Evaluation of Thermal Endurance Characteristics of Thermosetting Polyurethane Elastomers and Polyurethane Foams by Dynamic Compression Modulus
Evaluation of Thermal Endurance Characteristics of Thermosetting Polyurethane Elastomers and Polyurethane Foams by Dynamic Compression Modulus
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通过动态压缩模量评价热固性聚氨酯弹性体和聚氨酯泡沫的耐热特性
DOI：
10.1295/koron.63.645
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发表时间：
2006
影响因子：
--
通讯作者：
H. Adachi
中科院分区：
文献类型：
--
作者：
H. Adachi
为了评估弹性体和泡沫塑料的耐热性，通过动态粘弹性测量研究了热固性聚氨酯弹性体以及微孔、硬质和软质聚氨酯泡沫的压缩动态模量的时间依赖性。在感兴趣的温度范围（140∼290°C）内，每种弹性体和每种泡沫的压缩动态模量随着时间的推移逐渐减小，这可能是由于弹性体和泡沫的热降解所致。发现压缩动态模量达到动态测量开始时的值的50％时的时间t的对数是温度倒数T-1的线性函数。因此，热固性聚氨酯弹性体和聚氨酯泡沫以及闭孔聚乙烯泡沫的耐热特性可以根据T-1与压缩动态模量达到其初始值的50%时的时间t的对数之间的线性关系来评估。弹性体的损耗角正切与泡沫的损耗角正切不同。热降解由无孔弹性体的压缩变形和具有闭孔或开孔泡沫的弯曲变形决定。
For evaluation of thermal endurance of elastomers and foamed plastics, the time dependences of compression dynamic modulus of thermosetting polyurethane elastomers, and of micro-cell, hard and flexible polyurethane foams were investigated by dynamic viscoelastic measurements. In the temperature range of interest, 140∼290°C, compression dynamic modulus of each elastomer and each foam lessened gradually with time, which is presumably due to thermal degradation of the elastomers and foams. The logarithm of the time t at which the compression dynamic modulus came to be 50% of its value at the beginning of the dynamic measurement was found to be a linear function of reciprocal temperature T-1. Therefore, thermal endurance characteristics of thermosetting polyurethane elastomers and polyurethane foams can be evaluated as well as closed-celled polyethylene foams from the linear relations between T-1 and the logarithm of time t at which the compression dynamic modulus came to be 50% of its initial value. The loss tangent of elastomer differs from that of foam. Thermal degradation is determined by compression deformation in elastomers that have no cells and by the bending deformation in foam that have closed or open cells.