用DMA研究聚氨酯泡沫材料的压缩耗能性能

Using DMA to Study Polyurethane Foam Compression Performance

本文提出一种分析泡沫材料抗周期性脉动冲击防护性能的试验方法。运用DMA"低频—高频—低频"周期循环的动态压缩模式,模拟外部冲击脉动压力"弱—强—弱"周期性变化的作用特点。使用该方法对异氰酸酯指数不同的几种低密度聚氨酯泡沫材料进行了试验分析。结果表明,异氰酸酯指数R为1.8的低密度聚氨酯泡沫材料对周期性脉动冲击压力具有较高的损耗因子和耗能模量,与分子结构理论分析一致,该试验方法具有参考价值。

A new test method for analyzing foam protection performance to periodic impulse was proposed. Applying DMA dynamic compress mode of ＂ low frequency-high frequency-low frequency＂ circulation periodically, periodic impulse of ＂weak-strong-weak＂ to objects were simulated. Testing with this method, several kinds of low density polyurethane foam specimens with different isocyanate index were analyzed. Testing results indicate that the low density polyurethane foams with isocyanate index R equal 1.8 have much higher dissipation factor and loss modulus to shock periodically, and accord with the theories of molecular structure, and the test method have a certain reference value.