驶风噪等问题,以高导热铜粉为改性填料、软质和硬质聚氨酯发泡材料为基体,制备并研究了不同的聚氨酯/铜粉复合材料。结果发现:铜粉含量不仅能有效控制发泡材料在高温下体积收缩现象,且泡孔尺寸和发泡密度也能得到提高;当铜粉含量达到4 wt.%时,软质和硬质聚氨酯发泡材料的体积收缩率分别降低为6.56%和1.77%,发泡密度分别达到0.106 g/cm^(3)和0.171 g/cm^(3),发泡材料的吸水率降低50%左右。因此,添加铜粉后的聚氨酯发泡材料具有防潮和低体积收缩特性。

In high temperature process such as paint-baking,the foams are prone to generate thermal volume shrinkage,resulting in the loss of insulation and shock absorption functions,and it even brings problem of wind noise.In this study,the copper powder with good thermal conductivity was chosen as modified filler,and flexible and rigid polyurethane foams were chosen as matrix.Different polyurethane/copper powder foams were prepared.The results showed that the copper powder content had a significant effect on decrease the volume shrinkage of polyurethane foams under high temperature and on controlling the cellular morphology and foaming density of polyurethane foams.When the content of copper powder reached 4 wt.%,the volume shrinkage and the foaming density of flexible and rigid polyurethane foams decreased to 6.56%and 1.77%,and 0.106 g/cm^(3) and 0.171 g/cm^(3),respectively.In addition,the water absorption of foams also reduced to 50%of pure polyurethane foam with adding copper powder.The use of copper powder modified foams is conducive to the long-term and high-performance use in vehicles field.